diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..c795dd7
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,114 @@
+# Makefile for installing Lua
+# See doc/readme.html for installation and customization instructions.
+
+# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT =======================
+
+# Your platform. See PLATS for possible values.
+PLAT= none
+
+# Where to install. The installation starts in the src and doc directories,
+# so take care if INSTALL_TOP is not an absolute path. See the local target.
+# You may want to make INSTALL_LMOD and INSTALL_CMOD consistent with
+# LUA_ROOT, LUA_LDIR, and LUA_CDIR in luaconf.h.
+INSTALL_TOP= /usr/local
+INSTALL_BIN= $(INSTALL_TOP)/bin
+INSTALL_INC= $(INSTALL_TOP)/include
+INSTALL_LIB= $(INSTALL_TOP)/lib
+INSTALL_MAN= $(INSTALL_TOP)/man/man1
+INSTALL_LMOD= $(INSTALL_TOP)/share/lua/$V
+INSTALL_CMOD= $(INSTALL_TOP)/lib/lua/$V
+
+# How to install. If your install program does not support "-p", then
+# you may have to run ranlib on the installed liblua.a.
+INSTALL= install -p
+INSTALL_EXEC= $(INSTALL) -m 0755
+INSTALL_DATA= $(INSTALL) -m 0644
+#
+# If you don't have "install" you can use "cp" instead.
+# INSTALL= cp -p
+# INSTALL_EXEC= $(INSTALL)
+# INSTALL_DATA= $(INSTALL)
+
+# Other utilities.
+MKDIR= mkdir -p
+RM= rm -f
+
+# == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE =======
+
+# Convenience platforms targets.
+PLATS= aix bsd c89 freebsd generic linux macosx mingw posix solaris
+
+# What to install.
+TO_BIN= lua luac
+TO_INC= lua.h luaconf.h lualib.h lauxlib.h lua.hpp
+TO_LIB= liblua.a
+TO_MAN= lua.1 luac.1
+
+# Lua version and release.
+V= 5.3
+R= $V.3
+
+# Targets start here.
+all:	$(PLAT)
+
+$(PLATS) clean:
+	cd src && $(MAKE) $@
+
+test:	dummy
+	src/lua -v
+
+install: dummy
+	cd src && $(MKDIR) $(INSTALL_BIN) $(INSTALL_INC) $(INSTALL_LIB) $(INSTALL_MAN) $(INSTALL_LMOD) $(INSTALL_CMOD)
+	cd src && $(INSTALL_EXEC) $(TO_BIN) $(INSTALL_BIN)
+	cd src && $(INSTALL_DATA) $(TO_INC) $(INSTALL_INC)
+	cd src && $(INSTALL_DATA) $(TO_LIB) $(INSTALL_LIB)
+	cd doc && $(INSTALL_DATA) $(TO_MAN) $(INSTALL_MAN)
+
+uninstall:
+	cd src && cd $(INSTALL_BIN) && $(RM) $(TO_BIN)
+	cd src && cd $(INSTALL_INC) && $(RM) $(TO_INC)
+	cd src && cd $(INSTALL_LIB) && $(RM) $(TO_LIB)
+	cd doc && cd $(INSTALL_MAN) && $(RM) $(TO_MAN)
+
+local:
+	$(MAKE) install INSTALL_TOP=../install
+
+none:
+	@echo "Please do 'make PLATFORM' where PLATFORM is one of these:"
+	@echo "   $(PLATS)"
+	@echo "See doc/readme.html for complete instructions."
+
+# make may get confused with test/ and install/
+dummy:
+
+# echo config parameters
+echo:
+	@cd src && $(MAKE) -s echo
+	@echo "PLAT= $(PLAT)"
+	@echo "V= $V"
+	@echo "R= $R"
+	@echo "TO_BIN= $(TO_BIN)"
+	@echo "TO_INC= $(TO_INC)"
+	@echo "TO_LIB= $(TO_LIB)"
+	@echo "TO_MAN= $(TO_MAN)"
+	@echo "INSTALL_TOP= $(INSTALL_TOP)"
+	@echo "INSTALL_BIN= $(INSTALL_BIN)"
+	@echo "INSTALL_INC= $(INSTALL_INC)"
+	@echo "INSTALL_LIB= $(INSTALL_LIB)"
+	@echo "INSTALL_MAN= $(INSTALL_MAN)"
+	@echo "INSTALL_LMOD= $(INSTALL_LMOD)"
+	@echo "INSTALL_CMOD= $(INSTALL_CMOD)"
+	@echo "INSTALL_EXEC= $(INSTALL_EXEC)"
+	@echo "INSTALL_DATA= $(INSTALL_DATA)"
+
+# echo pkg-config data
+pc:
+	@echo "version=$R"
+	@echo "prefix=$(INSTALL_TOP)"
+	@echo "libdir=$(INSTALL_LIB)"
+	@echo "includedir=$(INSTALL_INC)"
+
+# list targets that do not create files (but not all makes understand .PHONY)
+.PHONY: all $(PLATS) clean test install local none dummy echo pecho lecho
+
+# (end of Makefile)
diff --git a/README b/README
new file mode 100644
index 0000000..e84d9ac
--- /dev/null
+++ b/README
@@ -0,0 +1,6 @@
+
+This is Lua 5.3.3, released on 30 May 2016.
+
+For installation instructions, license details, and
+further information about Lua, see doc/readme.html.
+
diff --git a/doc/contents.html b/doc/contents.html
new file mode 100644
index 0000000..ca0f568
--- /dev/null
+++ b/doc/contents.html
@@ -0,0 +1,618 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<HTML>
+<HEAD>
+<TITLE>Lua 5.3 Reference Manual - contents</TITLE>
+<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css">
+<LINK REL="stylesheet" TYPE="text/css" HREF="index.css">
+<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1">
+</HEAD>
+
+<BODY>
+
+<H1>
+<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua"></A>
+Lua 5.3 Reference Manual
+</H1>
+
+<P>
+The reference manual is the official definition of the Lua language.
+<BR>
+For a complete introduction to Lua programming, see the book
+<A HREF="http://www.lua.org/pil/">Programming in Lua</A>.
+
+<DIV CLASS="menubar">
+<A HREF="manual.html">start</A>
+&middot;
+<A HREF="#contents">contents</A>
+&middot;
+<A HREF="#index">index</A>
+&middot;
+<A HREF="http://www.lua.org/manual/">other versions</A>
+</DIV>
+
+<P>
+<SMALL>
+Copyright &copy; 2015&ndash;2016 Lua.org, PUC-Rio.
+Freely available under the terms of the
+<A HREF="http://www.lua.org/license.html">Lua license</A>.
+</SMALL>
+
+<H2><A NAME="contents">Contents</A></H2>
+<UL CLASS="contents menubar">
+<LI><A HREF="manual.html">1 &ndash; Introduction</A>
+<P>
+<LI><A HREF="manual.html#2">2 &ndash; Basic Concepts</A>
+<UL>
+<LI><A HREF="manual.html#2.1">2.1 &ndash; Values and Types</A>
+<LI><A HREF="manual.html#2.2">2.2 &ndash; Environments and the Global Environment</A>
+<LI><A HREF="manual.html#2.3">2.3 &ndash; Error Handling</A>
+<LI><A HREF="manual.html#2.4">2.4 &ndash; Metatables and Metamethods</A>
+<LI><A HREF="manual.html#2.5">2.5 &ndash; Garbage Collection</A>
+<UL>
+<LI><A HREF="manual.html#2.5.1">2.5.1 &ndash; Garbage-Collection Metamethods</A>
+<LI><A HREF="manual.html#2.5.2">2.5.2 &ndash; Weak Tables</A>
+</UL>
+<LI><A HREF="manual.html#2.6">2.6 &ndash; Coroutines</A>
+</UL>
+<P>
+<LI><A HREF="manual.html#3">3 &ndash; The Language</A>
+<UL>
+<LI><A HREF="manual.html#3.1">3.1 &ndash; Lexical Conventions</A>
+<LI><A HREF="manual.html#3.2">3.2 &ndash; Variables</A>
+<LI><A HREF="manual.html#3.3">3.3 &ndash; Statements</A>
+<UL>
+<LI><A HREF="manual.html#3.3.1">3.3.1 &ndash; Blocks</A>
+<LI><A HREF="manual.html#3.3.2">3.3.2 &ndash; Chunks</A>
+<LI><A HREF="manual.html#3.3.3">3.3.3 &ndash; Assignment</A>
+<LI><A HREF="manual.html#3.3.4">3.3.4 &ndash; Control Structures</A>
+<LI><A HREF="manual.html#3.3.5">3.3.5 &ndash; For Statement</A>
+<LI><A HREF="manual.html#3.3.6">3.3.6 &ndash; Function Calls as Statements</A>
+<LI><A HREF="manual.html#3.3.7">3.3.7 &ndash; Local Declarations</A>
+</UL>
+<LI><A HREF="manual.html#3.4">3.4 &ndash; Expressions</A>
+<UL>
+<LI><A HREF="manual.html#3.4.1">3.4.1 &ndash; Arithmetic Operators</A>
+<LI><A HREF="manual.html#3.4.2">3.4.2 &ndash; Bitwise Operators</A>
+<LI><A HREF="manual.html#3.4.3">3.4.3 &ndash; Coercions and Conversions</A>
+<LI><A HREF="manual.html#3.4.4">3.4.4 &ndash; Relational Operators</A>
+<LI><A HREF="manual.html#3.4.5">3.4.5 &ndash; Logical Operators</A>
+<LI><A HREF="manual.html#3.4.6">3.4.6 &ndash; Concatenation</A>
+<LI><A HREF="manual.html#3.4.7">3.4.7 &ndash; The Length Operator</A>
+<LI><A HREF="manual.html#3.4.8">3.4.8 &ndash; Precedence</A>
+<LI><A HREF="manual.html#3.4.9">3.4.9 &ndash; Table Constructors</A>
+<LI><A HREF="manual.html#3.4.10">3.4.10 &ndash; Function Calls</A>
+<LI><A HREF="manual.html#3.4.11">3.4.11 &ndash; Function Definitions</A>
+</UL>
+<LI><A HREF="manual.html#3.5">3.5 &ndash; Visibility Rules</A>
+</UL>
+<P>
+<LI><A HREF="manual.html#4">4 &ndash; The Application Program Interface</A>
+<UL>
+<LI><A HREF="manual.html#4.1">4.1 &ndash; The Stack</A>
+<LI><A HREF="manual.html#4.2">4.2 &ndash; Stack Size</A>
+<LI><A HREF="manual.html#4.3">4.3 &ndash; Valid and Acceptable Indices</A>
+<LI><A HREF="manual.html#4.4">4.4 &ndash; C Closures</A>
+<LI><A HREF="manual.html#4.5">4.5 &ndash; Registry</A>
+<LI><A HREF="manual.html#4.6">4.6 &ndash; Error Handling in C</A>
+<LI><A HREF="manual.html#4.7">4.7 &ndash; Handling Yields in C</A>
+<LI><A HREF="manual.html#4.8">4.8 &ndash; Functions and Types</A>
+<LI><A HREF="manual.html#4.9">4.9 &ndash; The Debug Interface</A>
+</UL>
+<P>
+<LI><A HREF="manual.html#5">5 &ndash; The Auxiliary Library</A>
+<UL>
+<LI><A HREF="manual.html#5.1">5.1 &ndash; Functions and Types</A>
+</UL>
+<P>
+<LI><A HREF="manual.html#6">6 &ndash; Standard Libraries</A>
+<UL>
+<LI><A HREF="manual.html#6.1">6.1 &ndash; Basic Functions</A>
+<LI><A HREF="manual.html#6.2">6.2 &ndash; Coroutine Manipulation</A>
+<LI><A HREF="manual.html#6.3">6.3 &ndash; Modules</A>
+<LI><A HREF="manual.html#6.4">6.4 &ndash; String Manipulation</A>
+<UL>
+<LI><A HREF="manual.html#6.4.1">6.4.1 &ndash; Patterns</A>
+<LI><A HREF="manual.html#6.4.2">6.4.2 &ndash; Format Strings for Pack and Unpack</A>
+</UL>
+<LI><A HREF="manual.html#6.5">6.5 &ndash; UTF-8 Support</A>
+<LI><A HREF="manual.html#6.6">6.6 &ndash; Table Manipulation</A>
+<LI><A HREF="manual.html#6.7">6.7 &ndash; Mathematical Functions</A>
+<LI><A HREF="manual.html#6.8">6.8 &ndash; Input and Output Facilities</A>
+<LI><A HREF="manual.html#6.9">6.9 &ndash; Operating System Facilities</A>
+<LI><A HREF="manual.html#6.10">6.10 &ndash; The Debug Library</A>
+</UL>
+<P>
+<LI><A HREF="manual.html#7">7 &ndash; Lua Standalone</A>
+<P>
+<LI><A HREF="manual.html#8">8 &ndash; Incompatibilities with the Previous Version</A>
+<UL>
+<LI><A HREF="manual.html#8.1">8.1 &ndash; Changes in the Language</A>
+<LI><A HREF="manual.html#8.2">8.2 &ndash; Changes in the Libraries</A>
+<LI><A HREF="manual.html#8.3">8.3 &ndash; Changes in the API</A>
+</UL>
+<P>
+<LI><A HREF="manual.html#9">9 &ndash; The Complete Syntax of Lua</A>
+</UL>
+
+<H2><A NAME="index">Index</A></H2>
+<TABLE CLASS="menubar" WIDTH="100%">
+<TR>
+<TD>
+<H3><A NAME="functions">Lua functions</A></H3>
+<P>
+<A HREF="manual.html#6.1">basic</A><BR>
+<A HREF="manual.html#pdf-_G">_G</A><BR>
+<A HREF="manual.html#pdf-_VERSION">_VERSION</A><BR>
+<A HREF="manual.html#pdf-assert">assert</A><BR>
+<A HREF="manual.html#pdf-collectgarbage">collectgarbage</A><BR>
+<A HREF="manual.html#pdf-dofile">dofile</A><BR>
+<A HREF="manual.html#pdf-error">error</A><BR>
+<A HREF="manual.html#pdf-getmetatable">getmetatable</A><BR>
+<A HREF="manual.html#pdf-ipairs">ipairs</A><BR>
+<A HREF="manual.html#pdf-load">load</A><BR>
+<A HREF="manual.html#pdf-loadfile">loadfile</A><BR>
+<A HREF="manual.html#pdf-next">next</A><BR>
+<A HREF="manual.html#pdf-pairs">pairs</A><BR>
+<A HREF="manual.html#pdf-pcall">pcall</A><BR>
+<A HREF="manual.html#pdf-print">print</A><BR>
+<A HREF="manual.html#pdf-rawequal">rawequal</A><BR>
+<A HREF="manual.html#pdf-rawget">rawget</A><BR>
+<A HREF="manual.html#pdf-rawlen">rawlen</A><BR>
+<A HREF="manual.html#pdf-rawset">rawset</A><BR>
+<A HREF="manual.html#pdf-require">require</A><BR>
+<A HREF="manual.html#pdf-select">select</A><BR>
+<A HREF="manual.html#pdf-setmetatable">setmetatable</A><BR>
+<A HREF="manual.html#pdf-tonumber">tonumber</A><BR>
+<A HREF="manual.html#pdf-tostring">tostring</A><BR>
+<A HREF="manual.html#pdf-type">type</A><BR>
+<A HREF="manual.html#pdf-xpcall">xpcall</A><BR>
+
+<P>
+<A HREF="manual.html#6.2">coroutine</A><BR>
+<A HREF="manual.html#pdf-coroutine.create">coroutine.create</A><BR>
+<A HREF="manual.html#pdf-coroutine.isyieldable">coroutine.isyieldable</A><BR>
+<A HREF="manual.html#pdf-coroutine.resume">coroutine.resume</A><BR>
+<A HREF="manual.html#pdf-coroutine.running">coroutine.running</A><BR>
+<A HREF="manual.html#pdf-coroutine.status">coroutine.status</A><BR>
+<A HREF="manual.html#pdf-coroutine.wrap">coroutine.wrap</A><BR>
+<A HREF="manual.html#pdf-coroutine.yield">coroutine.yield</A><BR>
+
+<P>
+<A HREF="manual.html#6.10">debug</A><BR>
+<A HREF="manual.html#pdf-debug.debug">debug.debug</A><BR>
+<A HREF="manual.html#pdf-debug.gethook">debug.gethook</A><BR>
+<A HREF="manual.html#pdf-debug.getinfo">debug.getinfo</A><BR>
+<A HREF="manual.html#pdf-debug.getlocal">debug.getlocal</A><BR>
+<A HREF="manual.html#pdf-debug.getmetatable">debug.getmetatable</A><BR>
+<A HREF="manual.html#pdf-debug.getregistry">debug.getregistry</A><BR>
+<A HREF="manual.html#pdf-debug.getupvalue">debug.getupvalue</A><BR>
+<A HREF="manual.html#pdf-debug.getuservalue">debug.getuservalue</A><BR>
+<A HREF="manual.html#pdf-debug.sethook">debug.sethook</A><BR>
+<A HREF="manual.html#pdf-debug.setlocal">debug.setlocal</A><BR>
+<A HREF="manual.html#pdf-debug.setmetatable">debug.setmetatable</A><BR>
+<A HREF="manual.html#pdf-debug.setupvalue">debug.setupvalue</A><BR>
+<A HREF="manual.html#pdf-debug.setuservalue">debug.setuservalue</A><BR>
+<A HREF="manual.html#pdf-debug.traceback">debug.traceback</A><BR>
+<A HREF="manual.html#pdf-debug.upvalueid">debug.upvalueid</A><BR>
+<A HREF="manual.html#pdf-debug.upvaluejoin">debug.upvaluejoin</A><BR>
+
+<P>
+<A HREF="manual.html#6.8">io</A><BR>
+<A HREF="manual.html#pdf-io.close">io.close</A><BR>
+<A HREF="manual.html#pdf-io.flush">io.flush</A><BR>
+<A HREF="manual.html#pdf-io.input">io.input</A><BR>
+<A HREF="manual.html#pdf-io.lines">io.lines</A><BR>
+<A HREF="manual.html#pdf-io.open">io.open</A><BR>
+<A HREF="manual.html#pdf-io.output">io.output</A><BR>
+<A HREF="manual.html#pdf-io.popen">io.popen</A><BR>
+<A HREF="manual.html#pdf-io.read">io.read</A><BR>
+<A HREF="manual.html#pdf-io.stderr">io.stderr</A><BR>
+<A HREF="manual.html#pdf-io.stdin">io.stdin</A><BR>
+<A HREF="manual.html#pdf-io.stdout">io.stdout</A><BR>
+<A HREF="manual.html#pdf-io.tmpfile">io.tmpfile</A><BR>
+<A HREF="manual.html#pdf-io.type">io.type</A><BR>
+<A HREF="manual.html#pdf-io.write">io.write</A><BR>
+
+<A HREF="manual.html#pdf-file:close">file:close</A><BR>
+<A HREF="manual.html#pdf-file:flush">file:flush</A><BR>
+<A HREF="manual.html#pdf-file:lines">file:lines</A><BR>
+<A HREF="manual.html#pdf-file:read">file:read</A><BR>
+<A HREF="manual.html#pdf-file:seek">file:seek</A><BR>
+<A HREF="manual.html#pdf-file:setvbuf">file:setvbuf</A><BR>
+<A HREF="manual.html#pdf-file:write">file:write</A><BR>
+
+</TD>
+<TD>
+<H3>&nbsp;</H3>
+<P>
+<A HREF="manual.html#6.7">math</A><BR>
+<A HREF="manual.html#pdf-math.abs">math.abs</A><BR>
+<A HREF="manual.html#pdf-math.acos">math.acos</A><BR>
+<A HREF="manual.html#pdf-math.asin">math.asin</A><BR>
+<A HREF="manual.html#pdf-math.atan">math.atan</A><BR>
+<A HREF="manual.html#pdf-math.ceil">math.ceil</A><BR>
+<A HREF="manual.html#pdf-math.cos">math.cos</A><BR>
+<A HREF="manual.html#pdf-math.deg">math.deg</A><BR>
+<A HREF="manual.html#pdf-math.exp">math.exp</A><BR>
+<A HREF="manual.html#pdf-math.floor">math.floor</A><BR>
+<A HREF="manual.html#pdf-math.fmod">math.fmod</A><BR>
+<A HREF="manual.html#pdf-math.huge">math.huge</A><BR>
+<A HREF="manual.html#pdf-math.log">math.log</A><BR>
+<A HREF="manual.html#pdf-math.max">math.max</A><BR>
+<A HREF="manual.html#pdf-math.maxinteger">math.maxinteger</A><BR>
+<A HREF="manual.html#pdf-math.min">math.min</A><BR>
+<A HREF="manual.html#pdf-math.mininteger">math.mininteger</A><BR>
+<A HREF="manual.html#pdf-math.modf">math.modf</A><BR>
+<A HREF="manual.html#pdf-math.pi">math.pi</A><BR>
+<A HREF="manual.html#pdf-math.rad">math.rad</A><BR>
+<A HREF="manual.html#pdf-math.random">math.random</A><BR>
+<A HREF="manual.html#pdf-math.randomseed">math.randomseed</A><BR>
+<A HREF="manual.html#pdf-math.sin">math.sin</A><BR>
+<A HREF="manual.html#pdf-math.sqrt">math.sqrt</A><BR>
+<A HREF="manual.html#pdf-math.tan">math.tan</A><BR>
+<A HREF="manual.html#pdf-math.tointeger">math.tointeger</A><BR>
+<A HREF="manual.html#pdf-math.type">math.type</A><BR>
+<A HREF="manual.html#pdf-math.ult">math.ult</A><BR>
+
+<P>
+<A HREF="manual.html#6.9">os</A><BR>
+<A HREF="manual.html#pdf-os.clock">os.clock</A><BR>
+<A HREF="manual.html#pdf-os.date">os.date</A><BR>
+<A HREF="manual.html#pdf-os.difftime">os.difftime</A><BR>
+<A HREF="manual.html#pdf-os.execute">os.execute</A><BR>
+<A HREF="manual.html#pdf-os.exit">os.exit</A><BR>
+<A HREF="manual.html#pdf-os.getenv">os.getenv</A><BR>
+<A HREF="manual.html#pdf-os.remove">os.remove</A><BR>
+<A HREF="manual.html#pdf-os.rename">os.rename</A><BR>
+<A HREF="manual.html#pdf-os.setlocale">os.setlocale</A><BR>
+<A HREF="manual.html#pdf-os.time">os.time</A><BR>
+<A HREF="manual.html#pdf-os.tmpname">os.tmpname</A><BR>
+
+<P>
+<A HREF="manual.html#6.3">package</A><BR>
+<A HREF="manual.html#pdf-package.config">package.config</A><BR>
+<A HREF="manual.html#pdf-package.cpath">package.cpath</A><BR>
+<A HREF="manual.html#pdf-package.loaded">package.loaded</A><BR>
+<A HREF="manual.html#pdf-package.loadlib">package.loadlib</A><BR>
+<A HREF="manual.html#pdf-package.path">package.path</A><BR>
+<A HREF="manual.html#pdf-package.preload">package.preload</A><BR>
+<A HREF="manual.html#pdf-package.searchers">package.searchers</A><BR>
+<A HREF="manual.html#pdf-package.searchpath">package.searchpath</A><BR>
+
+<P>
+<A HREF="manual.html#6.4">string</A><BR>
+<A HREF="manual.html#pdf-string.byte">string.byte</A><BR>
+<A HREF="manual.html#pdf-string.char">string.char</A><BR>
+<A HREF="manual.html#pdf-string.dump">string.dump</A><BR>
+<A HREF="manual.html#pdf-string.find">string.find</A><BR>
+<A HREF="manual.html#pdf-string.format">string.format</A><BR>
+<A HREF="manual.html#pdf-string.gmatch">string.gmatch</A><BR>
+<A HREF="manual.html#pdf-string.gsub">string.gsub</A><BR>
+<A HREF="manual.html#pdf-string.len">string.len</A><BR>
+<A HREF="manual.html#pdf-string.lower">string.lower</A><BR>
+<A HREF="manual.html#pdf-string.match">string.match</A><BR>
+<A HREF="manual.html#pdf-string.pack">string.pack</A><BR>
+<A HREF="manual.html#pdf-string.packsize">string.packsize</A><BR>
+<A HREF="manual.html#pdf-string.rep">string.rep</A><BR>
+<A HREF="manual.html#pdf-string.reverse">string.reverse</A><BR>
+<A HREF="manual.html#pdf-string.sub">string.sub</A><BR>
+<A HREF="manual.html#pdf-string.unpack">string.unpack</A><BR>
+<A HREF="manual.html#pdf-string.upper">string.upper</A><BR>
+
+<P>
+<A HREF="manual.html#6.6">table</A><BR>
+<A HREF="manual.html#pdf-table.concat">table.concat</A><BR>
+<A HREF="manual.html#pdf-table.insert">table.insert</A><BR>
+<A HREF="manual.html#pdf-table.move">table.move</A><BR>
+<A HREF="manual.html#pdf-table.pack">table.pack</A><BR>
+<A HREF="manual.html#pdf-table.remove">table.remove</A><BR>
+<A HREF="manual.html#pdf-table.sort">table.sort</A><BR>
+<A HREF="manual.html#pdf-table.unpack">table.unpack</A><BR>
+
+<P>
+<A HREF="manual.html#6.5">utf8</A><BR>
+<A HREF="manual.html#pdf-utf8.char">utf8.char</A><BR>
+<A HREF="manual.html#pdf-utf8.charpattern">utf8.charpattern</A><BR>
+<A HREF="manual.html#pdf-utf8.codepoint">utf8.codepoint</A><BR>
+<A HREF="manual.html#pdf-utf8.codes">utf8.codes</A><BR>
+<A HREF="manual.html#pdf-utf8.len">utf8.len</A><BR>
+<A HREF="manual.html#pdf-utf8.offset">utf8.offset</A><BR>
+
+<H3><A NAME="env">environment<BR>variables</A></H3>
+<P>
+<A HREF="manual.html#pdf-LUA_CPATH">LUA_CPATH</A><BR>
+<A HREF="manual.html#pdf-LUA_CPATH_5_3">LUA_CPATH_5_3</A><BR>
+<A HREF="manual.html#pdf-LUA_INIT">LUA_INIT</A><BR>
+<A HREF="manual.html#pdf-LUA_INIT_5_3">LUA_INIT_5_3</A><BR>
+<A HREF="manual.html#pdf-LUA_PATH">LUA_PATH</A><BR>
+<A HREF="manual.html#pdf-LUA_PATH_5_3">LUA_PATH_5_3</A><BR>
+
+</TD>
+<TD>
+<H3><A NAME="api">C API</A></H3>
+<P>
+<A HREF="manual.html#lua_Alloc">lua_Alloc</A><BR>
+<A HREF="manual.html#lua_CFunction">lua_CFunction</A><BR>
+<A HREF="manual.html#lua_Debug">lua_Debug</A><BR>
+<A HREF="manual.html#lua_Hook">lua_Hook</A><BR>
+<A HREF="manual.html#lua_Integer">lua_Integer</A><BR>
+<A HREF="manual.html#lua_KContext">lua_KContext</A><BR>
+<A HREF="manual.html#lua_KFunction">lua_KFunction</A><BR>
+<A HREF="manual.html#lua_Number">lua_Number</A><BR>
+<A HREF="manual.html#lua_Reader">lua_Reader</A><BR>
+<A HREF="manual.html#lua_State">lua_State</A><BR>
+<A HREF="manual.html#lua_Unsigned">lua_Unsigned</A><BR>
+<A HREF="manual.html#lua_Writer">lua_Writer</A><BR>
+
+<P>
+<A HREF="manual.html#lua_absindex">lua_absindex</A><BR>
+<A HREF="manual.html#lua_arith">lua_arith</A><BR>
+<A HREF="manual.html#lua_atpanic">lua_atpanic</A><BR>
+<A HREF="manual.html#lua_call">lua_call</A><BR>
+<A HREF="manual.html#lua_callk">lua_callk</A><BR>
+<A HREF="manual.html#lua_checkstack">lua_checkstack</A><BR>
+<A HREF="manual.html#lua_close">lua_close</A><BR>
+<A HREF="manual.html#lua_compare">lua_compare</A><BR>
+<A HREF="manual.html#lua_concat">lua_concat</A><BR>
+<A HREF="manual.html#lua_copy">lua_copy</A><BR>
+<A HREF="manual.html#lua_createtable">lua_createtable</A><BR>
+<A HREF="manual.html#lua_dump">lua_dump</A><BR>
+<A HREF="manual.html#lua_error">lua_error</A><BR>
+<A HREF="manual.html#lua_gc">lua_gc</A><BR>
+<A HREF="manual.html#lua_getallocf">lua_getallocf</A><BR>
+<A HREF="manual.html#lua_getextraspace">lua_getextraspace</A><BR>
+<A HREF="manual.html#lua_getfield">lua_getfield</A><BR>
+<A HREF="manual.html#lua_getglobal">lua_getglobal</A><BR>
+<A HREF="manual.html#lua_gethook">lua_gethook</A><BR>
+<A HREF="manual.html#lua_gethookcount">lua_gethookcount</A><BR>
+<A HREF="manual.html#lua_gethookmask">lua_gethookmask</A><BR>
+<A HREF="manual.html#lua_geti">lua_geti</A><BR>
+<A HREF="manual.html#lua_getinfo">lua_getinfo</A><BR>
+<A HREF="manual.html#lua_getlocal">lua_getlocal</A><BR>
+<A HREF="manual.html#lua_getmetatable">lua_getmetatable</A><BR>
+<A HREF="manual.html#lua_getstack">lua_getstack</A><BR>
+<A HREF="manual.html#lua_gettable">lua_gettable</A><BR>
+<A HREF="manual.html#lua_gettop">lua_gettop</A><BR>
+<A HREF="manual.html#lua_getupvalue">lua_getupvalue</A><BR>
+<A HREF="manual.html#lua_getuservalue">lua_getuservalue</A><BR>
+<A HREF="manual.html#lua_insert">lua_insert</A><BR>
+<A HREF="manual.html#lua_isboolean">lua_isboolean</A><BR>
+<A HREF="manual.html#lua_iscfunction">lua_iscfunction</A><BR>
+<A HREF="manual.html#lua_isfunction">lua_isfunction</A><BR>
+<A HREF="manual.html#lua_isinteger">lua_isinteger</A><BR>
+<A HREF="manual.html#lua_islightuserdata">lua_islightuserdata</A><BR>
+<A HREF="manual.html#lua_isnil">lua_isnil</A><BR>
+<A HREF="manual.html#lua_isnone">lua_isnone</A><BR>
+<A HREF="manual.html#lua_isnoneornil">lua_isnoneornil</A><BR>
+<A HREF="manual.html#lua_isnumber">lua_isnumber</A><BR>
+<A HREF="manual.html#lua_isstring">lua_isstring</A><BR>
+<A HREF="manual.html#lua_istable">lua_istable</A><BR>
+<A HREF="manual.html#lua_isthread">lua_isthread</A><BR>
+<A HREF="manual.html#lua_isuserdata">lua_isuserdata</A><BR>
+<A HREF="manual.html#lua_isyieldable">lua_isyieldable</A><BR>
+<A HREF="manual.html#lua_len">lua_len</A><BR>
+<A HREF="manual.html#lua_load">lua_load</A><BR>
+<A HREF="manual.html#lua_newstate">lua_newstate</A><BR>
+<A HREF="manual.html#lua_newtable">lua_newtable</A><BR>
+<A HREF="manual.html#lua_newthread">lua_newthread</A><BR>
+<A HREF="manual.html#lua_newuserdata">lua_newuserdata</A><BR>
+<A HREF="manual.html#lua_next">lua_next</A><BR>
+<A HREF="manual.html#lua_numbertointeger">lua_numbertointeger</A><BR>
+<A HREF="manual.html#lua_pcall">lua_pcall</A><BR>
+<A HREF="manual.html#lua_pcallk">lua_pcallk</A><BR>
+<A HREF="manual.html#lua_pop">lua_pop</A><BR>
+<A HREF="manual.html#lua_pushboolean">lua_pushboolean</A><BR>
+<A HREF="manual.html#lua_pushcclosure">lua_pushcclosure</A><BR>
+<A HREF="manual.html#lua_pushcfunction">lua_pushcfunction</A><BR>
+<A HREF="manual.html#lua_pushfstring">lua_pushfstring</A><BR>
+<A HREF="manual.html#lua_pushglobaltable">lua_pushglobaltable</A><BR>
+<A HREF="manual.html#lua_pushinteger">lua_pushinteger</A><BR>
+<A HREF="manual.html#lua_pushlightuserdata">lua_pushlightuserdata</A><BR>
+<A HREF="manual.html#lua_pushliteral">lua_pushliteral</A><BR>
+<A HREF="manual.html#lua_pushlstring">lua_pushlstring</A><BR>
+<A HREF="manual.html#lua_pushnil">lua_pushnil</A><BR>
+<A HREF="manual.html#lua_pushnumber">lua_pushnumber</A><BR>
+<A HREF="manual.html#lua_pushstring">lua_pushstring</A><BR>
+<A HREF="manual.html#lua_pushthread">lua_pushthread</A><BR>
+<A HREF="manual.html#lua_pushvalue">lua_pushvalue</A><BR>
+<A HREF="manual.html#lua_pushvfstring">lua_pushvfstring</A><BR>
+<A HREF="manual.html#lua_rawequal">lua_rawequal</A><BR>
+<A HREF="manual.html#lua_rawget">lua_rawget</A><BR>
+<A HREF="manual.html#lua_rawgeti">lua_rawgeti</A><BR>
+<A HREF="manual.html#lua_rawgetp">lua_rawgetp</A><BR>
+<A HREF="manual.html#lua_rawlen">lua_rawlen</A><BR>
+<A HREF="manual.html#lua_rawset">lua_rawset</A><BR>
+<A HREF="manual.html#lua_rawseti">lua_rawseti</A><BR>
+<A HREF="manual.html#lua_rawsetp">lua_rawsetp</A><BR>
+<A HREF="manual.html#lua_register">lua_register</A><BR>
+<A HREF="manual.html#lua_remove">lua_remove</A><BR>
+<A HREF="manual.html#lua_replace">lua_replace</A><BR>
+<A HREF="manual.html#lua_resume">lua_resume</A><BR>
+<A HREF="manual.html#lua_rotate">lua_rotate</A><BR>
+<A HREF="manual.html#lua_setallocf">lua_setallocf</A><BR>
+<A HREF="manual.html#lua_setfield">lua_setfield</A><BR>
+<A HREF="manual.html#lua_setglobal">lua_setglobal</A><BR>
+<A HREF="manual.html#lua_sethook">lua_sethook</A><BR>
+<A HREF="manual.html#lua_seti">lua_seti</A><BR>
+<A HREF="manual.html#lua_setlocal">lua_setlocal</A><BR>
+<A HREF="manual.html#lua_setmetatable">lua_setmetatable</A><BR>
+<A HREF="manual.html#lua_settable">lua_settable</A><BR>
+<A HREF="manual.html#lua_settop">lua_settop</A><BR>
+<A HREF="manual.html#lua_setupvalue">lua_setupvalue</A><BR>
+<A HREF="manual.html#lua_setuservalue">lua_setuservalue</A><BR>
+<A HREF="manual.html#lua_status">lua_status</A><BR>
+<A HREF="manual.html#lua_stringtonumber">lua_stringtonumber</A><BR>
+<A HREF="manual.html#lua_toboolean">lua_toboolean</A><BR>
+<A HREF="manual.html#lua_tocfunction">lua_tocfunction</A><BR>
+<A HREF="manual.html#lua_tointeger">lua_tointeger</A><BR>
+<A HREF="manual.html#lua_tointegerx">lua_tointegerx</A><BR>
+<A HREF="manual.html#lua_tolstring">lua_tolstring</A><BR>
+<A HREF="manual.html#lua_tonumber">lua_tonumber</A><BR>
+<A HREF="manual.html#lua_tonumberx">lua_tonumberx</A><BR>
+<A HREF="manual.html#lua_topointer">lua_topointer</A><BR>
+<A HREF="manual.html#lua_tostring">lua_tostring</A><BR>
+<A HREF="manual.html#lua_tothread">lua_tothread</A><BR>
+<A HREF="manual.html#lua_touserdata">lua_touserdata</A><BR>
+<A HREF="manual.html#lua_type">lua_type</A><BR>
+<A HREF="manual.html#lua_typename">lua_typename</A><BR>
+<A HREF="manual.html#lua_upvalueid">lua_upvalueid</A><BR>
+<A HREF="manual.html#lua_upvalueindex">lua_upvalueindex</A><BR>
+<A HREF="manual.html#lua_upvaluejoin">lua_upvaluejoin</A><BR>
+<A HREF="manual.html#lua_version">lua_version</A><BR>
+<A HREF="manual.html#lua_xmove">lua_xmove</A><BR>
+<A HREF="manual.html#lua_yield">lua_yield</A><BR>
+<A HREF="manual.html#lua_yieldk">lua_yieldk</A><BR>
+
+</TD>
+<TD>
+<H3><A NAME="auxlib">auxiliary library</A></H3>
+<P>
+<A HREF="manual.html#luaL_Buffer">luaL_Buffer</A><BR>
+<A HREF="manual.html#luaL_Reg">luaL_Reg</A><BR>
+<A HREF="manual.html#luaL_Stream">luaL_Stream</A><BR>
+
+<P>
+<A HREF="manual.html#luaL_addchar">luaL_addchar</A><BR>
+<A HREF="manual.html#luaL_addlstring">luaL_addlstring</A><BR>
+<A HREF="manual.html#luaL_addsize">luaL_addsize</A><BR>
+<A HREF="manual.html#luaL_addstring">luaL_addstring</A><BR>
+<A HREF="manual.html#luaL_addvalue">luaL_addvalue</A><BR>
+<A HREF="manual.html#luaL_argcheck">luaL_argcheck</A><BR>
+<A HREF="manual.html#luaL_argerror">luaL_argerror</A><BR>
+<A HREF="manual.html#luaL_buffinit">luaL_buffinit</A><BR>
+<A HREF="manual.html#luaL_buffinitsize">luaL_buffinitsize</A><BR>
+<A HREF="manual.html#luaL_callmeta">luaL_callmeta</A><BR>
+<A HREF="manual.html#luaL_checkany">luaL_checkany</A><BR>
+<A HREF="manual.html#luaL_checkinteger">luaL_checkinteger</A><BR>
+<A HREF="manual.html#luaL_checklstring">luaL_checklstring</A><BR>
+<A HREF="manual.html#luaL_checknumber">luaL_checknumber</A><BR>
+<A HREF="manual.html#luaL_checkoption">luaL_checkoption</A><BR>
+<A HREF="manual.html#luaL_checkstack">luaL_checkstack</A><BR>
+<A HREF="manual.html#luaL_checkstring">luaL_checkstring</A><BR>
+<A HREF="manual.html#luaL_checktype">luaL_checktype</A><BR>
+<A HREF="manual.html#luaL_checkudata">luaL_checkudata</A><BR>
+<A HREF="manual.html#luaL_checkversion">luaL_checkversion</A><BR>
+<A HREF="manual.html#luaL_dofile">luaL_dofile</A><BR>
+<A HREF="manual.html#luaL_dostring">luaL_dostring</A><BR>
+<A HREF="manual.html#luaL_error">luaL_error</A><BR>
+<A HREF="manual.html#luaL_execresult">luaL_execresult</A><BR>
+<A HREF="manual.html#luaL_fileresult">luaL_fileresult</A><BR>
+<A HREF="manual.html#luaL_getmetafield">luaL_getmetafield</A><BR>
+<A HREF="manual.html#luaL_getmetatable">luaL_getmetatable</A><BR>
+<A HREF="manual.html#luaL_getsubtable">luaL_getsubtable</A><BR>
+<A HREF="manual.html#luaL_gsub">luaL_gsub</A><BR>
+<A HREF="manual.html#luaL_len">luaL_len</A><BR>
+<A HREF="manual.html#luaL_loadbuffer">luaL_loadbuffer</A><BR>
+<A HREF="manual.html#luaL_loadbufferx">luaL_loadbufferx</A><BR>
+<A HREF="manual.html#luaL_loadfile">luaL_loadfile</A><BR>
+<A HREF="manual.html#luaL_loadfilex">luaL_loadfilex</A><BR>
+<A HREF="manual.html#luaL_loadstring">luaL_loadstring</A><BR>
+<A HREF="manual.html#luaL_newlib">luaL_newlib</A><BR>
+<A HREF="manual.html#luaL_newlibtable">luaL_newlibtable</A><BR>
+<A HREF="manual.html#luaL_newmetatable">luaL_newmetatable</A><BR>
+<A HREF="manual.html#luaL_newstate">luaL_newstate</A><BR>
+<A HREF="manual.html#luaL_openlibs">luaL_openlibs</A><BR>
+<A HREF="manual.html#luaL_optinteger">luaL_optinteger</A><BR>
+<A HREF="manual.html#luaL_optlstring">luaL_optlstring</A><BR>
+<A HREF="manual.html#luaL_optnumber">luaL_optnumber</A><BR>
+<A HREF="manual.html#luaL_optstring">luaL_optstring</A><BR>
+<A HREF="manual.html#luaL_prepbuffer">luaL_prepbuffer</A><BR>
+<A HREF="manual.html#luaL_prepbuffsize">luaL_prepbuffsize</A><BR>
+<A HREF="manual.html#luaL_pushresult">luaL_pushresult</A><BR>
+<A HREF="manual.html#luaL_pushresultsize">luaL_pushresultsize</A><BR>
+<A HREF="manual.html#luaL_ref">luaL_ref</A><BR>
+<A HREF="manual.html#luaL_requiref">luaL_requiref</A><BR>
+<A HREF="manual.html#luaL_setfuncs">luaL_setfuncs</A><BR>
+<A HREF="manual.html#luaL_setmetatable">luaL_setmetatable</A><BR>
+<A HREF="manual.html#luaL_testudata">luaL_testudata</A><BR>
+<A HREF="manual.html#luaL_tolstring">luaL_tolstring</A><BR>
+<A HREF="manual.html#luaL_traceback">luaL_traceback</A><BR>
+<A HREF="manual.html#luaL_typename">luaL_typename</A><BR>
+<A HREF="manual.html#luaL_unref">luaL_unref</A><BR>
+<A HREF="manual.html#luaL_where">luaL_where</A><BR>
+
+<H3><A NAME="library">standard library</A></H3>
+<P>
+<A HREF="manual.html#pdf-luaopen_base">luaopen_base</A><BR>
+<A HREF="manual.html#pdf-luaopen_coroutine">luaopen_coroutine</A><BR>
+<A HREF="manual.html#pdf-luaopen_debug">luaopen_debug</A><BR>
+<A HREF="manual.html#pdf-luaopen_io">luaopen_io</A><BR>
+<A HREF="manual.html#pdf-luaopen_math">luaopen_math</A><BR>
+<A HREF="manual.html#pdf-luaopen_os">luaopen_os</A><BR>
+<A HREF="manual.html#pdf-luaopen_package">luaopen_package</A><BR>
+<A HREF="manual.html#pdf-luaopen_string">luaopen_string</A><BR>
+<A HREF="manual.html#pdf-luaopen_table">luaopen_table</A><BR>
+<A HREF="manual.html#pdf-luaopen_utf8">luaopen_utf8</A><BR>
+
+<H3><A NAME="constants">constants</A></H3>
+<P>
+<A HREF="manual.html#pdf-LUA_ERRERR">LUA_ERRERR</A><BR>
+<A HREF="manual.html#pdf-LUA_ERRFILE">LUA_ERRFILE</A><BR>
+<A HREF="manual.html#pdf-LUA_ERRGCMM">LUA_ERRGCMM</A><BR>
+<A HREF="manual.html#pdf-LUA_ERRMEM">LUA_ERRMEM</A><BR>
+<A HREF="manual.html#pdf-LUA_ERRRUN">LUA_ERRRUN</A><BR>
+<A HREF="manual.html#pdf-LUA_ERRSYNTAX">LUA_ERRSYNTAX</A><BR>
+<A HREF="manual.html#pdf-LUA_HOOKCALL">LUA_HOOKCALL</A><BR>
+<A HREF="manual.html#pdf-LUA_HOOKCOUNT">LUA_HOOKCOUNT</A><BR>
+<A HREF="manual.html#pdf-LUA_HOOKLINE">LUA_HOOKLINE</A><BR>
+<A HREF="manual.html#pdf-LUA_HOOKRET">LUA_HOOKRET</A><BR>
+<A HREF="manual.html#pdf-LUA_HOOKTAILCALL">LUA_HOOKTAILCALL</A><BR>
+<A HREF="manual.html#pdf-LUA_MASKCALL">LUA_MASKCALL</A><BR>
+<A HREF="manual.html#pdf-LUA_MASKCOUNT">LUA_MASKCOUNT</A><BR>
+<A HREF="manual.html#pdf-LUA_MASKLINE">LUA_MASKLINE</A><BR>
+<A HREF="manual.html#pdf-LUA_MASKRET">LUA_MASKRET</A><BR>
+<A HREF="manual.html#pdf-LUA_MAXINTEGER">LUA_MAXINTEGER</A><BR>
+<A HREF="manual.html#pdf-LUA_MININTEGER">LUA_MININTEGER</A><BR>
+<A HREF="manual.html#pdf-LUA_MINSTACK">LUA_MINSTACK</A><BR>
+<A HREF="manual.html#pdf-LUA_MULTRET">LUA_MULTRET</A><BR>
+<A HREF="manual.html#pdf-LUA_NOREF">LUA_NOREF</A><BR>
+<A HREF="manual.html#pdf-LUA_OK">LUA_OK</A><BR>
+<A HREF="manual.html#pdf-LUA_OPADD">LUA_OPADD</A><BR>
+<A HREF="manual.html#pdf-LUA_OPBAND">LUA_OPBAND</A><BR>
+<A HREF="manual.html#pdf-LUA_OPBNOT">LUA_OPBNOT</A><BR>
+<A HREF="manual.html#pdf-LUA_OPBOR">LUA_OPBOR</A><BR>
+<A HREF="manual.html#pdf-LUA_OPBXOR">LUA_OPBXOR</A><BR>
+<A HREF="manual.html#pdf-LUA_OPDIV">LUA_OPDIV</A><BR>
+<A HREF="manual.html#pdf-LUA_OPEQ">LUA_OPEQ</A><BR>
+<A HREF="manual.html#pdf-LUA_OPIDIV">LUA_OPIDIV</A><BR>
+<A HREF="manual.html#pdf-LUA_OPLE">LUA_OPLE</A><BR>
+<A HREF="manual.html#pdf-LUA_OPLT">LUA_OPLT</A><BR>
+<A HREF="manual.html#pdf-LUA_OPMOD">LUA_OPMOD</A><BR>
+<A HREF="manual.html#pdf-LUA_OPMUL">LUA_OPMUL</A><BR>
+<A HREF="manual.html#pdf-LUA_OPPOW">LUA_OPPOW</A><BR>
+<A HREF="manual.html#pdf-LUA_OPSHL">LUA_OPSHL</A><BR>
+<A HREF="manual.html#pdf-LUA_OPSHR">LUA_OPSHR</A><BR>
+<A HREF="manual.html#pdf-LUA_OPSUB">LUA_OPSUB</A><BR>
+<A HREF="manual.html#pdf-LUA_OPUNM">LUA_OPUNM</A><BR>
+<A HREF="manual.html#pdf-LUA_REFNIL">LUA_REFNIL</A><BR>
+<A HREF="manual.html#pdf-LUA_REGISTRYINDEX">LUA_REGISTRYINDEX</A><BR>
+<A HREF="manual.html#pdf-LUA_RIDX_GLOBALS">LUA_RIDX_GLOBALS</A><BR>
+<A HREF="manual.html#pdf-LUA_RIDX_MAINTHREAD">LUA_RIDX_MAINTHREAD</A><BR>
+<A HREF="manual.html#pdf-LUA_TBOOLEAN">LUA_TBOOLEAN</A><BR>
+<A HREF="manual.html#pdf-LUA_TFUNCTION">LUA_TFUNCTION</A><BR>
+<A HREF="manual.html#pdf-LUA_TLIGHTUSERDATA">LUA_TLIGHTUSERDATA</A><BR>
+<A HREF="manual.html#pdf-LUA_TNIL">LUA_TNIL</A><BR>
+<A HREF="manual.html#pdf-LUA_TNONE">LUA_TNONE</A><BR>
+<A HREF="manual.html#pdf-LUA_TNUMBER">LUA_TNUMBER</A><BR>
+<A HREF="manual.html#pdf-LUA_TSTRING">LUA_TSTRING</A><BR>
+<A HREF="manual.html#pdf-LUA_TTABLE">LUA_TTABLE</A><BR>
+<A HREF="manual.html#pdf-LUA_TTHREAD">LUA_TTHREAD</A><BR>
+<A HREF="manual.html#pdf-LUA_TUSERDATA">LUA_TUSERDATA</A><BR>
+<A HREF="manual.html#pdf-LUA_USE_APICHECK">LUA_USE_APICHECK</A><BR>
+<A HREF="manual.html#pdf-LUA_YIELD">LUA_YIELD</A><BR>
+<A HREF="manual.html#pdf-LUAL_BUFFERSIZE">LUAL_BUFFERSIZE</A><BR>
+
+</TD>
+</TR>
+</TABLE>
+
+<P CLASS="footer">
+Last update:
+Thu Jan 14 10:14:28 BRST 2016
+</P>
+<!--
+Last change: revised for Lua 5.3.3
+-->
+
+</BODY>
+</HTML>
diff --git a/doc/index.css b/doc/index.css
new file mode 100644
index 0000000..c961835
--- /dev/null
+++ b/doc/index.css
@@ -0,0 +1,21 @@
+ul {
+	list-style-type: none ;
+}
+
+ul.contents {
+	padding: 0 ;
+}
+
+table {
+	border: none ;
+	border-spacing: 0 ;
+	border-collapse: collapse ;
+}
+
+td {
+	vertical-align: top ;
+	padding: 0 ;
+	text-align: left ;
+	line-height: 1.25 ;
+	width: 15% ;
+}
diff --git a/doc/logo.gif b/doc/logo.gif
new file mode 100644
index 0000000..2f5e4ac
--- /dev/null
+++ b/doc/logo.gif
Binary files differ
diff --git a/doc/lua.1 b/doc/lua.1
new file mode 100644
index 0000000..411531b
--- /dev/null
+++ b/doc/lua.1
@@ -0,0 +1,111 @@
+.TH LUA 1 "$Date: 2014/12/10 15:55:45 $"
+.SH NAME
+lua \- Lua interpreter
+.SH SYNOPSIS
+.B lua
+[
+.I options
+]
+[
+.I script
+[
+.I args
+]
+]
+.SH DESCRIPTION
+.B lua
+is the standalone Lua interpreter.
+It loads and executes Lua programs,
+either in textual source form or
+in precompiled binary form.
+(Precompiled binaries are output by
+.BR luac ,
+the Lua compiler.)
+.B lua
+can be used as a batch interpreter and also interactively.
+.LP
+The given
+.I options
+are handled in order and then
+the Lua program in file
+.I script
+is loaded and executed.
+The given
+.I args
+are available to
+.I script
+as strings in a global table named
+.BR arg .
+If no options or arguments are given,
+then
+.B "\-v \-i"
+is assumed when the standard input is a terminal;
+otherwise,
+.B "\-"
+is assumed.
+.LP
+In interactive mode,
+.B lua
+prompts the user,
+reads lines from the standard input,
+and executes them as they are read.
+If the line contains an expression or list of expressions,
+then the line is evaluated and the results are printed.
+If a line does not contain a complete statement,
+then a secondary prompt is displayed and
+lines are read until a complete statement is formed or
+a syntax error is found.
+.LP
+At the very start,
+before even handling the command line,
+.B lua
+checks the contents of the environment variables
+.B LUA_INIT_5_3
+or
+.BR LUA_INIT ,
+in that order.
+If the contents is of the form
+.RI '@ filename ',
+then
+.I filename
+is executed.
+Otherwise, the string is assumed to be a Lua statement and is executed.
+.SH OPTIONS
+.TP
+.BI \-e " stat"
+execute statement
+.IR stat .
+.TP
+.B \-i
+enter interactive mode after executing
+.IR script .
+.TP
+.BI \-l " name"
+execute the equivalent of
+.IB name =require(' name ')
+before executing
+.IR script .
+.TP
+.B \-v
+show version information.
+.TP
+.B \-E
+ignore environment variables.
+.TP
+.B \-\-
+stop handling options.
+.TP
+.B \-
+stop handling options and execute the standard input as a file.
+.SH "SEE ALSO"
+.BR luac (1)
+.br
+The documentation at lua.org,
+especially section 7 of the reference manual.
+.SH DIAGNOSTICS
+Error messages should be self explanatory.
+.SH AUTHORS
+R. Ierusalimschy,
+L. H. de Figueiredo,
+W. Celes
+.\" EOF
diff --git a/doc/lua.css b/doc/lua.css
new file mode 100644
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diff --git a/doc/luac.1 b/doc/luac.1
new file mode 100644
index 0000000..33a4ed0
--- /dev/null
+++ b/doc/luac.1
@@ -0,0 +1,118 @@
+.\" $Id: luac.man,v 1.29 2011/11/16 13:53:40 lhf Exp $
+.TH LUAC 1 "$Date: 2011/11/16 13:53:40 $"
+.SH NAME
+luac \- Lua compiler
+.SH SYNOPSIS
+.B luac
+[
+.I options
+] [
+.I filenames
+]
+.SH DESCRIPTION
+.B luac
+is the Lua compiler.
+It translates programs written in the Lua programming language
+into binary files containing precompiled chunks
+that can be later loaded and executed.
+.LP
+The main advantages of precompiling chunks are:
+faster loading,
+protecting source code from accidental user changes,
+and
+off-line syntax checking.
+Precompiling does not imply faster execution
+because in Lua chunks are always compiled into bytecodes before being executed.
+.B luac
+simply allows those bytecodes to be saved in a file for later execution.
+Precompiled chunks are not necessarily smaller than the corresponding source.
+The main goal in precompiling is faster loading.
+.LP
+In the command line,
+you can mix
+text files containing Lua source and
+binary files containing precompiled chunks.
+.B luac
+produces a single output file containing the combined bytecodes
+for all files given.
+Executing the combined file is equivalent to executing the given files.
+By default,
+the output file is named
+.BR luac.out ,
+but you can change this with the
+.B \-o
+option.
+.LP
+Precompiled chunks are
+.I not
+portable across different architectures.
+Moreover,
+the internal format of precompiled chunks
+is likely to change when a new version of Lua is released.
+Make sure you save the source files of all Lua programs that you precompile.
+.LP
+.SH OPTIONS
+.TP
+.B \-l
+produce a listing of the compiled bytecode for Lua's virtual machine.
+Listing bytecodes is useful to learn about Lua's virtual machine.
+If no files are given, then
+.B luac
+loads
+.B luac.out
+and lists its contents.
+Use
+.B \-l \-l
+for a full listing.
+.TP
+.BI \-o " file"
+output to
+.IR file ,
+instead of the default
+.BR luac.out .
+(You can use
+.B "'\-'"
+for standard output,
+but not on platforms that open standard output in text mode.)
+The output file may be one of the given files because
+all files are loaded before the output file is written.
+Be careful not to overwrite precious files.
+.TP
+.B \-p
+load files but do not generate any output file.
+Used mainly for syntax checking and for testing precompiled chunks:
+corrupted files will probably generate errors when loaded.
+If no files are given, then
+.B luac
+loads
+.B luac.out
+and tests its contents.
+No messages are displayed if the file loads without errors.
+.TP
+.B \-s
+strip debug information before writing the output file.
+This saves some space in very large chunks,
+but if errors occur when running a stripped chunk,
+then the error messages may not contain the full information they usually do.
+In particular,
+line numbers and names of local variables are lost.
+.TP
+.B \-v
+show version information.
+.TP
+.B \-\-
+stop handling options.
+.TP
+.B \-
+stop handling options and process standard input.
+.SH "SEE ALSO"
+.BR lua (1)
+.br
+The documentation at lua.org.
+.SH DIAGNOSTICS
+Error messages should be self explanatory.
+.SH AUTHORS
+R. Ierusalimschy,
+L. H. de Figueiredo,
+W. Celes
+.\" EOF
diff --git a/doc/manual.css b/doc/manual.css
new file mode 100644
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diff --git a/doc/manual.html b/doc/manual.html
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@@ -0,0 +1,10910 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<HTML>
+<HEAD>
+<TITLE>Lua 5.3 Reference Manual</TITLE>
+<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css">
+<LINK REL="stylesheet" TYPE="text/css" HREF="manual.css">
+<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1">
+</HEAD>
+
+<BODY>
+
+<H1>
+<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua"></A>
+Lua 5.3 Reference Manual
+</H1>
+
+<P>
+by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes
+
+<P>
+<SMALL>
+Copyright &copy; 2015&ndash;2016 Lua.org, PUC-Rio.
+Freely available under the terms of the
+<a href="http://www.lua.org/license.html">Lua license</a>.
+</SMALL>
+
+<DIV CLASS="menubar">
+<A HREF="contents.html#contents">contents</A>
+&middot;
+<A HREF="contents.html#index">index</A>
+&middot;
+<A HREF="http://www.lua.org/manual/">other versions</A>
+</DIV>
+
+<!-- ====================================================================== -->
+<p>
+
+<!-- $Id: manual.of,v 1.162 2016/05/30 15:57:03 roberto Exp $ -->
+
+
+
+
+<h1>1 &ndash; <a name="1">Introduction</a></h1>
+
+<p>
+Lua is a powerful, efficient, lightweight, embeddable scripting language.
+It supports procedural programming,
+object-oriented programming, functional programming,
+data-driven programming, and data description.
+
+
+<p>
+Lua combines simple procedural syntax with powerful data description
+constructs based on associative arrays and extensible semantics.
+Lua is dynamically typed,
+runs by interpreting bytecode with a register-based
+virtual machine,
+and has automatic memory management with
+incremental garbage collection,
+making it ideal for configuration, scripting,
+and rapid prototyping.
+
+
+<p>
+Lua is implemented as a library, written in <em>clean C</em>,
+the common subset of Standard&nbsp;C and C++.
+The Lua distribution includes a host program called <code>lua</code>,
+which uses the Lua library to offer a complete,
+standalone Lua interpreter,
+for interactive or batch use.
+Lua is intended to be used both as a powerful, lightweight,
+embeddable scripting language for any program that needs one,
+and as a powerful but lightweight and efficient stand-alone language.
+
+
+<p>
+As an extension language, Lua has no notion of a "main" program:
+it works <em>embedded</em> in a host client,
+called the <em>embedding program</em> or simply the <em>host</em>.
+(Frequently, this host is the stand-alone <code>lua</code> program.)
+The host program can invoke functions to execute a piece of Lua code,
+can write and read Lua variables,
+and can register C&nbsp;functions to be called by Lua code.
+Through the use of C&nbsp;functions, Lua can be augmented to cope with
+a wide range of different domains,
+thus creating customized programming languages sharing a syntactical framework.
+
+
+<p>
+Lua is free software,
+and is provided as usual with no guarantees,
+as stated in its license.
+The implementation described in this manual is available
+at Lua's official web site, <code>www.lua.org</code>.
+
+
+<p>
+Like any other reference manual,
+this document is dry in places.
+For a discussion of the decisions behind the design of Lua,
+see the technical papers available at Lua's web site.
+For a detailed introduction to programming in Lua,
+see Roberto's book, <em>Programming in Lua</em>.
+
+
+
+<h1>2 &ndash; <a name="2">Basic Concepts</a></h1>
+
+<p>
+This section describes the basic concepts of the language.
+
+
+
+<h2>2.1 &ndash; <a name="2.1">Values and Types</a></h2>
+
+<p>
+Lua is a <em>dynamically typed language</em>.
+This means that
+variables do not have types; only values do.
+There are no type definitions in the language.
+All values carry their own type.
+
+
+<p>
+All values in Lua are <em>first-class values</em>.
+This means that all values can be stored in variables,
+passed as arguments to other functions, and returned as results.
+
+
+<p>
+There are eight basic types in Lua:
+<em>nil</em>, <em>boolean</em>, <em>number</em>,
+<em>string</em>, <em>function</em>, <em>userdata</em>,
+<em>thread</em>, and <em>table</em>.
+The type <em>nil</em> has one single value, <b>nil</b>,
+whose main property is to be different from any other value;
+it usually represents the absence of a useful value.
+The type <em>boolean</em> has two values, <b>false</b> and <b>true</b>.
+Both <b>nil</b> and <b>false</b> make a condition false;
+any other value makes it true.
+The type <em>number</em> represents both
+integer numbers and real (floating-point) numbers.
+The type <em>string</em> represents immutable sequences of bytes.
+
+Lua is 8-bit clean:
+strings can contain any 8-bit value,
+including embedded zeros ('<code>\0</code>').
+Lua is also encoding-agnostic;
+it makes no assumptions about the contents of a string.
+
+
+<p>
+The type <em>number</em> uses two internal representations,
+or two subtypes,
+one called <em>integer</em> and the other called <em>float</em>.
+Lua has explicit rules about when each representation is used,
+but it also converts between them automatically as needed (see <a href="#3.4.3">&sect;3.4.3</a>).
+Therefore,
+the programmer may choose to mostly ignore the difference
+between integers and floats
+or to assume complete control over the representation of each number.
+Standard Lua uses 64-bit integers and double-precision (64-bit) floats,
+but you can also compile Lua so that it
+uses 32-bit integers and/or single-precision (32-bit) floats.
+The option with 32 bits for both integers and floats
+is particularly attractive
+for small machines and embedded systems.
+(See macro <code>LUA_32BITS</code> in file <code>luaconf.h</code>.)
+
+
+<p>
+Lua can call (and manipulate) functions written in Lua and
+functions written in C (see <a href="#3.4.10">&sect;3.4.10</a>).
+Both are represented by the type <em>function</em>.
+
+
+<p>
+The type <em>userdata</em> is provided to allow arbitrary C&nbsp;data to
+be stored in Lua variables.
+A userdata value represents a block of raw memory.
+There are two kinds of userdata:
+<em>full userdata</em>,
+which is an object with a block of memory managed by Lua,
+and <em>light userdata</em>,
+which is simply a C&nbsp;pointer value.
+Userdata has no predefined operations in Lua,
+except assignment and identity test.
+By using <em>metatables</em>,
+the programmer can define operations for full userdata values
+(see <a href="#2.4">&sect;2.4</a>).
+Userdata values cannot be created or modified in Lua,
+only through the C&nbsp;API.
+This guarantees the integrity of data owned by the host program.
+
+
+<p>
+The type <em>thread</em> represents independent threads of execution
+and it is used to implement coroutines (see <a href="#2.6">&sect;2.6</a>).
+Lua threads are not related to operating-system threads.
+Lua supports coroutines on all systems,
+even those that do not support threads natively.
+
+
+<p>
+The type <em>table</em> implements associative arrays,
+that is, arrays that can be indexed not only with numbers,
+but with any Lua value except <b>nil</b> and NaN.
+(<em>Not a Number</em> is a special value used to represent
+undefined or unrepresentable numerical results, such as <code>0/0</code>.)
+Tables can be <em>heterogeneous</em>;
+that is, they can contain values of all types (except <b>nil</b>).
+Any key with value <b>nil</b> is not considered part of the table.
+Conversely, any key that is not part of a table has
+an associated value <b>nil</b>.
+
+
+<p>
+Tables are the sole data-structuring mechanism in Lua;
+they can be used to represent ordinary arrays, sequences,
+symbol tables, sets, records, graphs, trees, etc.
+To represent records, Lua uses the field name as an index.
+The language supports this representation by
+providing <code>a.name</code> as syntactic sugar for <code>a["name"]</code>.
+There are several convenient ways to create tables in Lua
+(see <a href="#3.4.9">&sect;3.4.9</a>).
+
+
+<p>
+We use the term <em>sequence</em> to denote a table where
+the set of all positive numeric keys is equal to {1..<em>n</em>}
+for some non-negative integer <em>n</em>,
+which is called the length of the sequence (see <a href="#3.4.7">&sect;3.4.7</a>).
+
+
+<p>
+Like indices,
+the values of table fields can be of any type.
+In particular,
+because functions are first-class values,
+table fields can contain functions.
+Thus tables can also carry <em>methods</em> (see <a href="#3.4.11">&sect;3.4.11</a>).
+
+
+<p>
+The indexing of tables follows
+the definition of raw equality in the language.
+The expressions <code>a[i]</code> and <code>a[j]</code>
+denote the same table element
+if and only if <code>i</code> and <code>j</code> are raw equal
+(that is, equal without metamethods).
+In particular, floats with integral values
+are equal to their respective integers
+(e.g., <code>1.0 == 1</code>).
+To avoid ambiguities,
+any float with integral value used as a key
+is converted to its respective integer.
+For instance, if you write <code>a[2.0] = true</code>,
+the actual key inserted into the table will be the
+integer <code>2</code>.
+(On the other hand,
+2 and "<code>2</code>" are different Lua values and therefore
+denote different table entries.)
+
+
+<p>
+Tables, functions, threads, and (full) userdata values are <em>objects</em>:
+variables do not actually <em>contain</em> these values,
+only <em>references</em> to them.
+Assignment, parameter passing, and function returns
+always manipulate references to such values;
+these operations do not imply any kind of copy.
+
+
+<p>
+The library function <a href="#pdf-type"><code>type</code></a> returns a string describing the type
+of a given value (see <a href="#6.1">&sect;6.1</a>).
+
+
+
+
+
+<h2>2.2 &ndash; <a name="2.2">Environments and the Global Environment</a></h2>
+
+<p>
+As will be discussed in <a href="#3.2">&sect;3.2</a> and <a href="#3.3.3">&sect;3.3.3</a>,
+any reference to a free name
+(that is, a name not bound to any declaration) <code>var</code>
+is syntactically translated to <code>_ENV.var</code>.
+Moreover, every chunk is compiled in the scope of
+an external local variable named <code>_ENV</code> (see <a href="#3.3.2">&sect;3.3.2</a>),
+so <code>_ENV</code> itself is never a free name in a chunk.
+
+
+<p>
+Despite the existence of this external <code>_ENV</code> variable and
+the translation of free names,
+<code>_ENV</code> is a completely regular name.
+In particular,
+you can define new variables and parameters with that name.
+Each reference to a free name uses the <code>_ENV</code> that is
+visible at that point in the program,
+following the usual visibility rules of Lua (see <a href="#3.5">&sect;3.5</a>).
+
+
+<p>
+Any table used as the value of <code>_ENV</code> is called an <em>environment</em>.
+
+
+<p>
+Lua keeps a distinguished environment called the <em>global environment</em>.
+This value is kept at a special index in the C registry (see <a href="#4.5">&sect;4.5</a>).
+In Lua, the global variable <a href="#pdf-_G"><code>_G</code></a> is initialized with this same value.
+(<a href="#pdf-_G"><code>_G</code></a> is never used internally.)
+
+
+<p>
+When Lua loads a chunk,
+the default value for its <code>_ENV</code> upvalue
+is the global environment (see <a href="#pdf-load"><code>load</code></a>).
+Therefore, by default,
+free names in Lua code refer to entries in the global environment
+(and, therefore, they are also called <em>global variables</em>).
+Moreover, all standard libraries are loaded in the global environment
+and some functions there operate on that environment.
+You can use <a href="#pdf-load"><code>load</code></a> (or <a href="#pdf-loadfile"><code>loadfile</code></a>)
+to load a chunk with a different environment.
+(In C, you have to load the chunk and then change the value
+of its first upvalue.)
+
+
+
+
+
+<h2>2.3 &ndash; <a name="2.3">Error Handling</a></h2>
+
+<p>
+Because Lua is an embedded extension language,
+all Lua actions start from C&nbsp;code in the host program
+calling a function from the Lua library.
+(When you use Lua standalone,
+the <code>lua</code> application is the host program.)
+Whenever an error occurs during
+the compilation or execution of a Lua chunk,
+control returns to the host,
+which can take appropriate measures
+(such as printing an error message).
+
+
+<p>
+Lua code can explicitly generate an error by calling the
+<a href="#pdf-error"><code>error</code></a> function.
+If you need to catch errors in Lua,
+you can use <a href="#pdf-pcall"><code>pcall</code></a> or <a href="#pdf-xpcall"><code>xpcall</code></a>
+to call a given function in <em>protected mode</em>.
+
+
+<p>
+Whenever there is an error,
+an <em>error object</em> (also called an <em>error message</em>)
+is propagated with information about the error.
+Lua itself only generates errors whose error object is a string,
+but programs may generate errors with
+any value as the error object.
+It is up to the Lua program or its host to handle such error objects.
+
+
+<p>
+When you use <a href="#pdf-xpcall"><code>xpcall</code></a> or <a href="#lua_pcall"><code>lua_pcall</code></a>,
+you may give a <em>message handler</em>
+to be called in case of errors.
+This function is called with the original error object
+and returns a new error object.
+It is called before the error unwinds the stack,
+so that it can gather more information about the error,
+for instance by inspecting the stack and creating a stack traceback.
+This message handler is still protected by the protected call;
+so, an error inside the message handler
+will call the message handler again.
+If this loop goes on for too long,
+Lua breaks it and returns an appropriate message.
+
+
+
+
+
+<h2>2.4 &ndash; <a name="2.4">Metatables and Metamethods</a></h2>
+
+<p>
+Every value in Lua can have a <em>metatable</em>.
+This <em>metatable</em> is an ordinary Lua table
+that defines the behavior of the original value
+under certain special operations.
+You can change several aspects of the behavior
+of operations over a value by setting specific fields in its metatable.
+For instance, when a non-numeric value is the operand of an addition,
+Lua checks for a function in the field "<code>__add</code>" of the value's metatable.
+If it finds one,
+Lua calls this function to perform the addition.
+
+
+<p>
+The key for each event in a metatable is a string
+with the event name prefixed by two underscores;
+the corresponding values are called <em>metamethods</em>.
+In the previous example, the key is "<code>__add</code>"
+and the metamethod is the function that performs the addition.
+
+
+<p>
+You can query the metatable of any value
+using the <a href="#pdf-getmetatable"><code>getmetatable</code></a> function.
+Lua queries metamethods in metatables using a raw access (see <a href="#pdf-rawget"><code>rawget</code></a>).
+So, to retrieve the metamethod for event <code>ev</code> in object <code>o</code>,
+Lua does the equivalent to the following code:
+
+<pre>
+     rawget(getmetatable(<em>o</em>) or {}, "__<em>ev</em>")
+</pre>
+
+<p>
+You can replace the metatable of tables
+using the <a href="#pdf-setmetatable"><code>setmetatable</code></a> function.
+You cannot change the metatable of other types from Lua code
+(except by using the debug library (<a href="#6.10">&sect;6.10</a>));
+you should use the C&nbsp;API for that.
+
+
+<p>
+Tables and full userdata have individual metatables
+(although multiple tables and userdata can share their metatables).
+Values of all other types share one single metatable per type;
+that is, there is one single metatable for all numbers,
+one for all strings, etc.
+By default, a value has no metatable,
+but the string library sets a metatable for the string type (see <a href="#6.4">&sect;6.4</a>).
+
+
+<p>
+A metatable controls how an object behaves in
+arithmetic operations, bitwise operations,
+order comparisons, concatenation, length operation, calls, and indexing.
+A metatable also can define a function to be called
+when a userdata or a table is garbage collected (<a href="#2.5">&sect;2.5</a>).
+
+
+<p>
+For the unary operators (negation, length, and bitwise NOT),
+the metamethod is computed and called with a dummy second operand,
+equal to the first one.
+This extra operand is only to simplify Lua's internals
+(by making these operators behave like a binary operation)
+and may be removed in future versions.
+(For most uses this extra operand is irrelevant.)
+
+
+<p>
+A detailed list of events controlled by metatables is given next.
+Each operation is identified by its corresponding key.
+
+
+
+<ul>
+
+<li><b><code>__add</code>: </b>
+the addition (<code>+</code>) operation.
+If any operand for an addition is not a number
+(nor a string coercible to a number),
+Lua will try to call a metamethod.
+First, Lua will check the first operand (even if it is valid).
+If that operand does not define a metamethod for <code>__add</code>,
+then Lua will check the second operand.
+If Lua can find a metamethod,
+it calls the metamethod with the two operands as arguments,
+and the result of the call
+(adjusted to one value)
+is the result of the operation.
+Otherwise,
+it raises an error.
+</li>
+
+<li><b><code>__sub</code>: </b>
+the subtraction (<code>-</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__mul</code>: </b>
+the multiplication (<code>*</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__div</code>: </b>
+the division (<code>/</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__mod</code>: </b>
+the modulo (<code>%</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__pow</code>: </b>
+the exponentiation (<code>^</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__unm</code>: </b>
+the negation (unary <code>-</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__idiv</code>: </b>
+the floor division (<code>//</code>) operation.
+Behavior similar to the addition operation.
+</li>
+
+<li><b><code>__band</code>: </b>
+the bitwise AND (<code>&amp;</code>) operation.
+Behavior similar to the addition operation,
+except that Lua will try a metamethod
+if any operand is neither an integer
+nor a value coercible to an integer (see <a href="#3.4.3">&sect;3.4.3</a>).
+</li>
+
+<li><b><code>__bor</code>: </b>
+the bitwise OR (<code>|</code>) operation.
+Behavior similar to the bitwise AND operation.
+</li>
+
+<li><b><code>__bxor</code>: </b>
+the bitwise exclusive OR (binary <code>~</code>) operation.
+Behavior similar to the bitwise AND operation.
+</li>
+
+<li><b><code>__bnot</code>: </b>
+the bitwise NOT (unary <code>~</code>) operation.
+Behavior similar to the bitwise AND operation.
+</li>
+
+<li><b><code>__shl</code>: </b>
+the bitwise left shift (<code>&lt;&lt;</code>) operation.
+Behavior similar to the bitwise AND operation.
+</li>
+
+<li><b><code>__shr</code>: </b>
+the bitwise right shift (<code>&gt;&gt;</code>) operation.
+Behavior similar to the bitwise AND operation.
+</li>
+
+<li><b><code>__concat</code>: </b>
+the concatenation (<code>..</code>) operation.
+Behavior similar to the addition operation,
+except that Lua will try a metamethod
+if any operand is neither a string nor a number
+(which is always coercible to a string).
+</li>
+
+<li><b><code>__len</code>: </b>
+the length (<code>#</code>) operation.
+If the object is not a string,
+Lua will try its metamethod.
+If there is a metamethod,
+Lua calls it with the object as argument,
+and the result of the call
+(always adjusted to one value)
+is the result of the operation.
+If there is no metamethod but the object is a table,
+then Lua uses the table length operation (see <a href="#3.4.7">&sect;3.4.7</a>).
+Otherwise, Lua raises an error.
+</li>
+
+<li><b><code>__eq</code>: </b>
+the equal (<code>==</code>) operation.
+Behavior similar to the addition operation,
+except that Lua will try a metamethod only when the values
+being compared are either both tables or both full userdata
+and they are not primitively equal.
+The result of the call is always converted to a boolean.
+</li>
+
+<li><b><code>__lt</code>: </b>
+the less than (<code>&lt;</code>) operation.
+Behavior similar to the addition operation,
+except that Lua will try a metamethod only when the values
+being compared are neither both numbers nor both strings.
+The result of the call is always converted to a boolean.
+</li>
+
+<li><b><code>__le</code>: </b>
+the less equal (<code>&lt;=</code>) operation.
+Unlike other operations,
+the less-equal operation can use two different events.
+First, Lua looks for the <code>__le</code> metamethod in both operands,
+like in the less than operation.
+If it cannot find such a metamethod,
+then it will try the <code>__lt</code> metamethod,
+assuming that <code>a &lt;= b</code> is equivalent to <code>not (b &lt; a)</code>.
+As with the other comparison operators,
+the result is always a boolean.
+(This use of the <code>__lt</code> event can be removed in future versions;
+it is also slower than a real <code>__le</code> metamethod.)
+</li>
+
+<li><b><code>__index</code>: </b>
+The indexing access <code>table[key]</code>.
+This event happens when <code>table</code> is not a table or
+when <code>key</code> is not present in <code>table</code>.
+The metamethod is looked up in <code>table</code>.
+
+
+<p>
+Despite the name,
+the metamethod for this event can be either a function or a table.
+If it is a function,
+it is called with <code>table</code> and <code>key</code> as arguments,
+and the result of the call
+(adjusted to one value)
+is the result of the operation.
+If it is a table,
+the final result is the result of indexing this table with <code>key</code>.
+(This indexing is regular, not raw,
+and therefore can trigger another metamethod.)
+</li>
+
+<li><b><code>__newindex</code>: </b>
+The indexing assignment <code>table[key] = value</code>.
+Like the index event,
+this event happens when <code>table</code> is not a table or
+when <code>key</code> is not present in <code>table</code>.
+The metamethod is looked up in <code>table</code>.
+
+
+<p>
+Like with indexing,
+the metamethod for this event can be either a function or a table.
+If it is a function,
+it is called with <code>table</code>, <code>key</code>, and <code>value</code> as arguments.
+If it is a table,
+Lua does an indexing assignment to this table with the same key and value.
+(This assignment is regular, not raw,
+and therefore can trigger another metamethod.)
+
+
+<p>
+Whenever there is a <code>__newindex</code> metamethod,
+Lua does not perform the primitive assignment.
+(If necessary,
+the metamethod itself can call <a href="#pdf-rawset"><code>rawset</code></a>
+to do the assignment.)
+</li>
+
+<li><b><code>__call</code>: </b>
+The call operation <code>func(args)</code>.
+This event happens when Lua tries to call a non-function value
+(that is, <code>func</code> is not a function).
+The metamethod is looked up in <code>func</code>.
+If present,
+the metamethod is called with <code>func</code> as its first argument,
+followed by the arguments of the original call (<code>args</code>).
+All results of the call
+are the result of the operation.
+(This is the only metamethod that allows multiple results.)
+</li>
+
+</ul>
+
+<p>
+It is a good practice to add all needed metamethods to a table
+before setting it as a metatable of some object.
+In particular, the <code>__gc</code> metamethod works only when this order
+is followed (see <a href="#2.5.1">&sect;2.5.1</a>).
+
+
+<p>
+Because metatables are regular tables,
+they can contain arbitrary fields,
+not only the event names defined above.
+Some functions in the standard library
+(e.g., <a href="#pdf-tostring"><code>tostring</code></a>)
+use other fields in metatables for their own purposes.
+
+
+
+
+
+<h2>2.5 &ndash; <a name="2.5">Garbage Collection</a></h2>
+
+<p>
+Lua performs automatic memory management.
+This means that
+you do not have to worry about allocating memory for new objects
+or freeing it when the objects are no longer needed.
+Lua manages memory automatically by running
+a <em>garbage collector</em> to collect all <em>dead objects</em>
+(that is, objects that are no longer accessible from Lua).
+All memory used by Lua is subject to automatic management:
+strings, tables, userdata, functions, threads, internal structures, etc.
+
+
+<p>
+Lua implements an incremental mark-and-sweep collector.
+It uses two numbers to control its garbage-collection cycles:
+the <em>garbage-collector pause</em> and
+the <em>garbage-collector step multiplier</em>.
+Both use percentage points as units
+(e.g., a value of 100 means an internal value of 1).
+
+
+<p>
+The garbage-collector pause
+controls how long the collector waits before starting a new cycle.
+Larger values make the collector less aggressive.
+Values smaller than 100 mean the collector will not wait to
+start a new cycle.
+A value of 200 means that the collector waits for the total memory in use
+to double before starting a new cycle.
+
+
+<p>
+The garbage-collector step multiplier
+controls the relative speed of the collector relative to
+memory allocation.
+Larger values make the collector more aggressive but also increase
+the size of each incremental step.
+You should not use values smaller than 100,
+because they make the collector too slow and
+can result in the collector never finishing a cycle.
+The default is 200,
+which means that the collector runs at "twice"
+the speed of memory allocation.
+
+
+<p>
+If you set the step multiplier to a very large number
+(larger than 10% of the maximum number of
+bytes that the program may use),
+the collector behaves like a stop-the-world collector.
+If you then set the pause to 200,
+the collector behaves as in old Lua versions,
+doing a complete collection every time Lua doubles its
+memory usage.
+
+
+<p>
+You can change these numbers by calling <a href="#lua_gc"><code>lua_gc</code></a> in C
+or <a href="#pdf-collectgarbage"><code>collectgarbage</code></a> in Lua.
+You can also use these functions to control
+the collector directly (e.g., stop and restart it).
+
+
+
+<h3>2.5.1 &ndash; <a name="2.5.1">Garbage-Collection Metamethods</a></h3>
+
+<p>
+You can set garbage-collector metamethods for tables
+and, using the C&nbsp;API,
+for full userdata (see <a href="#2.4">&sect;2.4</a>).
+These metamethods are also called <em>finalizers</em>.
+Finalizers allow you to coordinate Lua's garbage collection
+with external resource management
+(such as closing files, network or database connections,
+or freeing your own memory).
+
+
+<p>
+For an object (table or userdata) to be finalized when collected,
+you must <em>mark</em> it for finalization.
+
+You mark an object for finalization when you set its metatable
+and the metatable has a field indexed by the string "<code>__gc</code>".
+Note that if you set a metatable without a <code>__gc</code> field
+and later create that field in the metatable,
+the object will not be marked for finalization.
+
+
+<p>
+When a marked object becomes garbage,
+it is not collected immediately by the garbage collector.
+Instead, Lua puts it in a list.
+After the collection,
+Lua goes through that list.
+For each object in the list,
+it checks the object's <code>__gc</code> metamethod:
+If it is a function,
+Lua calls it with the object as its single argument;
+if the metamethod is not a function,
+Lua simply ignores it.
+
+
+<p>
+At the end of each garbage-collection cycle,
+the finalizers for objects are called in
+the reverse order that the objects were marked for finalization,
+among those collected in that cycle;
+that is, the first finalizer to be called is the one associated
+with the object marked last in the program.
+The execution of each finalizer may occur at any point during
+the execution of the regular code.
+
+
+<p>
+Because the object being collected must still be used by the finalizer,
+that object (and other objects accessible only through it)
+must be <em>resurrected</em> by Lua.
+Usually, this resurrection is transient,
+and the object memory is freed in the next garbage-collection cycle.
+However, if the finalizer stores the object in some global place
+(e.g., a global variable),
+then the resurrection is permanent.
+Moreover, if the finalizer marks a finalizing object for finalization again,
+its finalizer will be called again in the next cycle where the
+object is unreachable.
+In any case,
+the object memory is freed only in a GC cycle where
+the object is unreachable and not marked for finalization.
+
+
+<p>
+When you close a state (see <a href="#lua_close"><code>lua_close</code></a>),
+Lua calls the finalizers of all objects marked for finalization,
+following the reverse order that they were marked.
+If any finalizer marks objects for collection during that phase,
+these marks have no effect.
+
+
+
+
+
+<h3>2.5.2 &ndash; <a name="2.5.2">Weak Tables</a></h3>
+
+<p>
+A <em>weak table</em> is a table whose elements are
+<em>weak references</em>.
+A weak reference is ignored by the garbage collector.
+In other words,
+if the only references to an object are weak references,
+then the garbage collector will collect that object.
+
+
+<p>
+A weak table can have weak keys, weak values, or both.
+A table with weak values allows the collection of its values,
+but prevents the collection of its keys.
+A table with both weak keys and weak values allows the collection of
+both keys and values.
+In any case, if either the key or the value is collected,
+the whole pair is removed from the table.
+The weakness of a table is controlled by the
+<code>__mode</code> field of its metatable.
+If the <code>__mode</code> field is a string containing the character&nbsp;'<code>k</code>',
+the keys in the table are weak.
+If <code>__mode</code> contains '<code>v</code>',
+the values in the table are weak.
+
+
+<p>
+A table with weak keys and strong values
+is also called an <em>ephemeron table</em>.
+In an ephemeron table,
+a value is considered reachable only if its key is reachable.
+In particular,
+if the only reference to a key comes through its value,
+the pair is removed.
+
+
+<p>
+Any change in the weakness of a table may take effect only
+at the next collect cycle.
+In particular, if you change the weakness to a stronger mode,
+Lua may still collect some items from that table
+before the change takes effect.
+
+
+<p>
+Only objects that have an explicit construction
+are removed from weak tables.
+Values, such as numbers and light C functions,
+are not subject to garbage collection,
+and therefore are not removed from weak tables
+(unless their associated values are collected).
+Although strings are subject to garbage collection,
+they do not have an explicit construction,
+and therefore are not removed from weak tables.
+
+
+<p>
+Resurrected objects
+(that is, objects being finalized
+and objects accessible only through objects being finalized)
+have a special behavior in weak tables.
+They are removed from weak values before running their finalizers,
+but are removed from weak keys only in the next collection
+after running their finalizers, when such objects are actually freed.
+This behavior allows the finalizer to access properties
+associated with the object through weak tables.
+
+
+<p>
+If a weak table is among the resurrected objects in a collection cycle,
+it may not be properly cleared until the next cycle.
+
+
+
+
+
+
+
+<h2>2.6 &ndash; <a name="2.6">Coroutines</a></h2>
+
+<p>
+Lua supports coroutines,
+also called <em>collaborative multithreading</em>.
+A coroutine in Lua represents an independent thread of execution.
+Unlike threads in multithread systems, however,
+a coroutine only suspends its execution by explicitly calling
+a yield function.
+
+
+<p>
+You create a coroutine by calling <a href="#pdf-coroutine.create"><code>coroutine.create</code></a>.
+Its sole argument is a function
+that is the main function of the coroutine.
+The <code>create</code> function only creates a new coroutine and
+returns a handle to it (an object of type <em>thread</em>);
+it does not start the coroutine.
+
+
+<p>
+You execute a coroutine by calling <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>.
+When you first call <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>,
+passing as its first argument
+a thread returned by <a href="#pdf-coroutine.create"><code>coroutine.create</code></a>,
+the coroutine starts its execution by
+calling its main function.
+Extra arguments passed to <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> are passed
+as arguments to that function.
+After the coroutine starts running,
+it runs until it terminates or <em>yields</em>.
+
+
+<p>
+A coroutine can terminate its execution in two ways:
+normally, when its main function returns
+(explicitly or implicitly, after the last instruction);
+and abnormally, if there is an unprotected error.
+In case of normal termination,
+<a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> returns <b>true</b>,
+plus any values returned by the coroutine main function.
+In case of errors, <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> returns <b>false</b>
+plus an error object.
+
+
+<p>
+A coroutine yields by calling <a href="#pdf-coroutine.yield"><code>coroutine.yield</code></a>.
+When a coroutine yields,
+the corresponding <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> returns immediately,
+even if the yield happens inside nested function calls
+(that is, not in the main function,
+but in a function directly or indirectly called by the main function).
+In the case of a yield, <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> also returns <b>true</b>,
+plus any values passed to <a href="#pdf-coroutine.yield"><code>coroutine.yield</code></a>.
+The next time you resume the same coroutine,
+it continues its execution from the point where it yielded,
+with the call to <a href="#pdf-coroutine.yield"><code>coroutine.yield</code></a> returning any extra
+arguments passed to <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>.
+
+
+<p>
+Like <a href="#pdf-coroutine.create"><code>coroutine.create</code></a>,
+the <a href="#pdf-coroutine.wrap"><code>coroutine.wrap</code></a> function also creates a coroutine,
+but instead of returning the coroutine itself,
+it returns a function that, when called, resumes the coroutine.
+Any arguments passed to this function
+go as extra arguments to <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>.
+<a href="#pdf-coroutine.wrap"><code>coroutine.wrap</code></a> returns all the values returned by <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>,
+except the first one (the boolean error code).
+Unlike <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>,
+<a href="#pdf-coroutine.wrap"><code>coroutine.wrap</code></a> does not catch errors;
+any error is propagated to the caller.
+
+
+<p>
+As an example of how coroutines work,
+consider the following code:
+
+<pre>
+     function foo (a)
+       print("foo", a)
+       return coroutine.yield(2*a)
+     end
+     
+     co = coroutine.create(function (a,b)
+           print("co-body", a, b)
+           local r = foo(a+1)
+           print("co-body", r)
+           local r, s = coroutine.yield(a+b, a-b)
+           print("co-body", r, s)
+           return b, "end"
+     end)
+     
+     print("main", coroutine.resume(co, 1, 10))
+     print("main", coroutine.resume(co, "r"))
+     print("main", coroutine.resume(co, "x", "y"))
+     print("main", coroutine.resume(co, "x", "y"))
+</pre><p>
+When you run it, it produces the following output:
+
+<pre>
+     co-body 1       10
+     foo     2
+     main    true    4
+     co-body r
+     main    true    11      -9
+     co-body x       y
+     main    true    10      end
+     main    false   cannot resume dead coroutine
+</pre>
+
+<p>
+You can also create and manipulate coroutines through the C API:
+see functions <a href="#lua_newthread"><code>lua_newthread</code></a>, <a href="#lua_resume"><code>lua_resume</code></a>,
+and <a href="#lua_yield"><code>lua_yield</code></a>.
+
+
+
+
+
+<h1>3 &ndash; <a name="3">The Language</a></h1>
+
+<p>
+This section describes the lexis, the syntax, and the semantics of Lua.
+In other words,
+this section describes
+which tokens are valid,
+how they can be combined,
+and what their combinations mean.
+
+
+<p>
+Language constructs will be explained using the usual extended BNF notation,
+in which
+{<em>a</em>}&nbsp;means&nbsp;0 or more <em>a</em>'s, and
+[<em>a</em>]&nbsp;means an optional <em>a</em>.
+Non-terminals are shown like non-terminal,
+keywords are shown like <b>kword</b>,
+and other terminal symbols are shown like &lsquo;<b>=</b>&rsquo;.
+The complete syntax of Lua can be found in <a href="#9">&sect;9</a>
+at the end of this manual.
+
+
+
+<h2>3.1 &ndash; <a name="3.1">Lexical Conventions</a></h2>
+
+<p>
+Lua is a free-form language.
+It ignores spaces (including new lines) and comments
+between lexical elements (tokens),
+except as delimiters between names and keywords.
+
+
+<p>
+<em>Names</em>
+(also called <em>identifiers</em>)
+in Lua can be any string of letters,
+digits, and underscores,
+not beginning with a digit and
+not being a reserved word.
+Identifiers are used to name variables, table fields, and labels.
+
+
+<p>
+The following <em>keywords</em> are reserved
+and cannot be used as names:
+
+
+<pre>
+     and       break     do        else      elseif    end
+     false     for       function  goto      if        in
+     local     nil       not       or        repeat    return
+     then      true      until     while
+</pre>
+
+<p>
+Lua is a case-sensitive language:
+<code>and</code> is a reserved word, but <code>And</code> and <code>AND</code>
+are two different, valid names.
+As a convention,
+programs should avoid creating 
+names that start with an underscore followed by
+one or more uppercase letters (such as <a href="#pdf-_VERSION"><code>_VERSION</code></a>).
+
+
+<p>
+The following strings denote other tokens:
+
+<pre>
+     +     -     *     /     %     ^     #
+     &amp;     ~     |     &lt;&lt;    &gt;&gt;    //
+     ==    ~=    &lt;=    &gt;=    &lt;     &gt;     =
+     (     )     {     }     [     ]     ::
+     ;     :     ,     .     ..    ...
+</pre>
+
+<p>
+<em>Literal strings</em>
+can be delimited by matching single or double quotes,
+and can contain the following C-like escape sequences:
+'<code>\a</code>' (bell),
+'<code>\b</code>' (backspace),
+'<code>\f</code>' (form feed),
+'<code>\n</code>' (newline),
+'<code>\r</code>' (carriage return),
+'<code>\t</code>' (horizontal tab),
+'<code>\v</code>' (vertical tab),
+'<code>\\</code>' (backslash),
+'<code>\"</code>' (quotation mark [double quote]),
+and '<code>\'</code>' (apostrophe [single quote]).
+A backslash followed by a real newline
+results in a newline in the string.
+The escape sequence '<code>\z</code>' skips the following span
+of white-space characters,
+including line breaks;
+it is particularly useful to break and indent a long literal string
+into multiple lines without adding the newlines and spaces
+into the string contents.
+
+
+<p>
+Strings in Lua can contain any 8-bit value, including embedded zeros,
+which can be specified as '<code>\0</code>'.
+More generally,
+we can specify any byte in a literal string by its numeric value.
+This can be done
+with the escape sequence <code>\x<em>XX</em></code>,
+where <em>XX</em> is a sequence of exactly two hexadecimal digits,
+or with the escape sequence <code>\<em>ddd</em></code>,
+where <em>ddd</em> is a sequence of up to three decimal digits.
+(Note that if a decimal escape sequence is to be followed by a digit,
+it must be expressed using exactly three digits.)
+
+
+<p>
+The UTF-8 encoding of a Unicode character
+can be inserted in a literal string with
+the escape sequence <code>\u{<em>XXX</em>}</code>
+(note the mandatory enclosing brackets),
+where <em>XXX</em> is a sequence of one or more hexadecimal digits
+representing the character code point.
+
+
+<p>
+Literal strings can also be defined using a long format
+enclosed by <em>long brackets</em>.
+We define an <em>opening long bracket of level <em>n</em></em> as an opening
+square bracket followed by <em>n</em> equal signs followed by another
+opening square bracket.
+So, an opening long bracket of level&nbsp;0 is written as <code>[[</code>, 
+an opening long bracket of level&nbsp;1 is written as <code>[=[</code>, 
+and so on.
+A <em>closing long bracket</em> is defined similarly;
+for instance,
+a closing long bracket of level&nbsp;4 is written as  <code>]====]</code>.
+A <em>long literal</em> starts with an opening long bracket of any level and
+ends at the first closing long bracket of the same level.
+It can contain any text except a closing bracket of the same level.
+Literals in this bracketed form can run for several lines,
+do not interpret any escape sequences,
+and ignore long brackets of any other level.
+Any kind of end-of-line sequence
+(carriage return, newline, carriage return followed by newline,
+or newline followed by carriage return)
+is converted to a simple newline.
+
+
+<p>
+Any byte in a literal string not
+explicitly affected by the previous rules represents itself.
+However, Lua opens files for parsing in text mode,
+and the system file functions may have problems with
+some control characters.
+So, it is safer to represent
+non-text data as a quoted literal with
+explicit escape sequences for the non-text characters.
+
+
+<p>
+For convenience,
+when the opening long bracket is immediately followed by a newline,
+the newline is not included in the string.
+As an example, in a system using ASCII
+(in which '<code>a</code>' is coded as&nbsp;97,
+newline is coded as&nbsp;10, and '<code>1</code>' is coded as&nbsp;49),
+the five literal strings below denote the same string:
+
+<pre>
+     a = 'alo\n123"'
+     a = "alo\n123\""
+     a = '\97lo\10\04923"'
+     a = [[alo
+     123"]]
+     a = [==[
+     alo
+     123"]==]
+</pre>
+
+<p>
+A <em>numeric constant</em> (or <em>numeral</em>)
+can be written with an optional fractional part
+and an optional decimal exponent,
+marked by a letter '<code>e</code>' or '<code>E</code>'.
+Lua also accepts hexadecimal constants,
+which start with <code>0x</code> or <code>0X</code>.
+Hexadecimal constants also accept an optional fractional part
+plus an optional binary exponent,
+marked by a letter '<code>p</code>' or '<code>P</code>'.
+A numeric constant with a radix point or an exponent 
+denotes a float;
+otherwise,
+if its value fits in an integer,
+it denotes an integer.
+Examples of valid integer constants are
+
+<pre>
+     3   345   0xff   0xBEBADA
+</pre><p>
+Examples of valid float constants are
+
+<pre>
+     3.0     3.1416     314.16e-2     0.31416E1     34e1
+     0x0.1E  0xA23p-4   0X1.921FB54442D18P+1
+</pre>
+
+<p>
+A <em>comment</em> starts with a double hyphen (<code>--</code>)
+anywhere outside a string.
+If the text immediately after <code>--</code> is not an opening long bracket,
+the comment is a <em>short comment</em>,
+which runs until the end of the line.
+Otherwise, it is a <em>long comment</em>,
+which runs until the corresponding closing long bracket.
+Long comments are frequently used to disable code temporarily.
+
+
+
+
+
+<h2>3.2 &ndash; <a name="3.2">Variables</a></h2>
+
+<p>
+Variables are places that store values.
+There are three kinds of variables in Lua:
+global variables, local variables, and table fields.
+
+
+<p>
+A single name can denote a global variable or a local variable
+(or a function's formal parameter,
+which is a particular kind of local variable):
+
+<pre>
+	var ::= Name
+</pre><p>
+Name denotes identifiers, as defined in <a href="#3.1">&sect;3.1</a>.
+
+
+<p>
+Any variable name is assumed to be global unless explicitly declared
+as a local (see <a href="#3.3.7">&sect;3.3.7</a>).
+Local variables are <em>lexically scoped</em>:
+local variables can be freely accessed by functions
+defined inside their scope (see <a href="#3.5">&sect;3.5</a>).
+
+
+<p>
+Before the first assignment to a variable, its value is <b>nil</b>.
+
+
+<p>
+Square brackets are used to index a table:
+
+<pre>
+	var ::= prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo;
+</pre><p>
+The meaning of accesses to table fields can be changed via metatables.
+An access to an indexed variable <code>t[i]</code> is equivalent to
+a call <code>gettable_event(t,i)</code>.
+(See <a href="#2.4">&sect;2.4</a> for a complete description of the
+<code>gettable_event</code> function.
+This function is not defined or callable in Lua.
+We use it here only for explanatory purposes.)
+
+
+<p>
+The syntax <code>var.Name</code> is just syntactic sugar for
+<code>var["Name"]</code>:
+
+<pre>
+	var ::= prefixexp &lsquo;<b>.</b>&rsquo; Name
+</pre>
+
+<p>
+An access to a global variable <code>x</code>
+is equivalent to <code>_ENV.x</code>.
+Due to the way that chunks are compiled,
+<code>_ENV</code> is never a global name (see <a href="#2.2">&sect;2.2</a>).
+
+
+
+
+
+<h2>3.3 &ndash; <a name="3.3">Statements</a></h2>
+
+<p>
+Lua supports an almost conventional set of statements,
+similar to those in Pascal or C.
+This set includes
+assignments, control structures, function calls,
+and variable declarations.
+
+
+
+<h3>3.3.1 &ndash; <a name="3.3.1">Blocks</a></h3>
+
+<p>
+A block is a list of statements,
+which are executed sequentially:
+
+<pre>
+	block ::= {stat}
+</pre><p>
+Lua has <em>empty statements</em>
+that allow you to separate statements with semicolons,
+start a block with a semicolon
+or write two semicolons in sequence:
+
+<pre>
+	stat ::= &lsquo;<b>;</b>&rsquo;
+</pre>
+
+<p>
+Function calls and assignments
+can start with an open parenthesis.
+This possibility leads to an ambiguity in Lua's grammar.
+Consider the following fragment:
+
+<pre>
+     a = b + c
+     (print or io.write)('done')
+</pre><p>
+The grammar could see it in two ways:
+
+<pre>
+     a = b + c(print or io.write)('done')
+     
+     a = b + c; (print or io.write)('done')
+</pre><p>
+The current parser always sees such constructions
+in the first way,
+interpreting the open parenthesis
+as the start of the arguments to a call.
+To avoid this ambiguity,
+it is a good practice to always precede with a semicolon
+statements that start with a parenthesis:
+
+<pre>
+     ;(print or io.write)('done')
+</pre>
+
+<p>
+A block can be explicitly delimited to produce a single statement:
+
+<pre>
+	stat ::= <b>do</b> block <b>end</b>
+</pre><p>
+Explicit blocks are useful
+to control the scope of variable declarations.
+Explicit blocks are also sometimes used to
+add a <b>return</b> statement in the middle
+of another block (see <a href="#3.3.4">&sect;3.3.4</a>).
+
+
+
+
+
+<h3>3.3.2 &ndash; <a name="3.3.2">Chunks</a></h3>
+
+<p>
+The unit of compilation of Lua is called a <em>chunk</em>.
+Syntactically,
+a chunk is simply a block:
+
+<pre>
+	chunk ::= block
+</pre>
+
+<p>
+Lua handles a chunk as the body of an anonymous function
+with a variable number of arguments
+(see <a href="#3.4.11">&sect;3.4.11</a>).
+As such, chunks can define local variables,
+receive arguments, and return values.
+Moreover, such anonymous function is compiled as in the
+scope of an external local variable called <code>_ENV</code> (see <a href="#2.2">&sect;2.2</a>).
+The resulting function always has <code>_ENV</code> as its only upvalue,
+even if it does not use that variable.
+
+
+<p>
+A chunk can be stored in a file or in a string inside the host program.
+To execute a chunk,
+Lua first <em>loads</em> it,
+precompiling the chunk's code into instructions for a virtual machine,
+and then Lua executes the compiled code
+with an interpreter for the virtual machine.
+
+
+<p>
+Chunks can also be precompiled into binary form;
+see program <code>luac</code> and function <a href="#pdf-string.dump"><code>string.dump</code></a> for details.
+Programs in source and compiled forms are interchangeable;
+Lua automatically detects the file type and acts accordingly (see <a href="#pdf-load"><code>load</code></a>).
+
+
+
+
+
+<h3>3.3.3 &ndash; <a name="3.3.3">Assignment</a></h3>
+
+<p>
+Lua allows multiple assignments.
+Therefore, the syntax for assignment
+defines a list of variables on the left side
+and a list of expressions on the right side.
+The elements in both lists are separated by commas:
+
+<pre>
+	stat ::= varlist &lsquo;<b>=</b>&rsquo; explist
+	varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
+	explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
+</pre><p>
+Expressions are discussed in <a href="#3.4">&sect;3.4</a>.
+
+
+<p>
+Before the assignment,
+the list of values is <em>adjusted</em> to the length of
+the list of variables.
+If there are more values than needed,
+the excess values are thrown away.
+If there are fewer values than needed,
+the list is extended with as many  <b>nil</b>'s as needed.
+If the list of expressions ends with a function call,
+then all values returned by that call enter the list of values,
+before the adjustment
+(except when the call is enclosed in parentheses; see <a href="#3.4">&sect;3.4</a>).
+
+
+<p>
+The assignment statement first evaluates all its expressions
+and only then the assignments are performed.
+Thus the code
+
+<pre>
+     i = 3
+     i, a[i] = i+1, 20
+</pre><p>
+sets <code>a[3]</code> to 20, without affecting <code>a[4]</code>
+because the <code>i</code> in <code>a[i]</code> is evaluated (to 3)
+before it is assigned&nbsp;4.
+Similarly, the line
+
+<pre>
+     x, y = y, x
+</pre><p>
+exchanges the values of <code>x</code> and <code>y</code>,
+and
+
+<pre>
+     x, y, z = y, z, x
+</pre><p>
+cyclically permutes the values of <code>x</code>, <code>y</code>, and <code>z</code>.
+
+
+<p>
+The meaning of assignments to global variables
+and table fields can be changed via metatables.
+An assignment to an indexed variable <code>t[i] = val</code> is equivalent to
+<code>settable_event(t,i,val)</code>.
+(See <a href="#2.4">&sect;2.4</a> for a complete description of the
+<code>settable_event</code> function.
+This function is not defined or callable in Lua.
+We use it here only for explanatory purposes.)
+
+
+<p>
+An assignment to a global name <code>x = val</code>
+is equivalent to the assignment
+<code>_ENV.x = val</code> (see <a href="#2.2">&sect;2.2</a>).
+
+
+
+
+
+<h3>3.3.4 &ndash; <a name="3.3.4">Control Structures</a></h3><p>
+The control structures
+<b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and
+familiar syntax:
+
+
+
+
+<pre>
+	stat ::= <b>while</b> exp <b>do</b> block <b>end</b>
+	stat ::= <b>repeat</b> block <b>until</b> exp
+	stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b>
+</pre><p>
+Lua also has a <b>for</b> statement, in two flavors (see <a href="#3.3.5">&sect;3.3.5</a>).
+
+
+<p>
+The condition expression of a
+control structure can return any value.
+Both <b>false</b> and <b>nil</b> are considered false.
+All values different from <b>nil</b> and <b>false</b> are considered true
+(in particular, the number 0 and the empty string are also true).
+
+
+<p>
+In the <b>repeat</b>&ndash;<b>until</b> loop,
+the inner block does not end at the <b>until</b> keyword,
+but only after the condition.
+So, the condition can refer to local variables
+declared inside the loop block.
+
+
+<p>
+The <b>goto</b> statement transfers the program control to a label.
+For syntactical reasons,
+labels in Lua are considered statements too:
+
+
+
+<pre>
+	stat ::= <b>goto</b> Name
+	stat ::= label
+	label ::= &lsquo;<b>::</b>&rsquo; Name &lsquo;<b>::</b>&rsquo;
+</pre>
+
+<p>
+A label is visible in the entire block where it is defined,
+except
+inside nested blocks where a label with the same name is defined and
+inside nested functions.
+A goto may jump to any visible label as long as it does not
+enter into the scope of a local variable.
+
+
+<p>
+Labels and empty statements are called <em>void statements</em>,
+as they perform no actions.
+
+
+<p>
+The <b>break</b> statement terminates the execution of a
+<b>while</b>, <b>repeat</b>, or <b>for</b> loop,
+skipping to the next statement after the loop:
+
+
+<pre>
+	stat ::= <b>break</b>
+</pre><p>
+A <b>break</b> ends the innermost enclosing loop.
+
+
+<p>
+The <b>return</b> statement is used to return values
+from a function or a chunk
+(which is an anonymous function).
+
+Functions can return more than one value,
+so the syntax for the <b>return</b> statement is
+
+<pre>
+	stat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
+</pre>
+
+<p>
+The <b>return</b> statement can only be written
+as the last statement of a block.
+If it is really necessary to <b>return</b> in the middle of a block,
+then an explicit inner block can be used,
+as in the idiom <code>do return end</code>,
+because now <b>return</b> is the last statement in its (inner) block.
+
+
+
+
+
+<h3>3.3.5 &ndash; <a name="3.3.5">For Statement</a></h3>
+
+<p>
+
+The <b>for</b> statement has two forms:
+one numerical and one generic.
+
+
+<p>
+The numerical <b>for</b> loop repeats a block of code while a
+control variable runs through an arithmetic progression.
+It has the following syntax:
+
+<pre>
+	stat ::= <b>for</b> Name &lsquo;<b>=</b>&rsquo; exp &lsquo;<b>,</b>&rsquo; exp [&lsquo;<b>,</b>&rsquo; exp] <b>do</b> block <b>end</b>
+</pre><p>
+The <em>block</em> is repeated for <em>name</em> starting at the value of
+the first <em>exp</em>, until it passes the second <em>exp</em> by steps of the
+third <em>exp</em>.
+More precisely, a <b>for</b> statement like
+
+<pre>
+     for v = <em>e1</em>, <em>e2</em>, <em>e3</em> do <em>block</em> end
+</pre><p>
+is equivalent to the code:
+
+<pre>
+     do
+       local <em>var</em>, <em>limit</em>, <em>step</em> = tonumber(<em>e1</em>), tonumber(<em>e2</em>), tonumber(<em>e3</em>)
+       if not (<em>var</em> and <em>limit</em> and <em>step</em>) then error() end
+       <em>var</em> = <em>var</em> - <em>step</em>
+       while true do
+         <em>var</em> = <em>var</em> + <em>step</em>
+         if (<em>step</em> &gt;= 0 and <em>var</em> &gt; <em>limit</em>) or (<em>step</em> &lt; 0 and <em>var</em> &lt; <em>limit</em>) then
+           break
+         end
+         local v = <em>var</em>
+         <em>block</em>
+       end
+     end
+</pre>
+
+<p>
+Note the following:
+
+<ul>
+
+<li>
+All three control expressions are evaluated only once,
+before the loop starts.
+They must all result in numbers.
+</li>
+
+<li>
+<code><em>var</em></code>, <code><em>limit</em></code>, and <code><em>step</em></code> are invisible variables.
+The names shown here are for explanatory purposes only.
+</li>
+
+<li>
+If the third expression (the step) is absent,
+then a step of&nbsp;1 is used.
+</li>
+
+<li>
+You can use <b>break</b> and <b>goto</b> to exit a <b>for</b> loop.
+</li>
+
+<li>
+The loop variable <code>v</code> is local to the loop body.
+If you need its value after the loop,
+assign it to another variable before exiting the loop.
+</li>
+
+</ul>
+
+<p>
+The generic <b>for</b> statement works over functions,
+called <em>iterators</em>.
+On each iteration, the iterator function is called to produce a new value,
+stopping when this new value is <b>nil</b>.
+The generic <b>for</b> loop has the following syntax:
+
+<pre>
+	stat ::= <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b>
+	namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
+</pre><p>
+A <b>for</b> statement like
+
+<pre>
+     for <em>var_1</em>, &middot;&middot;&middot;, <em>var_n</em> in <em>explist</em> do <em>block</em> end
+</pre><p>
+is equivalent to the code:
+
+<pre>
+     do
+       local <em>f</em>, <em>s</em>, <em>var</em> = <em>explist</em>
+       while true do
+         local <em>var_1</em>, &middot;&middot;&middot;, <em>var_n</em> = <em>f</em>(<em>s</em>, <em>var</em>)
+         if <em>var_1</em> == nil then break end
+         <em>var</em> = <em>var_1</em>
+         <em>block</em>
+       end
+     end
+</pre><p>
+Note the following:
+
+<ul>
+
+<li>
+<code><em>explist</em></code> is evaluated only once.
+Its results are an <em>iterator</em> function,
+a <em>state</em>,
+and an initial value for the first <em>iterator variable</em>.
+</li>
+
+<li>
+<code><em>f</em></code>, <code><em>s</em></code>, and <code><em>var</em></code> are invisible variables.
+The names are here for explanatory purposes only.
+</li>
+
+<li>
+You can use <b>break</b> to exit a <b>for</b> loop.
+</li>
+
+<li>
+The loop variables <code><em>var_i</em></code> are local to the loop;
+you cannot use their values after the <b>for</b> ends.
+If you need these values,
+then assign them to other variables before breaking or exiting the loop.
+</li>
+
+</ul>
+
+
+
+
+<h3>3.3.6 &ndash; <a name="3.3.6">Function Calls as Statements</a></h3><p>
+To allow possible side-effects,
+function calls can be executed as statements:
+
+<pre>
+	stat ::= functioncall
+</pre><p>
+In this case, all returned values are thrown away.
+Function calls are explained in <a href="#3.4.10">&sect;3.4.10</a>.
+
+
+
+
+
+<h3>3.3.7 &ndash; <a name="3.3.7">Local Declarations</a></h3><p>
+Local variables can be declared anywhere inside a block.
+The declaration can include an initial assignment:
+
+<pre>
+	stat ::= <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
+</pre><p>
+If present, an initial assignment has the same semantics
+of a multiple assignment (see <a href="#3.3.3">&sect;3.3.3</a>).
+Otherwise, all variables are initialized with <b>nil</b>.
+
+
+<p>
+A chunk is also a block (see <a href="#3.3.2">&sect;3.3.2</a>),
+and so local variables can be declared in a chunk outside any explicit block.
+
+
+<p>
+The visibility rules for local variables are explained in <a href="#3.5">&sect;3.5</a>.
+
+
+
+
+
+
+
+<h2>3.4 &ndash; <a name="3.4">Expressions</a></h2>
+
+<p>
+The basic expressions in Lua are the following:
+
+<pre>
+	exp ::= prefixexp
+	exp ::= <b>nil</b> | <b>false</b> | <b>true</b>
+	exp ::= Numeral
+	exp ::= LiteralString
+	exp ::= functiondef
+	exp ::= tableconstructor
+	exp ::= &lsquo;<b>...</b>&rsquo;
+	exp ::= exp binop exp
+	exp ::= unop exp
+	prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
+</pre>
+
+<p>
+Numerals and literal strings are explained in <a href="#3.1">&sect;3.1</a>;
+variables are explained in <a href="#3.2">&sect;3.2</a>;
+function definitions are explained in <a href="#3.4.11">&sect;3.4.11</a>;
+function calls are explained in <a href="#3.4.10">&sect;3.4.10</a>;
+table constructors are explained in <a href="#3.4.9">&sect;3.4.9</a>.
+Vararg expressions,
+denoted by three dots ('<code>...</code>'), can only be used when
+directly inside a vararg function;
+they are explained in <a href="#3.4.11">&sect;3.4.11</a>.
+
+
+<p>
+Binary operators comprise arithmetic operators (see <a href="#3.4.1">&sect;3.4.1</a>),
+bitwise operators (see <a href="#3.4.2">&sect;3.4.2</a>),
+relational operators (see <a href="#3.4.4">&sect;3.4.4</a>), logical operators (see <a href="#3.4.5">&sect;3.4.5</a>),
+and the concatenation operator (see <a href="#3.4.6">&sect;3.4.6</a>).
+Unary operators comprise the unary minus (see <a href="#3.4.1">&sect;3.4.1</a>),
+the unary bitwise NOT (see <a href="#3.4.2">&sect;3.4.2</a>),
+the unary logical <b>not</b> (see <a href="#3.4.5">&sect;3.4.5</a>),
+and the unary <em>length operator</em> (see <a href="#3.4.7">&sect;3.4.7</a>).
+
+
+<p>
+Both function calls and vararg expressions can result in multiple values.
+If a function call is used as a statement (see <a href="#3.3.6">&sect;3.3.6</a>),
+then its return list is adjusted to zero elements,
+thus discarding all returned values.
+If an expression is used as the last (or the only) element
+of a list of expressions,
+then no adjustment is made
+(unless the expression is enclosed in parentheses).
+In all other contexts,
+Lua adjusts the result list to one element,
+either discarding all values except the first one
+or adding a single <b>nil</b> if there are no values.
+
+
+<p>
+Here are some examples:
+
+<pre>
+     f()                -- adjusted to 0 results
+     g(f(), x)          -- f() is adjusted to 1 result
+     g(x, f())          -- g gets x plus all results from f()
+     a,b,c = f(), x     -- f() is adjusted to 1 result (c gets nil)
+     a,b = ...          -- a gets the first vararg parameter, b gets
+                        -- the second (both a and b can get nil if there
+                        -- is no corresponding vararg parameter)
+     
+     a,b,c = x, f()     -- f() is adjusted to 2 results
+     a,b,c = f()        -- f() is adjusted to 3 results
+     return f()         -- returns all results from f()
+     return ...         -- returns all received vararg parameters
+     return x,y,f()     -- returns x, y, and all results from f()
+     {f()}              -- creates a list with all results from f()
+     {...}              -- creates a list with all vararg parameters
+     {f(), nil}         -- f() is adjusted to 1 result
+</pre>
+
+<p>
+Any expression enclosed in parentheses always results in only one value.
+Thus,
+<code>(f(x,y,z))</code> is always a single value,
+even if <code>f</code> returns several values.
+(The value of <code>(f(x,y,z))</code> is the first value returned by <code>f</code>
+or <b>nil</b> if <code>f</code> does not return any values.)
+
+
+
+<h3>3.4.1 &ndash; <a name="3.4.1">Arithmetic Operators</a></h3><p>
+Lua supports the following arithmetic operators:
+
+<ul>
+<li><b><code>+</code>: </b>addition</li>
+<li><b><code>-</code>: </b>subtraction</li>
+<li><b><code>*</code>: </b>multiplication</li>
+<li><b><code>/</code>: </b>float division</li>
+<li><b><code>//</code>: </b>floor division</li>
+<li><b><code>%</code>: </b>modulo</li>
+<li><b><code>^</code>: </b>exponentiation</li>
+<li><b><code>-</code>: </b>unary minus</li>
+</ul>
+
+<p>
+With the exception of exponentiation and float division,
+the arithmetic operators work as follows:
+If both operands are integers,
+the operation is performed over integers and the result is an integer.
+Otherwise, if both operands are numbers
+or strings that can be converted to
+numbers (see <a href="#3.4.3">&sect;3.4.3</a>),
+then they are converted to floats,
+the operation is performed following the usual rules
+for floating-point arithmetic
+(usually the IEEE 754 standard),
+and the result is a float.
+
+
+<p>
+Exponentiation and float division (<code>/</code>)
+always convert their operands to floats
+and the result is always a float.
+Exponentiation uses the ISO&nbsp;C function <code>pow</code>,
+so that it works for non-integer exponents too.
+
+
+<p>
+Floor division (<code>//</code>) is a division 
+that rounds the quotient towards minus infinity,
+that is, the floor of the division of its operands.
+
+
+<p>
+Modulo is defined as the remainder of a division
+that rounds the quotient towards minus infinity (floor division).
+
+
+<p>
+In case of overflows in integer arithmetic,
+all operations <em>wrap around</em>,
+according to the usual rules of two-complement arithmetic.
+(In other words,
+they return the unique representable integer
+that is equal modulo <em>2<sup>64</sup></em> to the mathematical result.)
+
+
+
+<h3>3.4.2 &ndash; <a name="3.4.2">Bitwise Operators</a></h3><p>
+Lua supports the following bitwise operators:
+
+<ul>
+<li><b><code>&amp;</code>: </b>bitwise AND</li>
+<li><b><code>&#124;</code>: </b>bitwise OR</li>
+<li><b><code>~</code>: </b>bitwise exclusive OR</li>
+<li><b><code>&gt;&gt;</code>: </b>right shift</li>
+<li><b><code>&lt;&lt;</code>: </b>left shift</li>
+<li><b><code>~</code>: </b>unary bitwise NOT</li>
+</ul>
+
+<p>
+All bitwise operations convert its operands to integers
+(see <a href="#3.4.3">&sect;3.4.3</a>),
+operate on all bits of those integers,
+and result in an integer.
+
+
+<p>
+Both right and left shifts fill the vacant bits with zeros.
+Negative displacements shift to the other direction;
+displacements with absolute values equal to or higher than
+the number of bits in an integer
+result in zero (as all bits are shifted out).
+
+
+
+
+
+<h3>3.4.3 &ndash; <a name="3.4.3">Coercions and Conversions</a></h3><p>
+Lua provides some automatic conversions between some
+types and representations at run time.
+Bitwise operators always convert float operands to integers.
+Exponentiation and float division
+always convert integer operands to floats.
+All other arithmetic operations applied to mixed numbers
+(integers and floats) convert the integer operand to a float;
+this is called the <em>usual rule</em>.
+The C API also converts both integers to floats and
+floats to integers, as needed.
+Moreover, string concatenation accepts numbers as arguments,
+besides strings. 
+
+
+<p>
+Lua also converts strings to numbers,
+whenever a number is expected.
+
+
+<p>
+In a conversion from integer to float,
+if the integer value has an exact representation as a float,
+that is the result.
+Otherwise,
+the conversion gets the nearest higher or
+the nearest lower representable value.
+This kind of conversion never fails.
+
+
+<p>
+The conversion from float to integer
+checks whether the float has an exact representation as an integer
+(that is, the float has an integral value and
+it is in the range of integer representation).
+If it does, that representation is the result.
+Otherwise, the conversion fails.
+
+
+<p>
+The conversion from strings to numbers goes as follows:
+First, the string is converted to an integer or a float,
+following its syntax and the rules of the Lua lexer.
+(The string may have also leading and trailing spaces and a sign.)
+Then, the resulting number (float or integer)
+is converted to the type (float or integer) required by the context
+(e.g., the operation that forced the conversion).
+
+
+<p>
+All conversions from strings to numbers 
+accept both a dot and the current locale mark
+as the radix character.
+(The Lua lexer, however, accepts only a dot.)
+
+
+<p>
+The conversion from numbers to strings uses a
+non-specified human-readable format.
+For complete control over how numbers are converted to strings,
+use the <code>format</code> function from the string library
+(see <a href="#pdf-string.format"><code>string.format</code></a>).
+
+
+
+
+
+<h3>3.4.4 &ndash; <a name="3.4.4">Relational Operators</a></h3><p>
+Lua supports the following relational operators:
+
+<ul>
+<li><b><code>==</code>: </b>equality</li>
+<li><b><code>~=</code>: </b>inequality</li>
+<li><b><code>&lt;</code>: </b>less than</li>
+<li><b><code>&gt;</code>: </b>greater than</li>
+<li><b><code>&lt;=</code>: </b>less or equal</li>
+<li><b><code>&gt;=</code>: </b>greater or equal</li>
+</ul><p>
+These operators always result in <b>false</b> or <b>true</b>.
+
+
+<p>
+Equality (<code>==</code>) first compares the type of its operands.
+If the types are different, then the result is <b>false</b>.
+Otherwise, the values of the operands are compared.
+Strings are compared in the obvious way.
+Numbers are equal if they denote the same mathematical value.
+
+
+<p>
+Tables, userdata, and threads
+are compared by reference:
+two objects are considered equal only if they are the same object.
+Every time you create a new object
+(a table, userdata, or thread),
+this new object is different from any previously existing object.
+Closures with the same reference are always equal.
+Closures with any detectable difference
+(different behavior, different definition) are always different.
+
+
+<p>
+You can change the way that Lua compares tables and userdata
+by using the "eq" metamethod (see <a href="#2.4">&sect;2.4</a>).
+
+
+<p>
+Equality comparisons do not convert strings to numbers
+or vice versa.
+Thus, <code>"0"==0</code> evaluates to <b>false</b>,
+and <code>t[0]</code> and <code>t["0"]</code> denote different
+entries in a table.
+
+
+<p>
+The operator <code>~=</code> is exactly the negation of equality (<code>==</code>).
+
+
+<p>
+The order operators work as follows.
+If both arguments are numbers,
+then they are compared according to their mathematical values
+(regardless of their subtypes).
+Otherwise, if both arguments are strings,
+then their values are compared according to the current locale.
+Otherwise, Lua tries to call the "lt" or the "le"
+metamethod (see <a href="#2.4">&sect;2.4</a>).
+A comparison <code>a &gt; b</code> is translated to <code>b &lt; a</code>
+and <code>a &gt;= b</code> is translated to <code>b &lt;= a</code>.
+
+
+<p>
+Following the IEEE 754 standard,
+NaN is considered neither smaller than,
+nor equal to, nor greater than any value (including itself).
+
+
+
+
+
+<h3>3.4.5 &ndash; <a name="3.4.5">Logical Operators</a></h3><p>
+The logical operators in Lua are
+<b>and</b>, <b>or</b>, and <b>not</b>.
+Like the control structures (see <a href="#3.3.4">&sect;3.3.4</a>),
+all logical operators consider both <b>false</b> and <b>nil</b> as false
+and anything else as true.
+
+
+<p>
+The negation operator <b>not</b> always returns <b>false</b> or <b>true</b>.
+The conjunction operator <b>and</b> returns its first argument
+if this value is <b>false</b> or <b>nil</b>;
+otherwise, <b>and</b> returns its second argument.
+The disjunction operator <b>or</b> returns its first argument
+if this value is different from <b>nil</b> and <b>false</b>;
+otherwise, <b>or</b> returns its second argument.
+Both <b>and</b> and <b>or</b> use short-circuit evaluation;
+that is,
+the second operand is evaluated only if necessary.
+Here are some examples:
+
+<pre>
+     10 or 20            --&gt; 10
+     10 or error()       --&gt; 10
+     nil or "a"          --&gt; "a"
+     nil and 10          --&gt; nil
+     false and error()   --&gt; false
+     false and nil       --&gt; false
+     false or nil        --&gt; nil
+     10 and 20           --&gt; 20
+</pre><p>
+(In this manual,
+<code>--&gt;</code> indicates the result of the preceding expression.)
+
+
+
+
+
+<h3>3.4.6 &ndash; <a name="3.4.6">Concatenation</a></h3><p>
+The string concatenation operator in Lua is
+denoted by two dots ('<code>..</code>').
+If both operands are strings or numbers, then they are converted to
+strings according to the rules described in <a href="#3.4.3">&sect;3.4.3</a>.
+Otherwise, the <code>__concat</code> metamethod is called (see <a href="#2.4">&sect;2.4</a>).
+
+
+
+
+
+<h3>3.4.7 &ndash; <a name="3.4.7">The Length Operator</a></h3>
+
+<p>
+The length operator is denoted by the unary prefix operator <code>#</code>.
+The length of a string is its number of bytes
+(that is, the usual meaning of string length when each
+character is one byte).
+
+
+<p>
+A program can modify the behavior of the length operator for
+any value but strings through the <code>__len</code> metamethod (see <a href="#2.4">&sect;2.4</a>).
+
+
+<p>
+Unless a <code>__len</code> metamethod is given,
+the length of a table <code>t</code> is only defined if the
+table is a <em>sequence</em>,
+that is,
+the set of its positive numeric keys is equal to <em>{1..n}</em>
+for some non-negative integer <em>n</em>.
+In that case, <em>n</em> is its length.
+Note that a table like
+
+<pre>
+     {10, 20, nil, 40}
+</pre><p>
+is not a sequence, because it has the key <code>4</code>
+but does not have the key <code>3</code>.
+(So, there is no <em>n</em> such that the set <em>{1..n}</em> is equal
+to the set of positive numeric keys of that table.)
+Note, however, that non-numeric keys do not interfere
+with whether a table is a sequence.
+
+
+
+
+
+<h3>3.4.8 &ndash; <a name="3.4.8">Precedence</a></h3><p>
+Operator precedence in Lua follows the table below,
+from lower to higher priority:
+
+<pre>
+     or
+     and
+     &lt;     &gt;     &lt;=    &gt;=    ~=    ==
+     |
+     ~
+     &amp;
+     &lt;&lt;    &gt;&gt;
+     ..
+     +     -
+     *     /     //    %
+     unary operators (not   #     -     ~)
+     ^
+</pre><p>
+As usual,
+you can use parentheses to change the precedences of an expression.
+The concatenation ('<code>..</code>') and exponentiation ('<code>^</code>')
+operators are right associative.
+All other binary operators are left associative.
+
+
+
+
+
+<h3>3.4.9 &ndash; <a name="3.4.9">Table Constructors</a></h3><p>
+Table constructors are expressions that create tables.
+Every time a constructor is evaluated, a new table is created.
+A constructor can be used to create an empty table
+or to create a table and initialize some of its fields.
+The general syntax for constructors is
+
+<pre>
+	tableconstructor ::= &lsquo;<b>{</b>&rsquo; [fieldlist] &lsquo;<b>}</b>&rsquo;
+	fieldlist ::= field {fieldsep field} [fieldsep]
+	field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
+	fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
+</pre>
+
+<p>
+Each field of the form <code>[exp1] = exp2</code> adds to the new table an entry
+with key <code>exp1</code> and value <code>exp2</code>.
+A field of the form <code>name = exp</code> is equivalent to
+<code>["name"] = exp</code>.
+Finally, fields of the form <code>exp</code> are equivalent to
+<code>[i] = exp</code>, where <code>i</code> are consecutive integers
+starting with 1.
+Fields in the other formats do not affect this counting.
+For example,
+
+<pre>
+     a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
+</pre><p>
+is equivalent to
+
+<pre>
+     do
+       local t = {}
+       t[f(1)] = g
+       t[1] = "x"         -- 1st exp
+       t[2] = "y"         -- 2nd exp
+       t.x = 1            -- t["x"] = 1
+       t[3] = f(x)        -- 3rd exp
+       t[30] = 23
+       t[4] = 45          -- 4th exp
+       a = t
+     end
+</pre>
+
+<p>
+The order of the assignments in a constructor is undefined.
+(This order would be relevant only when there are repeated keys.)
+
+
+<p>
+If the last field in the list has the form <code>exp</code>
+and the expression is a function call or a vararg expression,
+then all values returned by this expression enter the list consecutively
+(see <a href="#3.4.10">&sect;3.4.10</a>).
+
+
+<p>
+The field list can have an optional trailing separator,
+as a convenience for machine-generated code.
+
+
+
+
+
+<h3>3.4.10 &ndash; <a name="3.4.10">Function Calls</a></h3><p>
+A function call in Lua has the following syntax:
+
+<pre>
+	functioncall ::= prefixexp args
+</pre><p>
+In a function call,
+first prefixexp and args are evaluated.
+If the value of prefixexp has type <em>function</em>,
+then this function is called
+with the given arguments.
+Otherwise, the prefixexp "call" metamethod is called,
+having as first parameter the value of prefixexp,
+followed by the original call arguments
+(see <a href="#2.4">&sect;2.4</a>).
+
+
+<p>
+The form
+
+<pre>
+	functioncall ::= prefixexp &lsquo;<b>:</b>&rsquo; Name args
+</pre><p>
+can be used to call "methods".
+A call <code>v:name(<em>args</em>)</code>
+is syntactic sugar for <code>v.name(v,<em>args</em>)</code>,
+except that <code>v</code> is evaluated only once.
+
+
+<p>
+Arguments have the following syntax:
+
+<pre>
+	args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo;
+	args ::= tableconstructor
+	args ::= LiteralString
+</pre><p>
+All argument expressions are evaluated before the call.
+A call of the form <code>f{<em>fields</em>}</code> is
+syntactic sugar for <code>f({<em>fields</em>})</code>;
+that is, the argument list is a single new table.
+A call of the form <code>f'<em>string</em>'</code>
+(or <code>f"<em>string</em>"</code> or <code>f[[<em>string</em>]]</code>)
+is syntactic sugar for <code>f('<em>string</em>')</code>;
+that is, the argument list is a single literal string.
+
+
+<p>
+A call of the form <code>return <em>functioncall</em></code> is called
+a <em>tail call</em>.
+Lua implements <em>proper tail calls</em>
+(or <em>proper tail recursion</em>):
+in a tail call,
+the called function reuses the stack entry of the calling function.
+Therefore, there is no limit on the number of nested tail calls that
+a program can execute.
+However, a tail call erases any debug information about the
+calling function.
+Note that a tail call only happens with a particular syntax,
+where the <b>return</b> has one single function call as argument;
+this syntax makes the calling function return exactly
+the returns of the called function.
+So, none of the following examples are tail calls:
+
+<pre>
+     return (f(x))        -- results adjusted to 1
+     return 2 * f(x)
+     return x, f(x)       -- additional results
+     f(x); return         -- results discarded
+     return x or f(x)     -- results adjusted to 1
+</pre>
+
+
+
+
+<h3>3.4.11 &ndash; <a name="3.4.11">Function Definitions</a></h3>
+
+<p>
+The syntax for function definition is
+
+<pre>
+	functiondef ::= <b>function</b> funcbody
+	funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
+</pre>
+
+<p>
+The following syntactic sugar simplifies function definitions:
+
+<pre>
+	stat ::= <b>function</b> funcname funcbody
+	stat ::= <b>local</b> <b>function</b> Name funcbody
+	funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
+</pre><p>
+The statement
+
+<pre>
+     function f () <em>body</em> end
+</pre><p>
+translates to
+
+<pre>
+     f = function () <em>body</em> end
+</pre><p>
+The statement
+
+<pre>
+     function t.a.b.c.f () <em>body</em> end
+</pre><p>
+translates to
+
+<pre>
+     t.a.b.c.f = function () <em>body</em> end
+</pre><p>
+The statement
+
+<pre>
+     local function f () <em>body</em> end
+</pre><p>
+translates to
+
+<pre>
+     local f; f = function () <em>body</em> end
+</pre><p>
+not to
+
+<pre>
+     local f = function () <em>body</em> end
+</pre><p>
+(This only makes a difference when the body of the function
+contains references to <code>f</code>.)
+
+
+<p>
+A function definition is an executable expression,
+whose value has type <em>function</em>.
+When Lua precompiles a chunk,
+all its function bodies are precompiled too.
+Then, whenever Lua executes the function definition,
+the function is <em>instantiated</em> (or <em>closed</em>).
+This function instance (or <em>closure</em>)
+is the final value of the expression.
+
+
+<p>
+Parameters act as local variables that are
+initialized with the argument values:
+
+<pre>
+	parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
+</pre><p>
+When a function is called,
+the list of arguments is adjusted to
+the length of the list of parameters,
+unless the function is a <em>vararg function</em>,
+which is indicated by three dots ('<code>...</code>')
+at the end of its parameter list.
+A vararg function does not adjust its argument list;
+instead, it collects all extra arguments and supplies them
+to the function through a <em>vararg expression</em>,
+which is also written as three dots.
+The value of this expression is a list of all actual extra arguments,
+similar to a function with multiple results.
+If a vararg expression is used inside another expression
+or in the middle of a list of expressions,
+then its return list is adjusted to one element.
+If the expression is used as the last element of a list of expressions,
+then no adjustment is made
+(unless that last expression is enclosed in parentheses).
+
+
+<p>
+As an example, consider the following definitions:
+
+<pre>
+     function f(a, b) end
+     function g(a, b, ...) end
+     function r() return 1,2,3 end
+</pre><p>
+Then, we have the following mapping from arguments to parameters and
+to the vararg expression:
+
+<pre>
+     CALL            PARAMETERS
+     
+     f(3)             a=3, b=nil
+     f(3, 4)          a=3, b=4
+     f(3, 4, 5)       a=3, b=4
+     f(r(), 10)       a=1, b=10
+     f(r())           a=1, b=2
+     
+     g(3)             a=3, b=nil, ... --&gt;  (nothing)
+     g(3, 4)          a=3, b=4,   ... --&gt;  (nothing)
+     g(3, 4, 5, 8)    a=3, b=4,   ... --&gt;  5  8
+     g(5, r())        a=5, b=1,   ... --&gt;  2  3
+</pre>
+
+<p>
+Results are returned using the <b>return</b> statement (see <a href="#3.3.4">&sect;3.3.4</a>).
+If control reaches the end of a function
+without encountering a <b>return</b> statement,
+then the function returns with no results.
+
+
+<p>
+
+There is a system-dependent limit on the number of values
+that a function may return.
+This limit is guaranteed to be larger than 1000.
+
+
+<p>
+The <em>colon</em> syntax
+is used for defining <em>methods</em>,
+that is, functions that have an implicit extra parameter <code>self</code>.
+Thus, the statement
+
+<pre>
+     function t.a.b.c:f (<em>params</em>) <em>body</em> end
+</pre><p>
+is syntactic sugar for
+
+<pre>
+     t.a.b.c.f = function (self, <em>params</em>) <em>body</em> end
+</pre>
+
+
+
+
+
+
+<h2>3.5 &ndash; <a name="3.5">Visibility Rules</a></h2>
+
+<p>
+
+Lua is a lexically scoped language.
+The scope of a local variable begins at the first statement after
+its declaration and lasts until the last non-void statement
+of the innermost block that includes the declaration.
+Consider the following example:
+
+<pre>
+     x = 10                -- global variable
+     do                    -- new block
+       local x = x         -- new 'x', with value 10
+       print(x)            --&gt; 10
+       x = x+1
+       do                  -- another block
+         local x = x+1     -- another 'x'
+         print(x)          --&gt; 12
+       end
+       print(x)            --&gt; 11
+     end
+     print(x)              --&gt; 10  (the global one)
+</pre>
+
+<p>
+Notice that, in a declaration like <code>local x = x</code>,
+the new <code>x</code> being declared is not in scope yet,
+and so the second <code>x</code> refers to the outside variable.
+
+
+<p>
+Because of the lexical scoping rules,
+local variables can be freely accessed by functions
+defined inside their scope.
+A local variable used by an inner function is called
+an <em>upvalue</em>, or <em>external local variable</em>,
+inside the inner function.
+
+
+<p>
+Notice that each execution of a <b>local</b> statement
+defines new local variables.
+Consider the following example:
+
+<pre>
+     a = {}
+     local x = 20
+     for i=1,10 do
+       local y = 0
+       a[i] = function () y=y+1; return x+y end
+     end
+</pre><p>
+The loop creates ten closures
+(that is, ten instances of the anonymous function).
+Each of these closures uses a different <code>y</code> variable,
+while all of them share the same <code>x</code>.
+
+
+
+
+
+<h1>4 &ndash; <a name="4">The Application Program Interface</a></h1>
+
+<p>
+
+This section describes the C&nbsp;API for Lua, that is,
+the set of C&nbsp;functions available to the host program to communicate
+with Lua.
+All API functions and related types and constants
+are declared in the header file <a name="pdf-lua.h"><code>lua.h</code></a>.
+
+
+<p>
+Even when we use the term "function",
+any facility in the API may be provided as a macro instead.
+Except where stated otherwise,
+all such macros use each of their arguments exactly once
+(except for the first argument, which is always a Lua state),
+and so do not generate any hidden side-effects.
+
+
+<p>
+As in most C&nbsp;libraries,
+the Lua API functions do not check their arguments for validity or consistency.
+However, you can change this behavior by compiling Lua
+with the macro <a name="pdf-LUA_USE_APICHECK"><code>LUA_USE_APICHECK</code></a> defined.
+
+
+
+<h2>4.1 &ndash; <a name="4.1">The Stack</a></h2>
+
+<p>
+Lua uses a <em>virtual stack</em> to pass values to and from C.
+Each element in this stack represents a Lua value
+(<b>nil</b>, number, string, etc.).
+
+
+<p>
+Whenever Lua calls C, the called function gets a new stack,
+which is independent of previous stacks and of stacks of
+C&nbsp;functions that are still active.
+This stack initially contains any arguments to the C&nbsp;function
+and it is where the C&nbsp;function pushes its results
+to be returned to the caller (see <a href="#lua_CFunction"><code>lua_CFunction</code></a>).
+
+
+<p>
+For convenience,
+most query operations in the API do not follow a strict stack discipline.
+Instead, they can refer to any element in the stack
+by using an <em>index</em>:
+A positive index represents an absolute stack position
+(starting at&nbsp;1);
+a negative index represents an offset relative to the top of the stack.
+More specifically, if the stack has <em>n</em> elements,
+then index&nbsp;1 represents the first element
+(that is, the element that was pushed onto the stack first)
+and
+index&nbsp;<em>n</em> represents the last element;
+index&nbsp;-1 also represents the last element
+(that is, the element at the&nbsp;top)
+and index <em>-n</em> represents the first element.
+
+
+
+
+
+<h2>4.2 &ndash; <a name="4.2">Stack Size</a></h2>
+
+<p>
+When you interact with the Lua API,
+you are responsible for ensuring consistency.
+In particular,
+<em>you are responsible for controlling stack overflow</em>.
+You can use the function <a href="#lua_checkstack"><code>lua_checkstack</code></a>
+to ensure that the stack has enough space for pushing new elements.
+
+
+<p>
+Whenever Lua calls C,
+it ensures that the stack has space for
+at least <a name="pdf-LUA_MINSTACK"><code>LUA_MINSTACK</code></a> extra slots.
+<code>LUA_MINSTACK</code> is defined as 20,
+so that usually you do not have to worry about stack space
+unless your code has loops pushing elements onto the stack.
+
+
+<p>
+When you call a Lua function
+without a fixed number of results (see <a href="#lua_call"><code>lua_call</code></a>),
+Lua ensures that the stack has enough space for all results,
+but it does not ensure any extra space.
+So, before pushing anything in the stack after such a call
+you should use <a href="#lua_checkstack"><code>lua_checkstack</code></a>.
+
+
+
+
+
+<h2>4.3 &ndash; <a name="4.3">Valid and Acceptable Indices</a></h2>
+
+<p>
+Any function in the API that receives stack indices
+works only with <em>valid indices</em> or <em>acceptable indices</em>.
+
+
+<p>
+A <em>valid index</em> is an index that refers to a
+position that stores a modifiable Lua value.
+It comprises stack indices between&nbsp;1 and the stack top
+(<code>1 &le; abs(index) &le; top</code>)
+
+plus <em>pseudo-indices</em>,
+which represent some positions that are accessible to C&nbsp;code
+but that are not in the stack.
+Pseudo-indices are used to access the registry (see <a href="#4.5">&sect;4.5</a>)
+and the upvalues of a C&nbsp;function (see <a href="#4.4">&sect;4.4</a>).
+
+
+<p>
+Functions that do not need a specific mutable position,
+but only a value (e.g., query functions),
+can be called with acceptable indices.
+An <em>acceptable index</em> can be any valid index,
+but it also can be any positive index after the stack top
+within the space allocated for the stack,
+that is, indices up to the stack size.
+(Note that 0 is never an acceptable index.)
+Except when noted otherwise,
+functions in the API work with acceptable indices.
+
+
+<p>
+Acceptable indices serve to avoid extra tests
+against the stack top when querying the stack.
+For instance, a C&nbsp;function can query its third argument
+without the need to first check whether there is a third argument,
+that is, without the need to check whether 3 is a valid index.
+
+
+<p>
+For functions that can be called with acceptable indices,
+any non-valid index is treated as if it
+contains a value of a virtual type <a name="pdf-LUA_TNONE"><code>LUA_TNONE</code></a>,
+which behaves like a nil value.
+
+
+
+
+
+<h2>4.4 &ndash; <a name="4.4">C Closures</a></h2>
+
+<p>
+When a C&nbsp;function is created,
+it is possible to associate some values with it,
+thus creating a <em>C&nbsp;closure</em>
+(see <a href="#lua_pushcclosure"><code>lua_pushcclosure</code></a>);
+these values are called <em>upvalues</em> and are
+accessible to the function whenever it is called.
+
+
+<p>
+Whenever a C&nbsp;function is called,
+its upvalues are located at specific pseudo-indices.
+These pseudo-indices are produced by the macro
+<a href="#lua_upvalueindex"><code>lua_upvalueindex</code></a>.
+The first upvalue associated with a function is at index
+<code>lua_upvalueindex(1)</code>, and so on.
+Any access to <code>lua_upvalueindex(<em>n</em>)</code>,
+where <em>n</em> is greater than the number of upvalues of the
+current function
+(but not greater than 256,
+which is one plus the maximum number of upvalues in a closure),
+produces an acceptable but invalid index.
+
+
+
+
+
+<h2>4.5 &ndash; <a name="4.5">Registry</a></h2>
+
+<p>
+Lua provides a <em>registry</em>,
+a predefined table that can be used by any C&nbsp;code to
+store whatever Lua values it needs to store.
+The registry table is always located at pseudo-index
+<a name="pdf-LUA_REGISTRYINDEX"><code>LUA_REGISTRYINDEX</code></a>.
+Any C&nbsp;library can store data into this table,
+but it must take care to choose keys
+that are different from those used
+by other libraries, to avoid collisions.
+Typically, you should use as key a string containing your library name,
+or a light userdata with the address of a C&nbsp;object in your code,
+or any Lua object created by your code.
+As with variable names,
+string keys starting with an underscore followed by
+uppercase letters are reserved for Lua.
+
+
+<p>
+The integer keys in the registry are used
+by the reference mechanism (see <a href="#luaL_ref"><code>luaL_ref</code></a>)
+and by some predefined values.
+Therefore, integer keys must not be used for other purposes.
+
+
+<p>
+When you create a new Lua state,
+its registry comes with some predefined values.
+These predefined values are indexed with integer keys
+defined as constants in <code>lua.h</code>.
+The following constants are defined:
+
+<ul>
+<li><b><a name="pdf-LUA_RIDX_MAINTHREAD"><code>LUA_RIDX_MAINTHREAD</code></a>: </b> At this index the registry has
+the main thread of the state.
+(The main thread is the one created together with the state.)
+</li>
+
+<li><b><a name="pdf-LUA_RIDX_GLOBALS"><code>LUA_RIDX_GLOBALS</code></a>: </b> At this index the registry has
+the global environment.
+</li>
+</ul>
+
+
+
+
+<h2>4.6 &ndash; <a name="4.6">Error Handling in C</a></h2>
+
+<p>
+Internally, Lua uses the C <code>longjmp</code> facility to handle errors.
+(Lua will use exceptions if you compile it as C++;
+search for <code>LUAI_THROW</code> in the source code for details.)
+When Lua faces any error
+(such as a memory allocation error, type errors, syntax errors,
+and runtime errors)
+it <em>raises</em> an error;
+that is, it does a long jump.
+A <em>protected environment</em> uses <code>setjmp</code>
+to set a recovery point;
+any error jumps to the most recent active recovery point.
+
+
+<p>
+If an error happens outside any protected environment,
+Lua calls a <em>panic function</em> (see <a href="#lua_atpanic"><code>lua_atpanic</code></a>)
+and then calls <code>abort</code>,
+thus exiting the host application.
+Your panic function can avoid this exit by
+never returning
+(e.g., doing a long jump to your own recovery point outside Lua).
+
+
+<p>
+The panic function runs as if it were a message handler (see <a href="#2.3">&sect;2.3</a>);
+in particular, the error object is at the top of the stack.
+However, there is no guarantee about stack space.
+To push anything on the stack,
+the panic function must first check the available space (see <a href="#4.2">&sect;4.2</a>).
+
+
+<p>
+Most functions in the API can raise an error,
+for instance due to a memory allocation error.
+The documentation for each function indicates whether
+it can raise errors.
+
+
+<p>
+Inside a C&nbsp;function you can raise an error by calling <a href="#lua_error"><code>lua_error</code></a>.
+
+
+
+
+
+<h2>4.7 &ndash; <a name="4.7">Handling Yields in C</a></h2>
+
+<p>
+Internally, Lua uses the C <code>longjmp</code> facility to yield a coroutine.
+Therefore, if a C function <code>foo</code> calls an API function
+and this API function yields
+(directly or indirectly by calling another function that yields),
+Lua cannot return to <code>foo</code> any more,
+because the <code>longjmp</code> removes its frame from the C stack.
+
+
+<p>
+To avoid this kind of problem,
+Lua raises an error whenever it tries to yield across an API call,
+except for three functions:
+<a href="#lua_yieldk"><code>lua_yieldk</code></a>, <a href="#lua_callk"><code>lua_callk</code></a>, and <a href="#lua_pcallk"><code>lua_pcallk</code></a>.
+All those functions receive a <em>continuation function</em>
+(as a parameter named <code>k</code>) to continue execution after a yield.
+
+
+<p>
+We need to set some terminology to explain continuations.
+We have a C function called from Lua which we will call
+the <em>original function</em>.
+This original function then calls one of those three functions in the C API,
+which we will call the <em>callee function</em>,
+that then yields the current thread.
+(This can happen when the callee function is <a href="#lua_yieldk"><code>lua_yieldk</code></a>,
+or when the callee function is either <a href="#lua_callk"><code>lua_callk</code></a> or <a href="#lua_pcallk"><code>lua_pcallk</code></a>
+and the function called by them yields.)
+
+
+<p>
+Suppose the running thread yields while executing the callee function.
+After the thread resumes,
+it eventually will finish running the callee function.
+However,
+the callee function cannot return to the original function,
+because its frame in the C stack was destroyed by the yield.
+Instead, Lua calls a <em>continuation function</em>,
+which was given as an argument to the callee function.
+As the name implies,
+the continuation function should continue the task
+of the original function.
+
+
+<p>
+As an illustration, consider the following function:
+
+<pre>
+     int original_function (lua_State *L) {
+       ...     /* code 1 */
+       status = lua_pcall(L, n, m, h);  /* calls Lua */
+       ...     /* code 2 */
+     }
+</pre><p>
+Now we want to allow
+the Lua code being run by <a href="#lua_pcall"><code>lua_pcall</code></a> to yield.
+First, we can rewrite our function like here:
+
+<pre>
+     int k (lua_State *L, int status, lua_KContext ctx) {
+       ...  /* code 2 */
+     }
+     
+     int original_function (lua_State *L) {
+       ...     /* code 1 */
+       return k(L, lua_pcall(L, n, m, h), ctx);
+     }
+</pre><p>
+In the above code,
+the new function <code>k</code> is a
+<em>continuation function</em> (with type <a href="#lua_KFunction"><code>lua_KFunction</code></a>),
+which should do all the work that the original function
+was doing after calling <a href="#lua_pcall"><code>lua_pcall</code></a>.
+Now, we must inform Lua that it must call <code>k</code> if the Lua code
+being executed by <a href="#lua_pcall"><code>lua_pcall</code></a> gets interrupted in some way
+(errors or yielding),
+so we rewrite the code as here,
+replacing <a href="#lua_pcall"><code>lua_pcall</code></a> by <a href="#lua_pcallk"><code>lua_pcallk</code></a>:
+
+<pre>
+     int original_function (lua_State *L) {
+       ...     /* code 1 */
+       return k(L, lua_pcallk(L, n, m, h, ctx2, k), ctx1);
+     }
+</pre><p>
+Note the external, explicit call to the continuation:
+Lua will call the continuation only if needed, that is,
+in case of errors or resuming after a yield.
+If the called function returns normally without ever yielding,
+<a href="#lua_pcallk"><code>lua_pcallk</code></a> (and <a href="#lua_callk"><code>lua_callk</code></a>) will also return normally.
+(Of course, instead of calling the continuation in that case,
+you can do the equivalent work directly inside the original function.)
+
+
+<p>
+Besides the Lua state,
+the continuation function has two other parameters:
+the final status of the call plus the context value (<code>ctx</code>) that
+was passed originally to <a href="#lua_pcallk"><code>lua_pcallk</code></a>.
+(Lua does not use this context value;
+it only passes this value from the original function to the
+continuation function.)
+For <a href="#lua_pcallk"><code>lua_pcallk</code></a>,
+the status is the same value that would be returned by <a href="#lua_pcallk"><code>lua_pcallk</code></a>,
+except that it is <a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> when being executed after a yield
+(instead of <a href="#pdf-LUA_OK"><code>LUA_OK</code></a>).
+For <a href="#lua_yieldk"><code>lua_yieldk</code></a> and <a href="#lua_callk"><code>lua_callk</code></a>,
+the status is always <a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> when Lua calls the continuation.
+(For these two functions,
+Lua will not call the continuation in case of errors,
+because they do not handle errors.)
+Similarly, when using <a href="#lua_callk"><code>lua_callk</code></a>,
+you should call the continuation function
+with <a href="#pdf-LUA_OK"><code>LUA_OK</code></a> as the status.
+(For <a href="#lua_yieldk"><code>lua_yieldk</code></a>, there is not much point in calling
+directly the continuation function,
+because <a href="#lua_yieldk"><code>lua_yieldk</code></a> usually does not return.)
+
+
+<p>
+Lua treats the continuation function as if it were the original function.
+The continuation function receives the same Lua stack
+from the original function,
+in the same state it would be if the callee function had returned.
+(For instance,
+after a <a href="#lua_callk"><code>lua_callk</code></a> the function and its arguments are
+removed from the stack and replaced by the results from the call.)
+It also has the same upvalues.
+Whatever it returns is handled by Lua as if it were the return
+of the original function.
+
+
+
+
+
+<h2>4.8 &ndash; <a name="4.8">Functions and Types</a></h2>
+
+<p>
+Here we list all functions and types from the C&nbsp;API in
+alphabetical order.
+Each function has an indicator like this:
+<span class="apii">[-o, +p, <em>x</em>]</span>
+
+
+<p>
+The first field, <code>o</code>,
+is how many elements the function pops from the stack.
+The second field, <code>p</code>,
+is how many elements the function pushes onto the stack.
+(Any function always pushes its results after popping its arguments.)
+A field in the form <code>x|y</code> means the function can push (or pop)
+<code>x</code> or <code>y</code> elements,
+depending on the situation;
+an interrogation mark '<code>?</code>' means that
+we cannot know how many elements the function pops/pushes
+by looking only at its arguments
+(e.g., they may depend on what is on the stack).
+The third field, <code>x</code>,
+tells whether the function may raise errors:
+'<code>-</code>' means the function never raises any error;
+'<code>m</code>' means the function may raise out-of-memory errors
+and errors running a <code>__gc</code> metamethod;
+'<code>e</code>' means the function may raise any errors
+(it can run arbitrary Lua code,
+either directly or through metamethods);
+'<code>v</code>' means the function may raise an error on purpose.
+
+
+
+<hr><h3><a name="lua_absindex"><code>lua_absindex</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_absindex (lua_State *L, int idx);</pre>
+
+<p>
+Converts the acceptable index <code>idx</code>
+into an equivalent absolute index
+(that is, one that does not depend on the stack top).
+
+
+
+
+
+<hr><h3><a name="lua_Alloc"><code>lua_Alloc</code></a></h3>
+<pre>typedef void * (*lua_Alloc) (void *ud,
+                             void *ptr,
+                             size_t osize,
+                             size_t nsize);</pre>
+
+<p>
+The type of the memory-allocation function used by Lua states.
+The allocator function must provide a
+functionality similar to <code>realloc</code>,
+but not exactly the same.
+Its arguments are
+<code>ud</code>, an opaque pointer passed to <a href="#lua_newstate"><code>lua_newstate</code></a>;
+<code>ptr</code>, a pointer to the block being allocated/reallocated/freed;
+<code>osize</code>, the original size of the block or some code about what
+is being allocated;
+and <code>nsize</code>, the new size of the block.
+
+
+<p>
+When <code>ptr</code> is not <code>NULL</code>,
+<code>osize</code> is the size of the block pointed by <code>ptr</code>,
+that is, the size given when it was allocated or reallocated.
+
+
+<p>
+When <code>ptr</code> is <code>NULL</code>,
+<code>osize</code> encodes the kind of object that Lua is allocating.
+<code>osize</code> is any of
+<a href="#pdf-LUA_TSTRING"><code>LUA_TSTRING</code></a>, <a href="#pdf-LUA_TTABLE"><code>LUA_TTABLE</code></a>, <a href="#pdf-LUA_TFUNCTION"><code>LUA_TFUNCTION</code></a>,
+<a href="#pdf-LUA_TUSERDATA"><code>LUA_TUSERDATA</code></a>, or <a href="#pdf-LUA_TTHREAD"><code>LUA_TTHREAD</code></a> when (and only when)
+Lua is creating a new object of that type.
+When <code>osize</code> is some other value,
+Lua is allocating memory for something else.
+
+
+<p>
+Lua assumes the following behavior from the allocator function:
+
+
+<p>
+When <code>nsize</code> is zero,
+the allocator must behave like <code>free</code>
+and return <code>NULL</code>.
+
+
+<p>
+When <code>nsize</code> is not zero,
+the allocator must behave like <code>realloc</code>.
+The allocator returns <code>NULL</code>
+if and only if it cannot fulfill the request.
+Lua assumes that the allocator never fails when
+<code>osize &gt;= nsize</code>.
+
+
+<p>
+Here is a simple implementation for the allocator function.
+It is used in the auxiliary library by <a href="#luaL_newstate"><code>luaL_newstate</code></a>.
+
+<pre>
+     static void *l_alloc (void *ud, void *ptr, size_t osize,
+                                                size_t nsize) {
+       (void)ud;  (void)osize;  /* not used */
+       if (nsize == 0) {
+         free(ptr);
+         return NULL;
+       }
+       else
+         return realloc(ptr, nsize);
+     }
+</pre><p>
+Note that Standard&nbsp;C ensures
+that <code>free(NULL)</code> has no effect and that
+<code>realloc(NULL,size)</code> is equivalent to <code>malloc(size)</code>.
+This code assumes that <code>realloc</code> does not fail when shrinking a block.
+(Although Standard&nbsp;C does not ensure this behavior,
+it seems to be a safe assumption.)
+
+
+
+
+
+<hr><h3><a name="lua_arith"><code>lua_arith</code></a></h3><p>
+<span class="apii">[-(2|1), +1, <em>e</em>]</span>
+<pre>void lua_arith (lua_State *L, int op);</pre>
+
+<p>
+Performs an arithmetic or bitwise operation over the two values
+(or one, in the case of negations)
+at the top of the stack,
+with the value at the top being the second operand,
+pops these values, and pushes the result of the operation.
+The function follows the semantics of the corresponding Lua operator
+(that is, it may call metamethods).
+
+
+<p>
+The value of <code>op</code> must be one of the following constants:
+
+<ul>
+
+<li><b><a name="pdf-LUA_OPADD"><code>LUA_OPADD</code></a>: </b> performs addition (<code>+</code>)</li>
+<li><b><a name="pdf-LUA_OPSUB"><code>LUA_OPSUB</code></a>: </b> performs subtraction (<code>-</code>)</li>
+<li><b><a name="pdf-LUA_OPMUL"><code>LUA_OPMUL</code></a>: </b> performs multiplication (<code>*</code>)</li>
+<li><b><a name="pdf-LUA_OPDIV"><code>LUA_OPDIV</code></a>: </b> performs float division (<code>/</code>)</li>
+<li><b><a name="pdf-LUA_OPIDIV"><code>LUA_OPIDIV</code></a>: </b> performs floor division (<code>//</code>)</li>
+<li><b><a name="pdf-LUA_OPMOD"><code>LUA_OPMOD</code></a>: </b> performs modulo (<code>%</code>)</li>
+<li><b><a name="pdf-LUA_OPPOW"><code>LUA_OPPOW</code></a>: </b> performs exponentiation (<code>^</code>)</li>
+<li><b><a name="pdf-LUA_OPUNM"><code>LUA_OPUNM</code></a>: </b> performs mathematical negation (unary <code>-</code>)</li>
+<li><b><a name="pdf-LUA_OPBNOT"><code>LUA_OPBNOT</code></a>: </b> performs bitwise NOT (<code>~</code>)</li>
+<li><b><a name="pdf-LUA_OPBAND"><code>LUA_OPBAND</code></a>: </b> performs bitwise AND (<code>&amp;</code>)</li>
+<li><b><a name="pdf-LUA_OPBOR"><code>LUA_OPBOR</code></a>: </b> performs bitwise OR (<code>|</code>)</li>
+<li><b><a name="pdf-LUA_OPBXOR"><code>LUA_OPBXOR</code></a>: </b> performs bitwise exclusive OR (<code>~</code>)</li>
+<li><b><a name="pdf-LUA_OPSHL"><code>LUA_OPSHL</code></a>: </b> performs left shift (<code>&lt;&lt;</code>)</li>
+<li><b><a name="pdf-LUA_OPSHR"><code>LUA_OPSHR</code></a>: </b> performs right shift (<code>&gt;&gt;</code>)</li>
+
+</ul>
+
+
+
+
+<hr><h3><a name="lua_atpanic"><code>lua_atpanic</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);</pre>
+
+<p>
+Sets a new panic function and returns the old one (see <a href="#4.6">&sect;4.6</a>).
+
+
+
+
+
+<hr><h3><a name="lua_call"><code>lua_call</code></a></h3><p>
+<span class="apii">[-(nargs+1), +nresults, <em>e</em>]</span>
+<pre>void lua_call (lua_State *L, int nargs, int nresults);</pre>
+
+<p>
+Calls a function.
+
+
+<p>
+To call a function you must use the following protocol:
+first, the function to be called is pushed onto the stack;
+then, the arguments to the function are pushed
+in direct order;
+that is, the first argument is pushed first.
+Finally you call <a href="#lua_call"><code>lua_call</code></a>;
+<code>nargs</code> is the number of arguments that you pushed onto the stack.
+All arguments and the function value are popped from the stack
+when the function is called.
+The function results are pushed onto the stack when the function returns.
+The number of results is adjusted to <code>nresults</code>,
+unless <code>nresults</code> is <a name="pdf-LUA_MULTRET"><code>LUA_MULTRET</code></a>.
+In this case, all results from the function are pushed.
+Lua takes care that the returned values fit into the stack space,
+but it does not ensure any extra space in the stack.
+The function results are pushed onto the stack in direct order
+(the first result is pushed first),
+so that after the call the last result is on the top of the stack.
+
+
+<p>
+Any error inside the called function is propagated upwards
+(with a <code>longjmp</code>).
+
+
+<p>
+The following example shows how the host program can do the
+equivalent to this Lua code:
+
+<pre>
+     a = f("how", t.x, 14)
+</pre><p>
+Here it is in&nbsp;C:
+
+<pre>
+     lua_getglobal(L, "f");                  /* function to be called */
+     lua_pushliteral(L, "how");                       /* 1st argument */
+     lua_getglobal(L, "t");                    /* table to be indexed */
+     lua_getfield(L, -1, "x");        /* push result of t.x (2nd arg) */
+     lua_remove(L, -2);                  /* remove 't' from the stack */
+     lua_pushinteger(L, 14);                          /* 3rd argument */
+     lua_call(L, 3, 1);     /* call 'f' with 3 arguments and 1 result */
+     lua_setglobal(L, "a");                         /* set global 'a' */
+</pre><p>
+Note that the code above is <em>balanced</em>:
+at its end, the stack is back to its original configuration.
+This is considered good programming practice.
+
+
+
+
+
+<hr><h3><a name="lua_callk"><code>lua_callk</code></a></h3><p>
+<span class="apii">[-(nargs + 1), +nresults, <em>e</em>]</span>
+<pre>void lua_callk (lua_State *L,
+                int nargs,
+                int nresults,
+                lua_KContext ctx,
+                lua_KFunction k);</pre>
+
+<p>
+This function behaves exactly like <a href="#lua_call"><code>lua_call</code></a>,
+but allows the called function to yield (see <a href="#4.7">&sect;4.7</a>).
+
+
+
+
+
+<hr><h3><a name="lua_CFunction"><code>lua_CFunction</code></a></h3>
+<pre>typedef int (*lua_CFunction) (lua_State *L);</pre>
+
+<p>
+Type for C&nbsp;functions.
+
+
+<p>
+In order to communicate properly with Lua,
+a C&nbsp;function must use the following protocol,
+which defines the way parameters and results are passed:
+a C&nbsp;function receives its arguments from Lua in its stack
+in direct order (the first argument is pushed first).
+So, when the function starts,
+<code>lua_gettop(L)</code> returns the number of arguments received by the function.
+The first argument (if any) is at index 1
+and its last argument is at index <code>lua_gettop(L)</code>.
+To return values to Lua, a C&nbsp;function just pushes them onto the stack,
+in direct order (the first result is pushed first),
+and returns the number of results.
+Any other value in the stack below the results will be properly
+discarded by Lua.
+Like a Lua function, a C&nbsp;function called by Lua can also return
+many results.
+
+
+<p>
+As an example, the following function receives a variable number
+of numeric arguments and returns their average and their sum:
+
+<pre>
+     static int foo (lua_State *L) {
+       int n = lua_gettop(L);    /* number of arguments */
+       lua_Number sum = 0.0;
+       int i;
+       for (i = 1; i &lt;= n; i++) {
+         if (!lua_isnumber(L, i)) {
+           lua_pushliteral(L, "incorrect argument");
+           lua_error(L);
+         }
+         sum += lua_tonumber(L, i);
+       }
+       lua_pushnumber(L, sum/n);        /* first result */
+       lua_pushnumber(L, sum);         /* second result */
+       return 2;                   /* number of results */
+     }
+</pre>
+
+
+
+
+<hr><h3><a name="lua_checkstack"><code>lua_checkstack</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_checkstack (lua_State *L, int n);</pre>
+
+<p>
+Ensures that the stack has space for at least <code>n</code> extra slots
+(that is, that you can safely push up to <code>n</code> values into it).
+It returns false if it cannot fulfill the request,
+either because it would cause the stack
+to be larger than a fixed maximum size
+(typically at least several thousand elements) or
+because it cannot allocate memory for the extra space.
+This function never shrinks the stack;
+if the stack already has space for the extra slots,
+it is left unchanged.
+
+
+
+
+
+<hr><h3><a name="lua_close"><code>lua_close</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void lua_close (lua_State *L);</pre>
+
+<p>
+Destroys all objects in the given Lua state
+(calling the corresponding garbage-collection metamethods, if any)
+and frees all dynamic memory used by this state.
+On several platforms, you may not need to call this function,
+because all resources are naturally released when the host program ends.
+On the other hand, long-running programs that create multiple states,
+such as daemons or web servers,
+will probably need to close states as soon as they are not needed.
+
+
+
+
+
+<hr><h3><a name="lua_compare"><code>lua_compare</code></a></h3><p>
+<span class="apii">[-0, +0, <em>e</em>]</span>
+<pre>int lua_compare (lua_State *L, int index1, int index2, int op);</pre>
+
+<p>
+Compares two Lua values.
+Returns 1 if the value at index <code>index1</code> satisfies <code>op</code>
+when compared with the value at index <code>index2</code>,
+following the semantics of the corresponding Lua operator
+(that is, it may call metamethods).
+Otherwise returns&nbsp;0.
+Also returns&nbsp;0 if any of the indices is not valid.
+
+
+<p>
+The value of <code>op</code> must be one of the following constants:
+
+<ul>
+
+<li><b><a name="pdf-LUA_OPEQ"><code>LUA_OPEQ</code></a>: </b> compares for equality (<code>==</code>)</li>
+<li><b><a name="pdf-LUA_OPLT"><code>LUA_OPLT</code></a>: </b> compares for less than (<code>&lt;</code>)</li>
+<li><b><a name="pdf-LUA_OPLE"><code>LUA_OPLE</code></a>: </b> compares for less or equal (<code>&lt;=</code>)</li>
+
+</ul>
+
+
+
+
+<hr><h3><a name="lua_concat"><code>lua_concat</code></a></h3><p>
+<span class="apii">[-n, +1, <em>e</em>]</span>
+<pre>void lua_concat (lua_State *L, int n);</pre>
+
+<p>
+Concatenates the <code>n</code> values at the top of the stack,
+pops them, and leaves the result at the top.
+If <code>n</code>&nbsp;is&nbsp;1, the result is the single value on the stack
+(that is, the function does nothing);
+if <code>n</code> is 0, the result is the empty string.
+Concatenation is performed following the usual semantics of Lua
+(see <a href="#3.4.6">&sect;3.4.6</a>).
+
+
+
+
+
+<hr><h3><a name="lua_copy"><code>lua_copy</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void lua_copy (lua_State *L, int fromidx, int toidx);</pre>
+
+<p>
+Copies the element at index <code>fromidx</code>
+into the valid index <code>toidx</code>,
+replacing the value at that position.
+Values at other positions are not affected.
+
+
+
+
+
+<hr><h3><a name="lua_createtable"><code>lua_createtable</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void lua_createtable (lua_State *L, int narr, int nrec);</pre>
+
+<p>
+Creates a new empty table and pushes it onto the stack.
+Parameter <code>narr</code> is a hint for how many elements the table
+will have as a sequence;
+parameter <code>nrec</code> is a hint for how many other elements
+the table will have.
+Lua may use these hints to preallocate memory for the new table.
+This preallocation is useful for performance when you know in advance
+how many elements the table will have.
+Otherwise you can use the function <a href="#lua_newtable"><code>lua_newtable</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_dump"><code>lua_dump</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_dump (lua_State *L,
+                        lua_Writer writer,
+                        void *data,
+                        int strip);</pre>
+
+<p>
+Dumps a function as a binary chunk.
+Receives a Lua function on the top of the stack
+and produces a binary chunk that,
+if loaded again,
+results in a function equivalent to the one dumped.
+As it produces parts of the chunk,
+<a href="#lua_dump"><code>lua_dump</code></a> calls function <code>writer</code> (see <a href="#lua_Writer"><code>lua_Writer</code></a>)
+with the given <code>data</code>
+to write them.
+
+
+<p>
+If <code>strip</code> is true,
+the binary representation may not include all debug information
+about the function,
+to save space.
+
+
+<p>
+The value returned is the error code returned by the last
+call to the writer;
+0&nbsp;means no errors.
+
+
+<p>
+This function does not pop the Lua function from the stack.
+
+
+
+
+
+<hr><h3><a name="lua_error"><code>lua_error</code></a></h3><p>
+<span class="apii">[-1, +0, <em>v</em>]</span>
+<pre>int lua_error (lua_State *L);</pre>
+
+<p>
+Generates a Lua error,
+using the value at the top of the stack as the error object.
+This function does a long jump,
+and therefore never returns
+(see <a href="#luaL_error"><code>luaL_error</code></a>).
+
+
+
+
+
+<hr><h3><a name="lua_gc"><code>lua_gc</code></a></h3><p>
+<span class="apii">[-0, +0, <em>m</em>]</span>
+<pre>int lua_gc (lua_State *L, int what, int data);</pre>
+
+<p>
+Controls the garbage collector.
+
+
+<p>
+This function performs several tasks,
+according to the value of the parameter <code>what</code>:
+
+<ul>
+
+<li><b><code>LUA_GCSTOP</code>: </b>
+stops the garbage collector.
+</li>
+
+<li><b><code>LUA_GCRESTART</code>: </b>
+restarts the garbage collector.
+</li>
+
+<li><b><code>LUA_GCCOLLECT</code>: </b>
+performs a full garbage-collection cycle.
+</li>
+
+<li><b><code>LUA_GCCOUNT</code>: </b>
+returns the current amount of memory (in Kbytes) in use by Lua.
+</li>
+
+<li><b><code>LUA_GCCOUNTB</code>: </b>
+returns the remainder of dividing the current amount of bytes of
+memory in use by Lua by 1024.
+</li>
+
+<li><b><code>LUA_GCSTEP</code>: </b>
+performs an incremental step of garbage collection.
+</li>
+
+<li><b><code>LUA_GCSETPAUSE</code>: </b>
+sets <code>data</code> as the new value
+for the <em>pause</em> of the collector (see <a href="#2.5">&sect;2.5</a>)
+and returns the previous value of the pause.
+</li>
+
+<li><b><code>LUA_GCSETSTEPMUL</code>: </b>
+sets <code>data</code> as the new value for the <em>step multiplier</em> of
+the collector (see <a href="#2.5">&sect;2.5</a>)
+and returns the previous value of the step multiplier.
+</li>
+
+<li><b><code>LUA_GCISRUNNING</code>: </b>
+returns a boolean that tells whether the collector is running
+(i.e., not stopped).
+</li>
+
+</ul>
+
+<p>
+For more details about these options,
+see <a href="#pdf-collectgarbage"><code>collectgarbage</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_getallocf"><code>lua_getallocf</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_Alloc lua_getallocf (lua_State *L, void **ud);</pre>
+
+<p>
+Returns the memory-allocation function of a given state.
+If <code>ud</code> is not <code>NULL</code>, Lua stores in <code>*ud</code> the
+opaque pointer given when the memory-allocator function was set.
+
+
+
+
+
+<hr><h3><a name="lua_getfield"><code>lua_getfield</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>int lua_getfield (lua_State *L, int index, const char *k);</pre>
+
+<p>
+Pushes onto the stack the value <code>t[k]</code>,
+where <code>t</code> is the value at the given index.
+As in Lua, this function may trigger a metamethod
+for the "index" event (see <a href="#2.4">&sect;2.4</a>).
+
+
+<p>
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="lua_getextraspace"><code>lua_getextraspace</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void *lua_getextraspace (lua_State *L);</pre>
+
+<p>
+Returns a pointer to a raw memory area associated with the
+given Lua state.
+The application can use this area for any purpose;
+Lua does not use it for anything.
+
+
+<p>
+Each new thread has this area initialized with a copy
+of the area of the main thread.
+
+
+<p>
+By default, this area has the size of a pointer to void,
+but you can recompile Lua with a different size for this area.
+(See <code>LUA_EXTRASPACE</code> in <code>luaconf.h</code>.)
+
+
+
+
+
+<hr><h3><a name="lua_getglobal"><code>lua_getglobal</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>int lua_getglobal (lua_State *L, const char *name);</pre>
+
+<p>
+Pushes onto the stack the value of the global <code>name</code>.
+Returns the type of that value.
+
+
+
+
+
+<hr><h3><a name="lua_geti"><code>lua_geti</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>int lua_geti (lua_State *L, int index, lua_Integer i);</pre>
+
+<p>
+Pushes onto the stack the value <code>t[i]</code>,
+where <code>t</code> is the value at the given index.
+As in Lua, this function may trigger a metamethod
+for the "index" event (see <a href="#2.4">&sect;2.4</a>).
+
+
+<p>
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="lua_getmetatable"><code>lua_getmetatable</code></a></h3><p>
+<span class="apii">[-0, +(0|1), &ndash;]</span>
+<pre>int lua_getmetatable (lua_State *L, int index);</pre>
+
+<p>
+If the value at the given index has a metatable,
+the function pushes that metatable onto the stack and returns&nbsp;1.
+Otherwise,
+the function returns&nbsp;0 and pushes nothing on the stack.
+
+
+
+
+
+<hr><h3><a name="lua_gettable"><code>lua_gettable</code></a></h3><p>
+<span class="apii">[-1, +1, <em>e</em>]</span>
+<pre>int lua_gettable (lua_State *L, int index);</pre>
+
+<p>
+Pushes onto the stack the value <code>t[k]</code>,
+where <code>t</code> is the value at the given index
+and <code>k</code> is the value at the top of the stack.
+
+
+<p>
+This function pops the key from the stack,
+pushing the resulting value in its place.
+As in Lua, this function may trigger a metamethod
+for the "index" event (see <a href="#2.4">&sect;2.4</a>).
+
+
+<p>
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="lua_gettop"><code>lua_gettop</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_gettop (lua_State *L);</pre>
+
+<p>
+Returns the index of the top element in the stack.
+Because indices start at&nbsp;1,
+this result is equal to the number of elements in the stack;
+in particular, 0&nbsp;means an empty stack.
+
+
+
+
+
+<hr><h3><a name="lua_getuservalue"><code>lua_getuservalue</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int lua_getuservalue (lua_State *L, int index);</pre>
+
+<p>
+Pushes onto the stack the Lua value associated with the userdata
+at the given index.
+
+
+<p>
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="lua_insert"><code>lua_insert</code></a></h3><p>
+<span class="apii">[-1, +1, &ndash;]</span>
+<pre>void lua_insert (lua_State *L, int index);</pre>
+
+<p>
+Moves the top element into the given valid index,
+shifting up the elements above this index to open space.
+This function cannot be called with a pseudo-index,
+because a pseudo-index is not an actual stack position.
+
+
+
+
+
+<hr><h3><a name="lua_Integer"><code>lua_Integer</code></a></h3>
+<pre>typedef ... lua_Integer;</pre>
+
+<p>
+The type of integers in Lua.
+
+
+<p>
+By default this type is <code>long long</code>,
+(usually a 64-bit two-complement integer),
+but that can be changed to <code>long</code> or <code>int</code>
+(usually a 32-bit two-complement integer).
+(See <code>LUA_INT_TYPE</code> in <code>luaconf.h</code>.)
+
+
+<p>
+Lua also defines the constants
+<a name="pdf-LUA_MININTEGER"><code>LUA_MININTEGER</code></a> and <a name="pdf-LUA_MAXINTEGER"><code>LUA_MAXINTEGER</code></a>,
+with the minimum and the maximum values that fit in this type.
+
+
+
+
+
+<hr><h3><a name="lua_isboolean"><code>lua_isboolean</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isboolean (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a boolean,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_iscfunction"><code>lua_iscfunction</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_iscfunction (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a C&nbsp;function,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isfunction"><code>lua_isfunction</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isfunction (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a function
+(either C or Lua), and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isinteger"><code>lua_isinteger</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isinteger (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is an integer
+(that is, the value is a number and is represented as an integer),
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_islightuserdata"><code>lua_islightuserdata</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_islightuserdata (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a light userdata,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isnil"><code>lua_isnil</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isnil (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is <b>nil</b>,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isnone"><code>lua_isnone</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isnone (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the given index is not valid,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isnoneornil"><code>lua_isnoneornil</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isnoneornil (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the given index is not valid
+or if the value at this index is <b>nil</b>,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isnumber"><code>lua_isnumber</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isnumber (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a number
+or a string convertible to a number,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isstring"><code>lua_isstring</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isstring (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a string
+or a number (which is always convertible to a string),
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_istable"><code>lua_istable</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_istable (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a table,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isthread"><code>lua_isthread</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isthread (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a thread,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isuserdata"><code>lua_isuserdata</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isuserdata (lua_State *L, int index);</pre>
+
+<p>
+Returns 1 if the value at the given index is a userdata
+(either full or light), and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_isyieldable"><code>lua_isyieldable</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_isyieldable (lua_State *L);</pre>
+
+<p>
+Returns 1 if the given coroutine can yield,
+and 0&nbsp;otherwise.
+
+
+
+
+
+<hr><h3><a name="lua_KContext"><code>lua_KContext</code></a></h3>
+<pre>typedef ... lua_KContext;</pre>
+
+<p>
+The type for continuation-function contexts.
+It must be a numeric type.
+This type is defined as <code>intptr_t</code>
+when <code>intptr_t</code> is available,
+so that it can store pointers too.
+Otherwise, it is defined as <code>ptrdiff_t</code>.
+
+
+
+
+
+<hr><h3><a name="lua_KFunction"><code>lua_KFunction</code></a></h3>
+<pre>typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx);</pre>
+
+<p>
+Type for continuation functions (see <a href="#4.7">&sect;4.7</a>).
+
+
+
+
+
+<hr><h3><a name="lua_len"><code>lua_len</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>void lua_len (lua_State *L, int index);</pre>
+
+<p>
+Returns the length of the value at the given index.
+It is equivalent to the '<code>#</code>' operator in Lua (see <a href="#3.4.7">&sect;3.4.7</a>) and
+may trigger a metamethod for the "length" event (see <a href="#2.4">&sect;2.4</a>).
+The result is pushed on the stack.
+
+
+
+
+
+<hr><h3><a name="lua_load"><code>lua_load</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int lua_load (lua_State *L,
+              lua_Reader reader,
+              void *data,
+              const char *chunkname,
+              const char *mode);</pre>
+
+<p>
+Loads a Lua chunk without running it.
+If there are no errors,
+<code>lua_load</code> pushes the compiled chunk as a Lua
+function on top of the stack.
+Otherwise, it pushes an error message.
+
+
+<p>
+The return values of <code>lua_load</code> are:
+
+<ul>
+
+<li><b><a href="#pdf-LUA_OK"><code>LUA_OK</code></a>: </b> no errors;</li>
+
+<li><b><a name="pdf-LUA_ERRSYNTAX"><code>LUA_ERRSYNTAX</code></a>: </b>
+syntax error during precompilation;</li>
+
+<li><b><a href="#pdf-LUA_ERRMEM"><code>LUA_ERRMEM</code></a>: </b>
+memory allocation (out-of-memory) error;</li>
+
+<li><b><a href="#pdf-LUA_ERRGCMM"><code>LUA_ERRGCMM</code></a>: </b>
+error while running a <code>__gc</code> metamethod.
+(This error has no relation with the chunk being loaded.
+It is generated by the garbage collector.)
+</li>
+
+</ul>
+
+<p>
+The <code>lua_load</code> function uses a user-supplied <code>reader</code> function
+to read the chunk (see <a href="#lua_Reader"><code>lua_Reader</code></a>).
+The <code>data</code> argument is an opaque value passed to the reader function.
+
+
+<p>
+The <code>chunkname</code> argument gives a name to the chunk,
+which is used for error messages and in debug information (see <a href="#4.9">&sect;4.9</a>).
+
+
+<p>
+<code>lua_load</code> automatically detects whether the chunk is text or binary
+and loads it accordingly (see program <code>luac</code>).
+The string <code>mode</code> works as in function <a href="#pdf-load"><code>load</code></a>,
+with the addition that
+a <code>NULL</code> value is equivalent to the string "<code>bt</code>".
+
+
+<p>
+<code>lua_load</code> uses the stack internally,
+so the reader function must always leave the stack
+unmodified when returning.
+
+
+<p>
+If the resulting function has upvalues,
+its first upvalue is set to the value of the global environment
+stored at index <code>LUA_RIDX_GLOBALS</code> in the registry (see <a href="#4.5">&sect;4.5</a>).
+When loading main chunks,
+this upvalue will be the <code>_ENV</code> variable (see <a href="#2.2">&sect;2.2</a>).
+Other upvalues are initialized with <b>nil</b>.
+
+
+
+
+
+<hr><h3><a name="lua_newstate"><code>lua_newstate</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_State *lua_newstate (lua_Alloc f, void *ud);</pre>
+
+<p>
+Creates a new thread running in a new, independent state.
+Returns <code>NULL</code> if it cannot create the thread or the state
+(due to lack of memory).
+The argument <code>f</code> is the allocator function;
+Lua does all memory allocation for this state through this function.
+The second argument, <code>ud</code>, is an opaque pointer that Lua
+passes to the allocator in every call.
+
+
+
+
+
+<hr><h3><a name="lua_newtable"><code>lua_newtable</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void lua_newtable (lua_State *L);</pre>
+
+<p>
+Creates a new empty table and pushes it onto the stack.
+It is equivalent to <code>lua_createtable(L, 0, 0)</code>.
+
+
+
+
+
+<hr><h3><a name="lua_newthread"><code>lua_newthread</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>lua_State *lua_newthread (lua_State *L);</pre>
+
+<p>
+Creates a new thread, pushes it on the stack,
+and returns a pointer to a <a href="#lua_State"><code>lua_State</code></a> that represents this new thread.
+The new thread returned by this function shares with the original thread
+its global environment,
+but has an independent execution stack.
+
+
+<p>
+There is no explicit function to close or to destroy a thread.
+Threads are subject to garbage collection,
+like any Lua object.
+
+
+
+
+
+<hr><h3><a name="lua_newuserdata"><code>lua_newuserdata</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void *lua_newuserdata (lua_State *L, size_t size);</pre>
+
+<p>
+This function allocates a new block of memory with the given size,
+pushes onto the stack a new full userdata with the block address,
+and returns this address.
+The host program can freely use this memory.
+
+
+
+
+
+<hr><h3><a name="lua_next"><code>lua_next</code></a></h3><p>
+<span class="apii">[-1, +(2|0), <em>e</em>]</span>
+<pre>int lua_next (lua_State *L, int index);</pre>
+
+<p>
+Pops a key from the stack,
+and pushes a key&ndash;value pair from the table at the given index
+(the "next" pair after the given key).
+If there are no more elements in the table,
+then <a href="#lua_next"><code>lua_next</code></a> returns 0 (and pushes nothing).
+
+
+<p>
+A typical traversal looks like this:
+
+<pre>
+     /* table is in the stack at index 't' */
+     lua_pushnil(L);  /* first key */
+     while (lua_next(L, t) != 0) {
+       /* uses 'key' (at index -2) and 'value' (at index -1) */
+       printf("%s - %s\n",
+              lua_typename(L, lua_type(L, -2)),
+              lua_typename(L, lua_type(L, -1)));
+       /* removes 'value'; keeps 'key' for next iteration */
+       lua_pop(L, 1);
+     }
+</pre>
+
+<p>
+While traversing a table,
+do not call <a href="#lua_tolstring"><code>lua_tolstring</code></a> directly on a key,
+unless you know that the key is actually a string.
+Recall that <a href="#lua_tolstring"><code>lua_tolstring</code></a> may change
+the value at the given index;
+this confuses the next call to <a href="#lua_next"><code>lua_next</code></a>.
+
+
+<p>
+See function <a href="#pdf-next"><code>next</code></a> for the caveats of modifying
+the table during its traversal.
+
+
+
+
+
+<hr><h3><a name="lua_Number"><code>lua_Number</code></a></h3>
+<pre>typedef ... lua_Number;</pre>
+
+<p>
+The type of floats in Lua.
+
+
+<p>
+By default this type is double,
+but that can be changed to a single float or a long double.
+(See <code>LUA_FLOAT_TYPE</code> in <code>luaconf.h</code>.)
+
+
+
+
+
+<hr><h3><a name="lua_numbertointeger"><code>lua_numbertointeger</code></a></h3>
+<pre>int lua_numbertointeger (lua_Number n, lua_Integer *p);</pre>
+
+<p>
+Converts a Lua float to a Lua integer.
+This macro assumes that <code>n</code> has an integral value.
+If that value is within the range of Lua integers,
+it is converted to an integer and assigned to <code>*p</code>.
+The macro results in a boolean indicating whether the
+conversion was successful.
+(Note that this range test can be tricky to do
+correctly without this macro,
+due to roundings.)
+
+
+<p>
+This macro may evaluate its arguments more than once.
+
+
+
+
+
+<hr><h3><a name="lua_pcall"><code>lua_pcall</code></a></h3><p>
+<span class="apii">[-(nargs + 1), +(nresults|1), &ndash;]</span>
+<pre>int lua_pcall (lua_State *L, int nargs, int nresults, int msgh);</pre>
+
+<p>
+Calls a function in protected mode.
+
+
+<p>
+Both <code>nargs</code> and <code>nresults</code> have the same meaning as
+in <a href="#lua_call"><code>lua_call</code></a>.
+If there are no errors during the call,
+<a href="#lua_pcall"><code>lua_pcall</code></a> behaves exactly like <a href="#lua_call"><code>lua_call</code></a>.
+However, if there is any error,
+<a href="#lua_pcall"><code>lua_pcall</code></a> catches it,
+pushes a single value on the stack (the error object),
+and returns an error code.
+Like <a href="#lua_call"><code>lua_call</code></a>,
+<a href="#lua_pcall"><code>lua_pcall</code></a> always removes the function
+and its arguments from the stack.
+
+
+<p>
+If <code>msgh</code> is 0,
+then the error object returned on the stack
+is exactly the original error object.
+Otherwise, <code>msgh</code> is the stack index of a
+<em>message handler</em>.
+(This index cannot be a pseudo-index.)
+In case of runtime errors,
+this function will be called with the error object
+and its return value will be the object
+returned on the stack by <a href="#lua_pcall"><code>lua_pcall</code></a>.
+
+
+<p>
+Typically, the message handler is used to add more debug
+information to the error object, such as a stack traceback.
+Such information cannot be gathered after the return of <a href="#lua_pcall"><code>lua_pcall</code></a>,
+since by then the stack has unwound.
+
+
+<p>
+The <a href="#lua_pcall"><code>lua_pcall</code></a> function returns one of the following constants
+(defined in <code>lua.h</code>):
+
+<ul>
+
+<li><b><a name="pdf-LUA_OK"><code>LUA_OK</code></a> (0): </b>
+success.</li>
+
+<li><b><a name="pdf-LUA_ERRRUN"><code>LUA_ERRRUN</code></a>: </b>
+a runtime error.
+</li>
+
+<li><b><a name="pdf-LUA_ERRMEM"><code>LUA_ERRMEM</code></a>: </b>
+memory allocation error.
+For such errors, Lua does not call the message handler.
+</li>
+
+<li><b><a name="pdf-LUA_ERRERR"><code>LUA_ERRERR</code></a>: </b>
+error while running the message handler.
+</li>
+
+<li><b><a name="pdf-LUA_ERRGCMM"><code>LUA_ERRGCMM</code></a>: </b>
+error while running a <code>__gc</code> metamethod.
+(This error typically has no relation with the function being called.)
+</li>
+
+</ul>
+
+
+
+
+<hr><h3><a name="lua_pcallk"><code>lua_pcallk</code></a></h3><p>
+<span class="apii">[-(nargs + 1), +(nresults|1), &ndash;]</span>
+<pre>int lua_pcallk (lua_State *L,
+                int nargs,
+                int nresults,
+                int msgh,
+                lua_KContext ctx,
+                lua_KFunction k);</pre>
+
+<p>
+This function behaves exactly like <a href="#lua_pcall"><code>lua_pcall</code></a>,
+but allows the called function to yield (see <a href="#4.7">&sect;4.7</a>).
+
+
+
+
+
+<hr><h3><a name="lua_pop"><code>lua_pop</code></a></h3><p>
+<span class="apii">[-n, +0, &ndash;]</span>
+<pre>void lua_pop (lua_State *L, int n);</pre>
+
+<p>
+Pops <code>n</code> elements from the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushboolean"><code>lua_pushboolean</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushboolean (lua_State *L, int b);</pre>
+
+<p>
+Pushes a boolean value with value <code>b</code> onto the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushcclosure"><code>lua_pushcclosure</code></a></h3><p>
+<span class="apii">[-n, +1, <em>m</em>]</span>
+<pre>void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);</pre>
+
+<p>
+Pushes a new C&nbsp;closure onto the stack.
+
+
+<p>
+When a C&nbsp;function is created,
+it is possible to associate some values with it,
+thus creating a C&nbsp;closure (see <a href="#4.4">&sect;4.4</a>);
+these values are then accessible to the function whenever it is called.
+To associate values with a C&nbsp;function,
+first these values must be pushed onto the stack
+(when there are multiple values, the first value is pushed first).
+Then <a href="#lua_pushcclosure"><code>lua_pushcclosure</code></a>
+is called to create and push the C&nbsp;function onto the stack,
+with the argument <code>n</code> telling how many values will be
+associated with the function.
+<a href="#lua_pushcclosure"><code>lua_pushcclosure</code></a> also pops these values from the stack.
+
+
+<p>
+The maximum value for <code>n</code> is 255.
+
+
+<p>
+When <code>n</code> is zero,
+this function creates a <em>light C function</em>,
+which is just a pointer to the C&nbsp;function.
+In that case, it never raises a memory error.
+
+
+
+
+
+<hr><h3><a name="lua_pushcfunction"><code>lua_pushcfunction</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushcfunction (lua_State *L, lua_CFunction f);</pre>
+
+<p>
+Pushes a C&nbsp;function onto the stack.
+This function receives a pointer to a C function
+and pushes onto the stack a Lua value of type <code>function</code> that,
+when called, invokes the corresponding C&nbsp;function.
+
+
+<p>
+Any function to be callable by Lua must
+follow the correct protocol to receive its parameters
+and return its results (see <a href="#lua_CFunction"><code>lua_CFunction</code></a>).
+
+
+
+
+
+<hr><h3><a name="lua_pushfstring"><code>lua_pushfstring</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>const char *lua_pushfstring (lua_State *L, const char *fmt, ...);</pre>
+
+<p>
+Pushes onto the stack a formatted string
+and returns a pointer to this string.
+It is similar to the ISO&nbsp;C function <code>sprintf</code>,
+but has some important differences:
+
+<ul>
+
+<li>
+You do not have to allocate space for the result:
+the result is a Lua string and Lua takes care of memory allocation
+(and deallocation, through garbage collection).
+</li>
+
+<li>
+The conversion specifiers are quite restricted.
+There are no flags, widths, or precisions.
+The conversion specifiers can only be
+'<code>%%</code>' (inserts the character '<code>%</code>'),
+'<code>%s</code>' (inserts a zero-terminated string, with no size restrictions),
+'<code>%f</code>' (inserts a <a href="#lua_Number"><code>lua_Number</code></a>),
+'<code>%I</code>' (inserts a <a href="#lua_Integer"><code>lua_Integer</code></a>),
+'<code>%p</code>' (inserts a pointer as a hexadecimal numeral),
+'<code>%d</code>' (inserts an <code>int</code>),
+'<code>%c</code>' (inserts an <code>int</code> as a one-byte character), and
+'<code>%U</code>' (inserts a <code>long int</code> as a UTF-8 byte sequence).
+</li>
+
+</ul>
+
+<p>
+Unlike other push functions,
+this function checks for the stack space it needs,
+including the slot for its result.
+
+
+
+
+
+<hr><h3><a name="lua_pushglobaltable"><code>lua_pushglobaltable</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushglobaltable (lua_State *L);</pre>
+
+<p>
+Pushes the global environment onto the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushinteger"><code>lua_pushinteger</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushinteger (lua_State *L, lua_Integer n);</pre>
+
+<p>
+Pushes an integer with value <code>n</code> onto the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushlightuserdata"><code>lua_pushlightuserdata</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushlightuserdata (lua_State *L, void *p);</pre>
+
+<p>
+Pushes a light userdata onto the stack.
+
+
+<p>
+Userdata represent C&nbsp;values in Lua.
+A <em>light userdata</em> represents a pointer, a <code>void*</code>.
+It is a value (like a number):
+you do not create it, it has no individual metatable,
+and it is not collected (as it was never created).
+A light userdata is equal to "any"
+light userdata with the same C&nbsp;address.
+
+
+
+
+
+<hr><h3><a name="lua_pushliteral"><code>lua_pushliteral</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>const char *lua_pushliteral (lua_State *L, const char *s);</pre>
+
+<p>
+This macro is equivalent to <a href="#lua_pushstring"><code>lua_pushstring</code></a>,
+but should be used only when <code>s</code> is a literal string.
+
+
+
+
+
+<hr><h3><a name="lua_pushlstring"><code>lua_pushlstring</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>const char *lua_pushlstring (lua_State *L, const char *s, size_t len);</pre>
+
+<p>
+Pushes the string pointed to by <code>s</code> with size <code>len</code>
+onto the stack.
+Lua makes (or reuses) an internal copy of the given string,
+so the memory at <code>s</code> can be freed or reused immediately after
+the function returns.
+The string can contain any binary data,
+including embedded zeros.
+
+
+<p>
+Returns a pointer to the internal copy of the string.
+
+
+
+
+
+<hr><h3><a name="lua_pushnil"><code>lua_pushnil</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushnil (lua_State *L);</pre>
+
+<p>
+Pushes a nil value onto the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushnumber"><code>lua_pushnumber</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushnumber (lua_State *L, lua_Number n);</pre>
+
+<p>
+Pushes a float with value <code>n</code> onto the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushstring"><code>lua_pushstring</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>const char *lua_pushstring (lua_State *L, const char *s);</pre>
+
+<p>
+Pushes the zero-terminated string pointed to by <code>s</code>
+onto the stack.
+Lua makes (or reuses) an internal copy of the given string,
+so the memory at <code>s</code> can be freed or reused immediately after
+the function returns.
+
+
+<p>
+Returns a pointer to the internal copy of the string.
+
+
+<p>
+If <code>s</code> is <code>NULL</code>, pushes <b>nil</b> and returns <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_pushthread"><code>lua_pushthread</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int lua_pushthread (lua_State *L);</pre>
+
+<p>
+Pushes the thread represented by <code>L</code> onto the stack.
+Returns 1 if this thread is the main thread of its state.
+
+
+
+
+
+<hr><h3><a name="lua_pushvalue"><code>lua_pushvalue</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>void lua_pushvalue (lua_State *L, int index);</pre>
+
+<p>
+Pushes a copy of the element at the given index
+onto the stack.
+
+
+
+
+
+<hr><h3><a name="lua_pushvfstring"><code>lua_pushvfstring</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>const char *lua_pushvfstring (lua_State *L,
+                              const char *fmt,
+                              va_list argp);</pre>
+
+<p>
+Equivalent to <a href="#lua_pushfstring"><code>lua_pushfstring</code></a>, except that it receives a <code>va_list</code>
+instead of a variable number of arguments.
+
+
+
+
+
+<hr><h3><a name="lua_rawequal"><code>lua_rawequal</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_rawequal (lua_State *L, int index1, int index2);</pre>
+
+<p>
+Returns 1 if the two values in indices <code>index1</code> and
+<code>index2</code> are primitively equal
+(that is, without calling the <code>__eq</code> metamethod).
+Otherwise returns&nbsp;0.
+Also returns&nbsp;0 if any of the indices are not valid.
+
+
+
+
+
+<hr><h3><a name="lua_rawget"><code>lua_rawget</code></a></h3><p>
+<span class="apii">[-1, +1, &ndash;]</span>
+<pre>int lua_rawget (lua_State *L, int index);</pre>
+
+<p>
+Similar to <a href="#lua_gettable"><code>lua_gettable</code></a>, but does a raw access
+(i.e., without metamethods).
+
+
+
+
+
+<hr><h3><a name="lua_rawgeti"><code>lua_rawgeti</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int lua_rawgeti (lua_State *L, int index, lua_Integer n);</pre>
+
+<p>
+Pushes onto the stack the value <code>t[n]</code>,
+where <code>t</code> is the table at the given index.
+The access is raw,
+that is, it does not invoke the <code>__index</code> metamethod.
+
+
+<p>
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="lua_rawgetp"><code>lua_rawgetp</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int lua_rawgetp (lua_State *L, int index, const void *p);</pre>
+
+<p>
+Pushes onto the stack the value <code>t[k]</code>,
+where <code>t</code> is the table at the given index and
+<code>k</code> is the pointer <code>p</code> represented as a light userdata.
+The access is raw;
+that is, it does not invoke the <code>__index</code> metamethod.
+
+
+<p>
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="lua_rawlen"><code>lua_rawlen</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>size_t lua_rawlen (lua_State *L, int index);</pre>
+
+<p>
+Returns the raw "length" of the value at the given index:
+for strings, this is the string length;
+for tables, this is the result of the length operator ('<code>#</code>')
+with no metamethods;
+for userdata, this is the size of the block of memory allocated
+for the userdata;
+for other values, it is&nbsp;0.
+
+
+
+
+
+<hr><h3><a name="lua_rawset"><code>lua_rawset</code></a></h3><p>
+<span class="apii">[-2, +0, <em>m</em>]</span>
+<pre>void lua_rawset (lua_State *L, int index);</pre>
+
+<p>
+Similar to <a href="#lua_settable"><code>lua_settable</code></a>, but does a raw assignment
+(i.e., without metamethods).
+
+
+
+
+
+<hr><h3><a name="lua_rawseti"><code>lua_rawseti</code></a></h3><p>
+<span class="apii">[-1, +0, <em>m</em>]</span>
+<pre>void lua_rawseti (lua_State *L, int index, lua_Integer i);</pre>
+
+<p>
+Does the equivalent of <code>t[i] = v</code>,
+where <code>t</code> is the table at the given index
+and <code>v</code> is the value at the top of the stack.
+
+
+<p>
+This function pops the value from the stack.
+The assignment is raw,
+that is, it does not invoke the <code>__newindex</code> metamethod.
+
+
+
+
+
+<hr><h3><a name="lua_rawsetp"><code>lua_rawsetp</code></a></h3><p>
+<span class="apii">[-1, +0, <em>m</em>]</span>
+<pre>void lua_rawsetp (lua_State *L, int index, const void *p);</pre>
+
+<p>
+Does the equivalent of <code>t[p] = v</code>,
+where <code>t</code> is the table at the given index,
+<code>p</code> is encoded as a light userdata,
+and <code>v</code> is the value at the top of the stack.
+
+
+<p>
+This function pops the value from the stack.
+The assignment is raw,
+that is, it does not invoke <code>__newindex</code> metamethod.
+
+
+
+
+
+<hr><h3><a name="lua_Reader"><code>lua_Reader</code></a></h3>
+<pre>typedef const char * (*lua_Reader) (lua_State *L,
+                                    void *data,
+                                    size_t *size);</pre>
+
+<p>
+The reader function used by <a href="#lua_load"><code>lua_load</code></a>.
+Every time it needs another piece of the chunk,
+<a href="#lua_load"><code>lua_load</code></a> calls the reader,
+passing along its <code>data</code> parameter.
+The reader must return a pointer to a block of memory
+with a new piece of the chunk
+and set <code>size</code> to the block size.
+The block must exist until the reader function is called again.
+To signal the end of the chunk,
+the reader must return <code>NULL</code> or set <code>size</code> to zero.
+The reader function may return pieces of any size greater than zero.
+
+
+
+
+
+<hr><h3><a name="lua_register"><code>lua_register</code></a></h3><p>
+<span class="apii">[-0, +0, <em>e</em>]</span>
+<pre>void lua_register (lua_State *L, const char *name, lua_CFunction f);</pre>
+
+<p>
+Sets the C function <code>f</code> as the new value of global <code>name</code>.
+It is defined as a macro:
+
+<pre>
+     #define lua_register(L,n,f) \
+            (lua_pushcfunction(L, f), lua_setglobal(L, n))
+</pre>
+
+
+
+
+<hr><h3><a name="lua_remove"><code>lua_remove</code></a></h3><p>
+<span class="apii">[-1, +0, &ndash;]</span>
+<pre>void lua_remove (lua_State *L, int index);</pre>
+
+<p>
+Removes the element at the given valid index,
+shifting down the elements above this index to fill the gap.
+This function cannot be called with a pseudo-index,
+because a pseudo-index is not an actual stack position.
+
+
+
+
+
+<hr><h3><a name="lua_replace"><code>lua_replace</code></a></h3><p>
+<span class="apii">[-1, +0, &ndash;]</span>
+<pre>void lua_replace (lua_State *L, int index);</pre>
+
+<p>
+Moves the top element into the given valid index
+without shifting any element
+(therefore replacing the value at that given index),
+and then pops the top element.
+
+
+
+
+
+<hr><h3><a name="lua_resume"><code>lua_resume</code></a></h3><p>
+<span class="apii">[-?, +?, &ndash;]</span>
+<pre>int lua_resume (lua_State *L, lua_State *from, int nargs);</pre>
+
+<p>
+Starts and resumes a coroutine in the given thread <code>L</code>.
+
+
+<p>
+To start a coroutine,
+you push onto the thread stack the main function plus any arguments;
+then you call <a href="#lua_resume"><code>lua_resume</code></a>,
+with <code>nargs</code> being the number of arguments.
+This call returns when the coroutine suspends or finishes its execution.
+When it returns, the stack contains all values passed to <a href="#lua_yield"><code>lua_yield</code></a>,
+or all values returned by the body function.
+<a href="#lua_resume"><code>lua_resume</code></a> returns
+<a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> if the coroutine yields,
+<a href="#pdf-LUA_OK"><code>LUA_OK</code></a> if the coroutine finishes its execution
+without errors,
+or an error code in case of errors (see <a href="#lua_pcall"><code>lua_pcall</code></a>).
+
+
+<p>
+In case of errors,
+the stack is not unwound,
+so you can use the debug API over it.
+The error object is on the top of the stack.
+
+
+<p>
+To resume a coroutine,
+you remove any results from the last <a href="#lua_yield"><code>lua_yield</code></a>,
+put on its stack only the values to
+be passed as results from <code>yield</code>,
+and then call <a href="#lua_resume"><code>lua_resume</code></a>.
+
+
+<p>
+The parameter <code>from</code> represents the coroutine that is resuming <code>L</code>.
+If there is no such coroutine,
+this parameter can be <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_rotate"><code>lua_rotate</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void lua_rotate (lua_State *L, int idx, int n);</pre>
+
+<p>
+Rotates the stack elements between the valid index <code>idx</code>
+and the top of the stack.
+The elements are rotated <code>n</code> positions in the direction of the top,
+for a positive <code>n</code>,
+or <code>-n</code> positions in the direction of the bottom,
+for a negative <code>n</code>.
+The absolute value of <code>n</code> must not be greater than the size
+of the slice being rotated.
+This function cannot be called with a pseudo-index,
+because a pseudo-index is not an actual stack position.
+
+
+
+
+
+<hr><h3><a name="lua_setallocf"><code>lua_setallocf</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void lua_setallocf (lua_State *L, lua_Alloc f, void *ud);</pre>
+
+<p>
+Changes the allocator function of a given state to <code>f</code>
+with user data <code>ud</code>.
+
+
+
+
+
+<hr><h3><a name="lua_setfield"><code>lua_setfield</code></a></h3><p>
+<span class="apii">[-1, +0, <em>e</em>]</span>
+<pre>void lua_setfield (lua_State *L, int index, const char *k);</pre>
+
+<p>
+Does the equivalent to <code>t[k] = v</code>,
+where <code>t</code> is the value at the given index
+and <code>v</code> is the value at the top of the stack.
+
+
+<p>
+This function pops the value from the stack.
+As in Lua, this function may trigger a metamethod
+for the "newindex" event (see <a href="#2.4">&sect;2.4</a>).
+
+
+
+
+
+<hr><h3><a name="lua_setglobal"><code>lua_setglobal</code></a></h3><p>
+<span class="apii">[-1, +0, <em>e</em>]</span>
+<pre>void lua_setglobal (lua_State *L, const char *name);</pre>
+
+<p>
+Pops a value from the stack and
+sets it as the new value of global <code>name</code>.
+
+
+
+
+
+<hr><h3><a name="lua_seti"><code>lua_seti</code></a></h3><p>
+<span class="apii">[-1, +0, <em>e</em>]</span>
+<pre>void lua_seti (lua_State *L, int index, lua_Integer n);</pre>
+
+<p>
+Does the equivalent to <code>t[n] = v</code>,
+where <code>t</code> is the value at the given index
+and <code>v</code> is the value at the top of the stack.
+
+
+<p>
+This function pops the value from the stack.
+As in Lua, this function may trigger a metamethod
+for the "newindex" event (see <a href="#2.4">&sect;2.4</a>).
+
+
+
+
+
+<hr><h3><a name="lua_setmetatable"><code>lua_setmetatable</code></a></h3><p>
+<span class="apii">[-1, +0, &ndash;]</span>
+<pre>void lua_setmetatable (lua_State *L, int index);</pre>
+
+<p>
+Pops a table from the stack and
+sets it as the new metatable for the value at the given index.
+
+
+
+
+
+<hr><h3><a name="lua_settable"><code>lua_settable</code></a></h3><p>
+<span class="apii">[-2, +0, <em>e</em>]</span>
+<pre>void lua_settable (lua_State *L, int index);</pre>
+
+<p>
+Does the equivalent to <code>t[k] = v</code>,
+where <code>t</code> is the value at the given index,
+<code>v</code> is the value at the top of the stack,
+and <code>k</code> is the value just below the top.
+
+
+<p>
+This function pops both the key and the value from the stack.
+As in Lua, this function may trigger a metamethod
+for the "newindex" event (see <a href="#2.4">&sect;2.4</a>).
+
+
+
+
+
+<hr><h3><a name="lua_settop"><code>lua_settop</code></a></h3><p>
+<span class="apii">[-?, +?, &ndash;]</span>
+<pre>void lua_settop (lua_State *L, int index);</pre>
+
+<p>
+Accepts any index, or&nbsp;0,
+and sets the stack top to this index.
+If the new top is larger than the old one,
+then the new elements are filled with <b>nil</b>.
+If <code>index</code> is&nbsp;0, then all stack elements are removed.
+
+
+
+
+
+<hr><h3><a name="lua_setuservalue"><code>lua_setuservalue</code></a></h3><p>
+<span class="apii">[-1, +0, &ndash;]</span>
+<pre>void lua_setuservalue (lua_State *L, int index);</pre>
+
+<p>
+Pops a value from the stack and sets it as
+the new value associated to the userdata at the given index.
+
+
+
+
+
+<hr><h3><a name="lua_State"><code>lua_State</code></a></h3>
+<pre>typedef struct lua_State lua_State;</pre>
+
+<p>
+An opaque structure that points to a thread and indirectly
+(through the thread) to the whole state of a Lua interpreter.
+The Lua library is fully reentrant:
+it has no global variables.
+All information about a state is accessible through this structure.
+
+
+<p>
+A pointer to this structure must be passed as the first argument to
+every function in the library, except to <a href="#lua_newstate"><code>lua_newstate</code></a>,
+which creates a Lua state from scratch.
+
+
+
+
+
+<hr><h3><a name="lua_status"><code>lua_status</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_status (lua_State *L);</pre>
+
+<p>
+Returns the status of the thread <code>L</code>.
+
+
+<p>
+The status can be 0 (<a href="#pdf-LUA_OK"><code>LUA_OK</code></a>) for a normal thread,
+an error code if the thread finished the execution
+of a <a href="#lua_resume"><code>lua_resume</code></a> with an error,
+or <a name="pdf-LUA_YIELD"><code>LUA_YIELD</code></a> if the thread is suspended.
+
+
+<p>
+You can only call functions in threads with status <a href="#pdf-LUA_OK"><code>LUA_OK</code></a>.
+You can resume threads with status <a href="#pdf-LUA_OK"><code>LUA_OK</code></a>
+(to start a new coroutine) or <a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a>
+(to resume a coroutine).
+
+
+
+
+
+<hr><h3><a name="lua_stringtonumber"><code>lua_stringtonumber</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>size_t lua_stringtonumber (lua_State *L, const char *s);</pre>
+
+<p>
+Converts the zero-terminated string <code>s</code> to a number,
+pushes that number into the stack,
+and returns the total size of the string,
+that is, its length plus one.
+The conversion can result in an integer or a float,
+according to the lexical conventions of Lua (see <a href="#3.1">&sect;3.1</a>).
+The string may have leading and trailing spaces and a sign.
+If the string is not a valid numeral,
+returns 0 and pushes nothing.
+(Note that the result can be used as a boolean,
+true if the conversion succeeds.)
+
+
+
+
+
+<hr><h3><a name="lua_toboolean"><code>lua_toboolean</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_toboolean (lua_State *L, int index);</pre>
+
+<p>
+Converts the Lua value at the given index to a C&nbsp;boolean
+value (0&nbsp;or&nbsp;1).
+Like all tests in Lua,
+<a href="#lua_toboolean"><code>lua_toboolean</code></a> returns true for any Lua value
+different from <b>false</b> and <b>nil</b>;
+otherwise it returns false.
+(If you want to accept only actual boolean values,
+use <a href="#lua_isboolean"><code>lua_isboolean</code></a> to test the value's type.)
+
+
+
+
+
+<hr><h3><a name="lua_tocfunction"><code>lua_tocfunction</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_CFunction lua_tocfunction (lua_State *L, int index);</pre>
+
+<p>
+Converts a value at the given index to a C&nbsp;function.
+That value must be a C&nbsp;function;
+otherwise, returns <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_tointeger"><code>lua_tointeger</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_Integer lua_tointeger (lua_State *L, int index);</pre>
+
+<p>
+Equivalent to <a href="#lua_tointegerx"><code>lua_tointegerx</code></a> with <code>isnum</code> equal to <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_tointegerx"><code>lua_tointegerx</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_Integer lua_tointegerx (lua_State *L, int index, int *isnum);</pre>
+
+<p>
+Converts the Lua value at the given index
+to the signed integral type <a href="#lua_Integer"><code>lua_Integer</code></a>.
+The Lua value must be an integer,
+or a number or string convertible to an integer (see <a href="#3.4.3">&sect;3.4.3</a>);
+otherwise, <code>lua_tointegerx</code> returns&nbsp;0.
+
+
+<p>
+If <code>isnum</code> is not <code>NULL</code>,
+its referent is assigned a boolean value that
+indicates whether the operation succeeded.
+
+
+
+
+
+<hr><h3><a name="lua_tolstring"><code>lua_tolstring</code></a></h3><p>
+<span class="apii">[-0, +0, <em>m</em>]</span>
+<pre>const char *lua_tolstring (lua_State *L, int index, size_t *len);</pre>
+
+<p>
+Converts the Lua value at the given index to a C&nbsp;string.
+If <code>len</code> is not <code>NULL</code>,
+it sets <code>*len</code> with the string length.
+The Lua value must be a string or a number;
+otherwise, the function returns <code>NULL</code>.
+If the value is a number,
+then <code>lua_tolstring</code> also
+<em>changes the actual value in the stack to a string</em>.
+(This change confuses <a href="#lua_next"><code>lua_next</code></a>
+when <code>lua_tolstring</code> is applied to keys during a table traversal.)
+
+
+<p>
+<code>lua_tolstring</code> returns a pointer
+to a string inside the Lua state.
+This string always has a zero ('<code>\0</code>')
+after its last character (as in&nbsp;C),
+but can contain other zeros in its body.
+
+
+<p>
+Because Lua has garbage collection,
+there is no guarantee that the pointer returned by <code>lua_tolstring</code>
+will be valid after the corresponding Lua value is removed from the stack.
+
+
+
+
+
+<hr><h3><a name="lua_tonumber"><code>lua_tonumber</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_Number lua_tonumber (lua_State *L, int index);</pre>
+
+<p>
+Equivalent to <a href="#lua_tonumberx"><code>lua_tonumberx</code></a> with <code>isnum</code> equal to <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_tonumberx"><code>lua_tonumberx</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_Number lua_tonumberx (lua_State *L, int index, int *isnum);</pre>
+
+<p>
+Converts the Lua value at the given index
+to the C&nbsp;type <a href="#lua_Number"><code>lua_Number</code></a> (see <a href="#lua_Number"><code>lua_Number</code></a>).
+The Lua value must be a number or a string convertible to a number
+(see <a href="#3.4.3">&sect;3.4.3</a>);
+otherwise, <a href="#lua_tonumberx"><code>lua_tonumberx</code></a> returns&nbsp;0.
+
+
+<p>
+If <code>isnum</code> is not <code>NULL</code>,
+its referent is assigned a boolean value that
+indicates whether the operation succeeded.
+
+
+
+
+
+<hr><h3><a name="lua_topointer"><code>lua_topointer</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>const void *lua_topointer (lua_State *L, int index);</pre>
+
+<p>
+Converts the value at the given index to a generic
+C&nbsp;pointer (<code>void*</code>).
+The value can be a userdata, a table, a thread, or a function;
+otherwise, <code>lua_topointer</code> returns <code>NULL</code>.
+Different objects will give different pointers.
+There is no way to convert the pointer back to its original value.
+
+
+<p>
+Typically this function is used only for hashing and debug information.
+
+
+
+
+
+<hr><h3><a name="lua_tostring"><code>lua_tostring</code></a></h3><p>
+<span class="apii">[-0, +0, <em>m</em>]</span>
+<pre>const char *lua_tostring (lua_State *L, int index);</pre>
+
+<p>
+Equivalent to <a href="#lua_tolstring"><code>lua_tolstring</code></a> with <code>len</code> equal to <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_tothread"><code>lua_tothread</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_State *lua_tothread (lua_State *L, int index);</pre>
+
+<p>
+Converts the value at the given index to a Lua thread
+(represented as <code>lua_State*</code>).
+This value must be a thread;
+otherwise, the function returns <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_touserdata"><code>lua_touserdata</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void *lua_touserdata (lua_State *L, int index);</pre>
+
+<p>
+If the value at the given index is a full userdata,
+returns its block address.
+If the value is a light userdata,
+returns its pointer.
+Otherwise, returns <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="lua_type"><code>lua_type</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_type (lua_State *L, int index);</pre>
+
+<p>
+Returns the type of the value in the given valid index,
+or <code>LUA_TNONE</code> for a non-valid (but acceptable) index.
+The types returned by <a href="#lua_type"><code>lua_type</code></a> are coded by the following constants
+defined in <code>lua.h</code>:
+<a name="pdf-LUA_TNIL"><code>LUA_TNIL</code></a> (0),
+<a name="pdf-LUA_TNUMBER"><code>LUA_TNUMBER</code></a>,
+<a name="pdf-LUA_TBOOLEAN"><code>LUA_TBOOLEAN</code></a>,
+<a name="pdf-LUA_TSTRING"><code>LUA_TSTRING</code></a>,
+<a name="pdf-LUA_TTABLE"><code>LUA_TTABLE</code></a>,
+<a name="pdf-LUA_TFUNCTION"><code>LUA_TFUNCTION</code></a>,
+<a name="pdf-LUA_TUSERDATA"><code>LUA_TUSERDATA</code></a>,
+<a name="pdf-LUA_TTHREAD"><code>LUA_TTHREAD</code></a>,
+and
+<a name="pdf-LUA_TLIGHTUSERDATA"><code>LUA_TLIGHTUSERDATA</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_typename"><code>lua_typename</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>const char *lua_typename (lua_State *L, int tp);</pre>
+
+<p>
+Returns the name of the type encoded by the value <code>tp</code>,
+which must be one the values returned by <a href="#lua_type"><code>lua_type</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_Unsigned"><code>lua_Unsigned</code></a></h3>
+<pre>typedef ... lua_Unsigned;</pre>
+
+<p>
+The unsigned version of <a href="#lua_Integer"><code>lua_Integer</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_upvalueindex"><code>lua_upvalueindex</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_upvalueindex (int i);</pre>
+
+<p>
+Returns the pseudo-index that represents the <code>i</code>-th upvalue of
+the running function (see <a href="#4.4">&sect;4.4</a>).
+
+
+
+
+
+<hr><h3><a name="lua_version"><code>lua_version</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>const lua_Number *lua_version (lua_State *L);</pre>
+
+<p>
+Returns the address of the version number
+(a C static variable)
+stored in the Lua core.
+When called with a valid <a href="#lua_State"><code>lua_State</code></a>,
+returns the address of the version used to create that state.
+When called with <code>NULL</code>,
+returns the address of the version running the call.
+
+
+
+
+
+<hr><h3><a name="lua_Writer"><code>lua_Writer</code></a></h3>
+<pre>typedef int (*lua_Writer) (lua_State *L,
+                           const void* p,
+                           size_t sz,
+                           void* ud);</pre>
+
+<p>
+The type of the writer function used by <a href="#lua_dump"><code>lua_dump</code></a>.
+Every time it produces another piece of chunk,
+<a href="#lua_dump"><code>lua_dump</code></a> calls the writer,
+passing along the buffer to be written (<code>p</code>),
+its size (<code>sz</code>),
+and the <code>data</code> parameter supplied to <a href="#lua_dump"><code>lua_dump</code></a>.
+
+
+<p>
+The writer returns an error code:
+0&nbsp;means no errors;
+any other value means an error and stops <a href="#lua_dump"><code>lua_dump</code></a> from
+calling the writer again.
+
+
+
+
+
+<hr><h3><a name="lua_xmove"><code>lua_xmove</code></a></h3><p>
+<span class="apii">[-?, +?, &ndash;]</span>
+<pre>void lua_xmove (lua_State *from, lua_State *to, int n);</pre>
+
+<p>
+Exchange values between different threads of the same state.
+
+
+<p>
+This function pops <code>n</code> values from the stack <code>from</code>,
+and pushes them onto the stack <code>to</code>.
+
+
+
+
+
+<hr><h3><a name="lua_yield"><code>lua_yield</code></a></h3><p>
+<span class="apii">[-?, +?, <em>e</em>]</span>
+<pre>int lua_yield (lua_State *L, int nresults);</pre>
+
+<p>
+This function is equivalent to <a href="#lua_yieldk"><code>lua_yieldk</code></a>,
+but it has no continuation (see <a href="#4.7">&sect;4.7</a>).
+Therefore, when the thread resumes,
+it continues the function that called
+the function calling <code>lua_yield</code>.
+
+
+
+
+
+<hr><h3><a name="lua_yieldk"><code>lua_yieldk</code></a></h3><p>
+<span class="apii">[-?, +?, <em>e</em>]</span>
+<pre>int lua_yieldk (lua_State *L,
+                int nresults,
+                lua_KContext ctx,
+                lua_KFunction k);</pre>
+
+<p>
+Yields a coroutine (thread).
+
+
+<p>
+When a C&nbsp;function calls <a href="#lua_yieldk"><code>lua_yieldk</code></a>,
+the running coroutine suspends its execution,
+and the call to <a href="#lua_resume"><code>lua_resume</code></a> that started this coroutine returns.
+The parameter <code>nresults</code> is the number of values from the stack
+that will be passed as results to <a href="#lua_resume"><code>lua_resume</code></a>.
+
+
+<p>
+When the coroutine is resumed again,
+Lua calls the given continuation function <code>k</code> to continue
+the execution of the C function that yielded (see <a href="#4.7">&sect;4.7</a>).
+This continuation function receives the same stack
+from the previous function,
+with the <code>n</code> results removed and
+replaced by the arguments passed to <a href="#lua_resume"><code>lua_resume</code></a>.
+Moreover,
+the continuation function receives the value <code>ctx</code>
+that was passed to <a href="#lua_yieldk"><code>lua_yieldk</code></a>.
+
+
+<p>
+Usually, this function does not return;
+when the coroutine eventually resumes,
+it continues executing the continuation function.
+However, there is one special case,
+which is when this function is called
+from inside a line or a count hook (see <a href="#4.9">&sect;4.9</a>).
+In that case, <code>lua_yieldk</code> should be called with no continuation
+(probably in the form of <a href="#lua_yield"><code>lua_yield</code></a>) and no results,
+and the hook should return immediately after the call.
+Lua will yield and,
+when the coroutine resumes again,
+it will continue the normal execution
+of the (Lua) function that triggered the hook.
+
+
+<p>
+This function can raise an error if it is called from a thread
+with a pending C call with no continuation function,
+or it is called from a thread that is not running inside a resume
+(e.g., the main thread).
+
+
+
+
+
+
+
+<h2>4.9 &ndash; <a name="4.9">The Debug Interface</a></h2>
+
+<p>
+Lua has no built-in debugging facilities.
+Instead, it offers a special interface
+by means of functions and <em>hooks</em>.
+This interface allows the construction of different
+kinds of debuggers, profilers, and other tools
+that need "inside information" from the interpreter.
+
+
+
+<hr><h3><a name="lua_Debug"><code>lua_Debug</code></a></h3>
+<pre>typedef struct lua_Debug {
+  int event;
+  const char *name;           /* (n) */
+  const char *namewhat;       /* (n) */
+  const char *what;           /* (S) */
+  const char *source;         /* (S) */
+  int currentline;            /* (l) */
+  int linedefined;            /* (S) */
+  int lastlinedefined;        /* (S) */
+  unsigned char nups;         /* (u) number of upvalues */
+  unsigned char nparams;      /* (u) number of parameters */
+  char isvararg;              /* (u) */
+  char istailcall;            /* (t) */
+  char short_src[LUA_IDSIZE]; /* (S) */
+  /* private part */
+  <em>other fields</em>
+} lua_Debug;</pre>
+
+<p>
+A structure used to carry different pieces of
+information about a function or an activation record.
+<a href="#lua_getstack"><code>lua_getstack</code></a> fills only the private part
+of this structure, for later use.
+To fill the other fields of <a href="#lua_Debug"><code>lua_Debug</code></a> with useful information,
+call <a href="#lua_getinfo"><code>lua_getinfo</code></a>.
+
+
+<p>
+The fields of <a href="#lua_Debug"><code>lua_Debug</code></a> have the following meaning:
+
+<ul>
+
+<li><b><code>source</code>: </b>
+the name of the chunk that created the function.
+If <code>source</code> starts with a '<code>@</code>',
+it means that the function was defined in a file where
+the file name follows the '<code>@</code>'.
+If <code>source</code> starts with a '<code>=</code>',
+the remainder of its contents describe the source in a user-dependent manner.
+Otherwise,
+the function was defined in a string where
+<code>source</code> is that string.
+</li>
+
+<li><b><code>short_src</code>: </b>
+a "printable" version of <code>source</code>, to be used in error messages.
+</li>
+
+<li><b><code>linedefined</code>: </b>
+the line number where the definition of the function starts.
+</li>
+
+<li><b><code>lastlinedefined</code>: </b>
+the line number where the definition of the function ends.
+</li>
+
+<li><b><code>what</code>: </b>
+the string <code>"Lua"</code> if the function is a Lua function,
+<code>"C"</code> if it is a C&nbsp;function,
+<code>"main"</code> if it is the main part of a chunk.
+</li>
+
+<li><b><code>currentline</code>: </b>
+the current line where the given function is executing.
+When no line information is available,
+<code>currentline</code> is set to -1.
+</li>
+
+<li><b><code>name</code>: </b>
+a reasonable name for the given function.
+Because functions in Lua are first-class values,
+they do not have a fixed name:
+some functions can be the value of multiple global variables,
+while others can be stored only in a table field.
+The <code>lua_getinfo</code> function checks how the function was
+called to find a suitable name.
+If it cannot find a name,
+then <code>name</code> is set to <code>NULL</code>.
+</li>
+
+<li><b><code>namewhat</code>: </b>
+explains the <code>name</code> field.
+The value of <code>namewhat</code> can be
+<code>"global"</code>, <code>"local"</code>, <code>"method"</code>,
+<code>"field"</code>, <code>"upvalue"</code>, or <code>""</code> (the empty string),
+according to how the function was called.
+(Lua uses the empty string when no other option seems to apply.)
+</li>
+
+<li><b><code>istailcall</code>: </b>
+true if this function invocation was called by a tail call.
+In this case, the caller of this level is not in the stack.
+</li>
+
+<li><b><code>nups</code>: </b>
+the number of upvalues of the function.
+</li>
+
+<li><b><code>nparams</code>: </b>
+the number of fixed parameters of the function
+(always 0&nbsp;for C&nbsp;functions).
+</li>
+
+<li><b><code>isvararg</code>: </b>
+true if the function is a vararg function
+(always true for C&nbsp;functions).
+</li>
+
+</ul>
+
+
+
+
+<hr><h3><a name="lua_gethook"><code>lua_gethook</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_Hook lua_gethook (lua_State *L);</pre>
+
+<p>
+Returns the current hook function.
+
+
+
+
+
+<hr><h3><a name="lua_gethookcount"><code>lua_gethookcount</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_gethookcount (lua_State *L);</pre>
+
+<p>
+Returns the current hook count.
+
+
+
+
+
+<hr><h3><a name="lua_gethookmask"><code>lua_gethookmask</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_gethookmask (lua_State *L);</pre>
+
+<p>
+Returns the current hook mask.
+
+
+
+
+
+<hr><h3><a name="lua_getinfo"><code>lua_getinfo</code></a></h3><p>
+<span class="apii">[-(0|1), +(0|1|2), <em>e</em>]</span>
+<pre>int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);</pre>
+
+<p>
+Gets information about a specific function or function invocation.
+
+
+<p>
+To get information about a function invocation,
+the parameter <code>ar</code> must be a valid activation record that was
+filled by a previous call to <a href="#lua_getstack"><code>lua_getstack</code></a> or
+given as argument to a hook (see <a href="#lua_Hook"><code>lua_Hook</code></a>).
+
+
+<p>
+To get information about a function you push it onto the stack
+and start the <code>what</code> string with the character '<code>&gt;</code>'.
+(In that case,
+<code>lua_getinfo</code> pops the function from the top of the stack.)
+For instance, to know in which line a function <code>f</code> was defined,
+you can write the following code:
+
+<pre>
+     lua_Debug ar;
+     lua_getglobal(L, "f");  /* get global 'f' */
+     lua_getinfo(L, "&gt;S", &amp;ar);
+     printf("%d\n", ar.linedefined);
+</pre>
+
+<p>
+Each character in the string <code>what</code>
+selects some fields of the structure <code>ar</code> to be filled or
+a value to be pushed on the stack:
+
+<ul>
+
+<li><b>'<code>n</code>': </b> fills in the field <code>name</code> and <code>namewhat</code>;
+</li>
+
+<li><b>'<code>S</code>': </b>
+fills in the fields <code>source</code>, <code>short_src</code>,
+<code>linedefined</code>, <code>lastlinedefined</code>, and <code>what</code>;
+</li>
+
+<li><b>'<code>l</code>': </b> fills in the field <code>currentline</code>;
+</li>
+
+<li><b>'<code>t</code>': </b> fills in the field <code>istailcall</code>;
+</li>
+
+<li><b>'<code>u</code>': </b> fills in the fields
+<code>nups</code>, <code>nparams</code>, and <code>isvararg</code>;
+</li>
+
+<li><b>'<code>f</code>': </b>
+pushes onto the stack the function that is
+running at the given level;
+</li>
+
+<li><b>'<code>L</code>': </b>
+pushes onto the stack a table whose indices are the
+numbers of the lines that are valid on the function.
+(A <em>valid line</em> is a line with some associated code,
+that is, a line where you can put a break point.
+Non-valid lines include empty lines and comments.)
+
+
+<p>
+If this option is given together with option '<code>f</code>',
+its table is pushed after the function.
+</li>
+
+</ul>
+
+<p>
+This function returns 0 on error
+(for instance, an invalid option in <code>what</code>).
+
+
+
+
+
+<hr><h3><a name="lua_getlocal"><code>lua_getlocal</code></a></h3><p>
+<span class="apii">[-0, +(0|1), &ndash;]</span>
+<pre>const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);</pre>
+
+<p>
+Gets information about a local variable of
+a given activation record or a given function.
+
+
+<p>
+In the first case,
+the parameter <code>ar</code> must be a valid activation record that was
+filled by a previous call to <a href="#lua_getstack"><code>lua_getstack</code></a> or
+given as argument to a hook (see <a href="#lua_Hook"><code>lua_Hook</code></a>).
+The index <code>n</code> selects which local variable to inspect;
+see <a href="#pdf-debug.getlocal"><code>debug.getlocal</code></a> for details about variable indices
+and names.
+
+
+<p>
+<a href="#lua_getlocal"><code>lua_getlocal</code></a> pushes the variable's value onto the stack
+and returns its name.
+
+
+<p>
+In the second case, <code>ar</code> must be <code>NULL</code> and the function
+to be inspected must be at the top of the stack.
+In this case, only parameters of Lua functions are visible
+(as there is no information about what variables are active)
+and no values are pushed onto the stack.
+
+
+<p>
+Returns <code>NULL</code> (and pushes nothing)
+when the index is greater than
+the number of active local variables.
+
+
+
+
+
+<hr><h3><a name="lua_getstack"><code>lua_getstack</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>int lua_getstack (lua_State *L, int level, lua_Debug *ar);</pre>
+
+<p>
+Gets information about the interpreter runtime stack.
+
+
+<p>
+This function fills parts of a <a href="#lua_Debug"><code>lua_Debug</code></a> structure with
+an identification of the <em>activation record</em>
+of the function executing at a given level.
+Level&nbsp;0 is the current running function,
+whereas level <em>n+1</em> is the function that has called level <em>n</em>
+(except for tail calls, which do not count on the stack).
+When there are no errors, <a href="#lua_getstack"><code>lua_getstack</code></a> returns 1;
+when called with a level greater than the stack depth,
+it returns 0.
+
+
+
+
+
+<hr><h3><a name="lua_getupvalue"><code>lua_getupvalue</code></a></h3><p>
+<span class="apii">[-0, +(0|1), &ndash;]</span>
+<pre>const char *lua_getupvalue (lua_State *L, int funcindex, int n);</pre>
+
+<p>
+Gets information about the <code>n</code>-th upvalue
+of the closure at index <code>funcindex</code>.
+It pushes the upvalue's value onto the stack
+and returns its name.
+Returns <code>NULL</code> (and pushes nothing)
+when the index <code>n</code> is greater than the number of upvalues.
+
+
+<p>
+For C&nbsp;functions, this function uses the empty string <code>""</code>
+as a name for all upvalues.
+(For Lua functions,
+upvalues are the external local variables that the function uses,
+and that are consequently included in its closure.)
+
+
+<p>
+Upvalues have no particular order,
+as they are active through the whole function.
+They are numbered in an arbitrary order.
+
+
+
+
+
+<hr><h3><a name="lua_Hook"><code>lua_Hook</code></a></h3>
+<pre>typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);</pre>
+
+<p>
+Type for debugging hook functions.
+
+
+<p>
+Whenever a hook is called, its <code>ar</code> argument has its field
+<code>event</code> set to the specific event that triggered the hook.
+Lua identifies these events with the following constants:
+<a name="pdf-LUA_HOOKCALL"><code>LUA_HOOKCALL</code></a>, <a name="pdf-LUA_HOOKRET"><code>LUA_HOOKRET</code></a>,
+<a name="pdf-LUA_HOOKTAILCALL"><code>LUA_HOOKTAILCALL</code></a>, <a name="pdf-LUA_HOOKLINE"><code>LUA_HOOKLINE</code></a>,
+and <a name="pdf-LUA_HOOKCOUNT"><code>LUA_HOOKCOUNT</code></a>.
+Moreover, for line events, the field <code>currentline</code> is also set.
+To get the value of any other field in <code>ar</code>,
+the hook must call <a href="#lua_getinfo"><code>lua_getinfo</code></a>.
+
+
+<p>
+For call events, <code>event</code> can be <code>LUA_HOOKCALL</code>,
+the normal value, or <code>LUA_HOOKTAILCALL</code>, for a tail call;
+in this case, there will be no corresponding return event.
+
+
+<p>
+While Lua is running a hook, it disables other calls to hooks.
+Therefore, if a hook calls back Lua to execute a function or a chunk,
+this execution occurs without any calls to hooks.
+
+
+<p>
+Hook functions cannot have continuations,
+that is, they cannot call <a href="#lua_yieldk"><code>lua_yieldk</code></a>,
+<a href="#lua_pcallk"><code>lua_pcallk</code></a>, or <a href="#lua_callk"><code>lua_callk</code></a> with a non-null <code>k</code>.
+
+
+<p>
+Hook functions can yield under the following conditions:
+Only count and line events can yield;
+to yield, a hook function must finish its execution
+calling <a href="#lua_yield"><code>lua_yield</code></a> with <code>nresults</code> equal to zero
+(that is, with no values).
+
+
+
+
+
+<hr><h3><a name="lua_sethook"><code>lua_sethook</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void lua_sethook (lua_State *L, lua_Hook f, int mask, int count);</pre>
+
+<p>
+Sets the debugging hook function.
+
+
+<p>
+Argument <code>f</code> is the hook function.
+<code>mask</code> specifies on which events the hook will be called:
+it is formed by a bitwise OR of the constants
+<a name="pdf-LUA_MASKCALL"><code>LUA_MASKCALL</code></a>,
+<a name="pdf-LUA_MASKRET"><code>LUA_MASKRET</code></a>,
+<a name="pdf-LUA_MASKLINE"><code>LUA_MASKLINE</code></a>,
+and <a name="pdf-LUA_MASKCOUNT"><code>LUA_MASKCOUNT</code></a>.
+The <code>count</code> argument is only meaningful when the mask
+includes <code>LUA_MASKCOUNT</code>.
+For each event, the hook is called as explained below:
+
+<ul>
+
+<li><b>The call hook: </b> is called when the interpreter calls a function.
+The hook is called just after Lua enters the new function,
+before the function gets its arguments.
+</li>
+
+<li><b>The return hook: </b> is called when the interpreter returns from a function.
+The hook is called just before Lua leaves the function.
+There is no standard way to access the values
+to be returned by the function.
+</li>
+
+<li><b>The line hook: </b> is called when the interpreter is about to
+start the execution of a new line of code,
+or when it jumps back in the code (even to the same line).
+(This event only happens while Lua is executing a Lua function.)
+</li>
+
+<li><b>The count hook: </b> is called after the interpreter executes every
+<code>count</code> instructions.
+(This event only happens while Lua is executing a Lua function.)
+</li>
+
+</ul>
+
+<p>
+A hook is disabled by setting <code>mask</code> to zero.
+
+
+
+
+
+<hr><h3><a name="lua_setlocal"><code>lua_setlocal</code></a></h3><p>
+<span class="apii">[-(0|1), +0, &ndash;]</span>
+<pre>const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);</pre>
+
+<p>
+Sets the value of a local variable of a given activation record.
+It assigns the value at the top of the stack
+to the variable and returns its name.
+It also pops the value from the stack.
+
+
+<p>
+Returns <code>NULL</code> (and pops nothing)
+when the index is greater than
+the number of active local variables.
+
+
+<p>
+Parameters <code>ar</code> and <code>n</code> are as in function <a href="#lua_getlocal"><code>lua_getlocal</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_setupvalue"><code>lua_setupvalue</code></a></h3><p>
+<span class="apii">[-(0|1), +0, &ndash;]</span>
+<pre>const char *lua_setupvalue (lua_State *L, int funcindex, int n);</pre>
+
+<p>
+Sets the value of a closure's upvalue.
+It assigns the value at the top of the stack
+to the upvalue and returns its name.
+It also pops the value from the stack.
+
+
+<p>
+Returns <code>NULL</code> (and pops nothing)
+when the index <code>n</code> is greater than the number of upvalues.
+
+
+<p>
+Parameters <code>funcindex</code> and <code>n</code> are as in function <a href="#lua_getupvalue"><code>lua_getupvalue</code></a>.
+
+
+
+
+
+<hr><h3><a name="lua_upvalueid"><code>lua_upvalueid</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void *lua_upvalueid (lua_State *L, int funcindex, int n);</pre>
+
+<p>
+Returns a unique identifier for the upvalue numbered <code>n</code>
+from the closure at index <code>funcindex</code>.
+
+
+<p>
+These unique identifiers allow a program to check whether different
+closures share upvalues.
+Lua closures that share an upvalue
+(that is, that access a same external local variable)
+will return identical ids for those upvalue indices.
+
+
+<p>
+Parameters <code>funcindex</code> and <code>n</code> are as in function <a href="#lua_getupvalue"><code>lua_getupvalue</code></a>,
+but <code>n</code> cannot be greater than the number of upvalues.
+
+
+
+
+
+<hr><h3><a name="lua_upvaluejoin"><code>lua_upvaluejoin</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void lua_upvaluejoin (lua_State *L, int funcindex1, int n1,
+                                    int funcindex2, int n2);</pre>
+
+<p>
+Make the <code>n1</code>-th upvalue of the Lua closure at index <code>funcindex1</code>
+refer to the <code>n2</code>-th upvalue of the Lua closure at index <code>funcindex2</code>.
+
+
+
+
+
+
+
+<h1>5 &ndash; <a name="5">The Auxiliary Library</a></h1>
+
+<p>
+
+The <em>auxiliary library</em> provides several convenient functions
+to interface C with Lua.
+While the basic API provides the primitive functions for all
+interactions between C and Lua,
+the auxiliary library provides higher-level functions for some
+common tasks.
+
+
+<p>
+All functions and types from the auxiliary library
+are defined in header file <code>lauxlib.h</code> and
+have a prefix <code>luaL_</code>.
+
+
+<p>
+All functions in the auxiliary library are built on
+top of the basic API,
+and so they provide nothing that cannot be done with that API.
+Nevertheless, the use of the auxiliary library ensures
+more consistency to your code.
+
+
+<p>
+Several functions in the auxiliary library use internally some
+extra stack slots.
+When a function in the auxiliary library uses less than five slots,
+it does not check the stack size;
+it simply assumes that there are enough slots.
+
+
+<p>
+Several functions in the auxiliary library are used to
+check C&nbsp;function arguments.
+Because the error message is formatted for arguments
+(e.g., "<code>bad argument #1</code>"),
+you should not use these functions for other stack values.
+
+
+<p>
+Functions called <code>luaL_check*</code>
+always raise an error if the check is not satisfied.
+
+
+
+<h2>5.1 &ndash; <a name="5.1">Functions and Types</a></h2>
+
+<p>
+Here we list all functions and types from the auxiliary library
+in alphabetical order.
+
+
+
+<hr><h3><a name="luaL_addchar"><code>luaL_addchar</code></a></h3><p>
+<span class="apii">[-?, +?, <em>m</em>]</span>
+<pre>void luaL_addchar (luaL_Buffer *B, char c);</pre>
+
+<p>
+Adds the byte <code>c</code> to the buffer <code>B</code>
+(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_addlstring"><code>luaL_addlstring</code></a></h3><p>
+<span class="apii">[-?, +?, <em>m</em>]</span>
+<pre>void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l);</pre>
+
+<p>
+Adds the string pointed to by <code>s</code> with length <code>l</code> to
+the buffer <code>B</code>
+(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>).
+The string can contain embedded zeros.
+
+
+
+
+
+<hr><h3><a name="luaL_addsize"><code>luaL_addsize</code></a></h3><p>
+<span class="apii">[-?, +?, &ndash;]</span>
+<pre>void luaL_addsize (luaL_Buffer *B, size_t n);</pre>
+
+<p>
+Adds to the buffer <code>B</code> (see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>)
+a string of length <code>n</code> previously copied to the
+buffer area (see <a href="#luaL_prepbuffer"><code>luaL_prepbuffer</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_addstring"><code>luaL_addstring</code></a></h3><p>
+<span class="apii">[-?, +?, <em>m</em>]</span>
+<pre>void luaL_addstring (luaL_Buffer *B, const char *s);</pre>
+
+<p>
+Adds the zero-terminated string pointed to by <code>s</code>
+to the buffer <code>B</code>
+(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_addvalue"><code>luaL_addvalue</code></a></h3><p>
+<span class="apii">[-1, +?, <em>m</em>]</span>
+<pre>void luaL_addvalue (luaL_Buffer *B);</pre>
+
+<p>
+Adds the value at the top of the stack
+to the buffer <code>B</code>
+(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>).
+Pops the value.
+
+
+<p>
+This is the only function on string buffers that can (and must)
+be called with an extra element on the stack,
+which is the value to be added to the buffer.
+
+
+
+
+
+<hr><h3><a name="luaL_argcheck"><code>luaL_argcheck</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>void luaL_argcheck (lua_State *L,
+                    int cond,
+                    int arg,
+                    const char *extramsg);</pre>
+
+<p>
+Checks whether <code>cond</code> is true.
+If it is not, raises an error with a standard message (see <a href="#luaL_argerror"><code>luaL_argerror</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_argerror"><code>luaL_argerror</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>int luaL_argerror (lua_State *L, int arg, const char *extramsg);</pre>
+
+<p>
+Raises an error reporting a problem with argument <code>arg</code>
+of the C function that called it,
+using a standard message
+that includes <code>extramsg</code> as a comment:
+
+<pre>
+     bad argument #<em>arg</em> to '<em>funcname</em>' (<em>extramsg</em>)
+</pre><p>
+This function never returns.
+
+
+
+
+
+<hr><h3><a name="luaL_Buffer"><code>luaL_Buffer</code></a></h3>
+<pre>typedef struct luaL_Buffer luaL_Buffer;</pre>
+
+<p>
+Type for a <em>string buffer</em>.
+
+
+<p>
+A string buffer allows C&nbsp;code to build Lua strings piecemeal.
+Its pattern of use is as follows:
+
+<ul>
+
+<li>First declare a variable <code>b</code> of type <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>.</li>
+
+<li>Then initialize it with a call <code>luaL_buffinit(L, &amp;b)</code>.</li>
+
+<li>
+Then add string pieces to the buffer calling any of
+the <code>luaL_add*</code> functions.
+</li>
+
+<li>
+Finish by calling <code>luaL_pushresult(&amp;b)</code>.
+This call leaves the final string on the top of the stack.
+</li>
+
+</ul>
+
+<p>
+If you know beforehand the total size of the resulting string,
+you can use the buffer like this:
+
+<ul>
+
+<li>First declare a variable <code>b</code> of type <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>.</li>
+
+<li>Then initialize it and preallocate a space of
+size <code>sz</code> with a call <code>luaL_buffinitsize(L, &amp;b, sz)</code>.</li>
+
+<li>Then copy the string into that space.</li>
+
+<li>
+Finish by calling <code>luaL_pushresultsize(&amp;b, sz)</code>,
+where <code>sz</code> is the total size of the resulting string
+copied into that space.
+</li>
+
+</ul>
+
+<p>
+During its normal operation,
+a string buffer uses a variable number of stack slots.
+So, while using a buffer, you cannot assume that you know where
+the top of the stack is.
+You can use the stack between successive calls to buffer operations
+as long as that use is balanced;
+that is,
+when you call a buffer operation,
+the stack is at the same level
+it was immediately after the previous buffer operation.
+(The only exception to this rule is <a href="#luaL_addvalue"><code>luaL_addvalue</code></a>.)
+After calling <a href="#luaL_pushresult"><code>luaL_pushresult</code></a> the stack is back to its
+level when the buffer was initialized,
+plus the final string on its top.
+
+
+
+
+
+<hr><h3><a name="luaL_buffinit"><code>luaL_buffinit</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void luaL_buffinit (lua_State *L, luaL_Buffer *B);</pre>
+
+<p>
+Initializes a buffer <code>B</code>.
+This function does not allocate any space;
+the buffer must be declared as a variable
+(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_buffinitsize"><code>luaL_buffinitsize</code></a></h3><p>
+<span class="apii">[-?, +?, <em>m</em>]</span>
+<pre>char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz);</pre>
+
+<p>
+Equivalent to the sequence
+<a href="#luaL_buffinit"><code>luaL_buffinit</code></a>, <a href="#luaL_prepbuffsize"><code>luaL_prepbuffsize</code></a>.
+
+
+
+
+
+<hr><h3><a name="luaL_callmeta"><code>luaL_callmeta</code></a></h3><p>
+<span class="apii">[-0, +(0|1), <em>e</em>]</span>
+<pre>int luaL_callmeta (lua_State *L, int obj, const char *e);</pre>
+
+<p>
+Calls a metamethod.
+
+
+<p>
+If the object at index <code>obj</code> has a metatable and this
+metatable has a field <code>e</code>,
+this function calls this field passing the object as its only argument.
+In this case this function returns true and pushes onto the
+stack the value returned by the call.
+If there is no metatable or no metamethod,
+this function returns false (without pushing any value on the stack).
+
+
+
+
+
+<hr><h3><a name="luaL_checkany"><code>luaL_checkany</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>void luaL_checkany (lua_State *L, int arg);</pre>
+
+<p>
+Checks whether the function has an argument
+of any type (including <b>nil</b>) at position <code>arg</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_checkinteger"><code>luaL_checkinteger</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>lua_Integer luaL_checkinteger (lua_State *L, int arg);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> is an integer
+(or can be converted to an integer)
+and returns this integer cast to a <a href="#lua_Integer"><code>lua_Integer</code></a>.
+
+
+
+
+
+<hr><h3><a name="luaL_checklstring"><code>luaL_checklstring</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>const char *luaL_checklstring (lua_State *L, int arg, size_t *l);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> is a string
+and returns this string;
+if <code>l</code> is not <code>NULL</code> fills <code>*l</code>
+with the string's length.
+
+
+<p>
+This function uses <a href="#lua_tolstring"><code>lua_tolstring</code></a> to get its result,
+so all conversions and caveats of that function apply here.
+
+
+
+
+
+<hr><h3><a name="luaL_checknumber"><code>luaL_checknumber</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>lua_Number luaL_checknumber (lua_State *L, int arg);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> is a number
+and returns this number.
+
+
+
+
+
+<hr><h3><a name="luaL_checkoption"><code>luaL_checkoption</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>int luaL_checkoption (lua_State *L,
+                      int arg,
+                      const char *def,
+                      const char *const lst[]);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> is a string and
+searches for this string in the array <code>lst</code>
+(which must be NULL-terminated).
+Returns the index in the array where the string was found.
+Raises an error if the argument is not a string or
+if the string cannot be found.
+
+
+<p>
+If <code>def</code> is not <code>NULL</code>,
+the function uses <code>def</code> as a default value when
+there is no argument <code>arg</code> or when this argument is <b>nil</b>.
+
+
+<p>
+This is a useful function for mapping strings to C&nbsp;enums.
+(The usual convention in Lua libraries is
+to use strings instead of numbers to select options.)
+
+
+
+
+
+<hr><h3><a name="luaL_checkstack"><code>luaL_checkstack</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>void luaL_checkstack (lua_State *L, int sz, const char *msg);</pre>
+
+<p>
+Grows the stack size to <code>top + sz</code> elements,
+raising an error if the stack cannot grow to that size.
+<code>msg</code> is an additional text to go into the error message
+(or <code>NULL</code> for no additional text).
+
+
+
+
+
+<hr><h3><a name="luaL_checkstring"><code>luaL_checkstring</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>const char *luaL_checkstring (lua_State *L, int arg);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> is a string
+and returns this string.
+
+
+<p>
+This function uses <a href="#lua_tolstring"><code>lua_tolstring</code></a> to get its result,
+so all conversions and caveats of that function apply here.
+
+
+
+
+
+<hr><h3><a name="luaL_checktype"><code>luaL_checktype</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>void luaL_checktype (lua_State *L, int arg, int t);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> has type <code>t</code>.
+See <a href="#lua_type"><code>lua_type</code></a> for the encoding of types for <code>t</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_checkudata"><code>luaL_checkudata</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>void *luaL_checkudata (lua_State *L, int arg, const char *tname);</pre>
+
+<p>
+Checks whether the function argument <code>arg</code> is a userdata
+of the type <code>tname</code> (see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>) and
+returns the userdata address (see <a href="#lua_touserdata"><code>lua_touserdata</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_checkversion"><code>luaL_checkversion</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>void luaL_checkversion (lua_State *L);</pre>
+
+<p>
+Checks whether the core running the call,
+the core that created the Lua state,
+and the code making the call are all using the same version of Lua.
+Also checks whether the core running the call
+and the core that created the Lua state
+are using the same address space.
+
+
+
+
+
+<hr><h3><a name="luaL_dofile"><code>luaL_dofile</code></a></h3><p>
+<span class="apii">[-0, +?, <em>e</em>]</span>
+<pre>int luaL_dofile (lua_State *L, const char *filename);</pre>
+
+<p>
+Loads and runs the given file.
+It is defined as the following macro:
+
+<pre>
+     (luaL_loadfile(L, filename) || lua_pcall(L, 0, LUA_MULTRET, 0))
+</pre><p>
+It returns false if there are no errors
+or true in case of errors.
+
+
+
+
+
+<hr><h3><a name="luaL_dostring"><code>luaL_dostring</code></a></h3><p>
+<span class="apii">[-0, +?, &ndash;]</span>
+<pre>int luaL_dostring (lua_State *L, const char *str);</pre>
+
+<p>
+Loads and runs the given string.
+It is defined as the following macro:
+
+<pre>
+     (luaL_loadstring(L, str) || lua_pcall(L, 0, LUA_MULTRET, 0))
+</pre><p>
+It returns false if there are no errors
+or true in case of errors.
+
+
+
+
+
+<hr><h3><a name="luaL_error"><code>luaL_error</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>int luaL_error (lua_State *L, const char *fmt, ...);</pre>
+
+<p>
+Raises an error.
+The error message format is given by <code>fmt</code>
+plus any extra arguments,
+following the same rules of <a href="#lua_pushfstring"><code>lua_pushfstring</code></a>.
+It also adds at the beginning of the message the file name and
+the line number where the error occurred,
+if this information is available.
+
+
+<p>
+This function never returns,
+but it is an idiom to use it in C&nbsp;functions
+as <code>return luaL_error(<em>args</em>)</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_execresult"><code>luaL_execresult</code></a></h3><p>
+<span class="apii">[-0, +3, <em>m</em>]</span>
+<pre>int luaL_execresult (lua_State *L, int stat);</pre>
+
+<p>
+This function produces the return values for
+process-related functions in the standard library
+(<a href="#pdf-os.execute"><code>os.execute</code></a> and <a href="#pdf-io.close"><code>io.close</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_fileresult"><code>luaL_fileresult</code></a></h3><p>
+<span class="apii">[-0, +(1|3), <em>m</em>]</span>
+<pre>int luaL_fileresult (lua_State *L, int stat, const char *fname);</pre>
+
+<p>
+This function produces the return values for
+file-related functions in the standard library
+(<a href="#pdf-io.open"><code>io.open</code></a>, <a href="#pdf-os.rename"><code>os.rename</code></a>, <a href="#pdf-file:seek"><code>file:seek</code></a>, etc.).
+
+
+
+
+
+<hr><h3><a name="luaL_getmetafield"><code>luaL_getmetafield</code></a></h3><p>
+<span class="apii">[-0, +(0|1), <em>m</em>]</span>
+<pre>int luaL_getmetafield (lua_State *L, int obj, const char *e);</pre>
+
+<p>
+Pushes onto the stack the field <code>e</code> from the metatable
+of the object at index <code>obj</code> and returns the type of pushed value.
+If the object does not have a metatable,
+or if the metatable does not have this field,
+pushes nothing and returns <code>LUA_TNIL</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_getmetatable"><code>luaL_getmetatable</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>int luaL_getmetatable (lua_State *L, const char *tname);</pre>
+
+<p>
+Pushes onto the stack the metatable associated with name <code>tname</code>
+in the registry (see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>)
+(<b>nil</b> if there is no metatable associated with that name).
+Returns the type of the pushed value.
+
+
+
+
+
+<hr><h3><a name="luaL_getsubtable"><code>luaL_getsubtable</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>int luaL_getsubtable (lua_State *L, int idx, const char *fname);</pre>
+
+<p>
+Ensures that the value <code>t[fname]</code>,
+where <code>t</code> is the value at index <code>idx</code>,
+is a table,
+and pushes that table onto the stack.
+Returns true if it finds a previous table there
+and false if it creates a new table.
+
+
+
+
+
+<hr><h3><a name="luaL_gsub"><code>luaL_gsub</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>const char *luaL_gsub (lua_State *L,
+                       const char *s,
+                       const char *p,
+                       const char *r);</pre>
+
+<p>
+Creates a copy of string <code>s</code> by replacing
+any occurrence of the string <code>p</code>
+with the string <code>r</code>.
+Pushes the resulting string on the stack and returns it.
+
+
+
+
+
+<hr><h3><a name="luaL_len"><code>luaL_len</code></a></h3><p>
+<span class="apii">[-0, +0, <em>e</em>]</span>
+<pre>lua_Integer luaL_len (lua_State *L, int index);</pre>
+
+<p>
+Returns the "length" of the value at the given index
+as a number;
+it is equivalent to the '<code>#</code>' operator in Lua (see <a href="#3.4.7">&sect;3.4.7</a>).
+Raises an error if the result of the operation is not an integer.
+(This case only can happen through metamethods.)
+
+
+
+
+
+<hr><h3><a name="luaL_loadbuffer"><code>luaL_loadbuffer</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int luaL_loadbuffer (lua_State *L,
+                     const char *buff,
+                     size_t sz,
+                     const char *name);</pre>
+
+<p>
+Equivalent to <a href="#luaL_loadbufferx"><code>luaL_loadbufferx</code></a> with <code>mode</code> equal to <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_loadbufferx"><code>luaL_loadbufferx</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int luaL_loadbufferx (lua_State *L,
+                      const char *buff,
+                      size_t sz,
+                      const char *name,
+                      const char *mode);</pre>
+
+<p>
+Loads a buffer as a Lua chunk.
+This function uses <a href="#lua_load"><code>lua_load</code></a> to load the chunk in the
+buffer pointed to by <code>buff</code> with size <code>sz</code>.
+
+
+<p>
+This function returns the same results as <a href="#lua_load"><code>lua_load</code></a>.
+<code>name</code> is the chunk name,
+used for debug information and error messages.
+The string <code>mode</code> works as in function <a href="#lua_load"><code>lua_load</code></a>.
+
+
+
+
+
+<hr><h3><a name="luaL_loadfile"><code>luaL_loadfile</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>int luaL_loadfile (lua_State *L, const char *filename);</pre>
+
+<p>
+Equivalent to <a href="#luaL_loadfilex"><code>luaL_loadfilex</code></a> with <code>mode</code> equal to <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_loadfilex"><code>luaL_loadfilex</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>int luaL_loadfilex (lua_State *L, const char *filename,
+                                            const char *mode);</pre>
+
+<p>
+Loads a file as a Lua chunk.
+This function uses <a href="#lua_load"><code>lua_load</code></a> to load the chunk in the file
+named <code>filename</code>.
+If <code>filename</code> is <code>NULL</code>,
+then it loads from the standard input.
+The first line in the file is ignored if it starts with a <code>#</code>.
+
+
+<p>
+The string <code>mode</code> works as in function <a href="#lua_load"><code>lua_load</code></a>.
+
+
+<p>
+This function returns the same results as <a href="#lua_load"><code>lua_load</code></a>,
+but it has an extra error code <a name="pdf-LUA_ERRFILE"><code>LUA_ERRFILE</code></a>
+if it cannot open/read the file or the file has a wrong mode.
+
+
+<p>
+As <a href="#lua_load"><code>lua_load</code></a>, this function only loads the chunk;
+it does not run it.
+
+
+
+
+
+<hr><h3><a name="luaL_loadstring"><code>luaL_loadstring</code></a></h3><p>
+<span class="apii">[-0, +1, &ndash;]</span>
+<pre>int luaL_loadstring (lua_State *L, const char *s);</pre>
+
+<p>
+Loads a string as a Lua chunk.
+This function uses <a href="#lua_load"><code>lua_load</code></a> to load the chunk in
+the zero-terminated string <code>s</code>.
+
+
+<p>
+This function returns the same results as <a href="#lua_load"><code>lua_load</code></a>.
+
+
+<p>
+Also as <a href="#lua_load"><code>lua_load</code></a>, this function only loads the chunk;
+it does not run it.
+
+
+
+
+
+<hr><h3><a name="luaL_newlib"><code>luaL_newlib</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void luaL_newlib (lua_State *L, const luaL_Reg l[]);</pre>
+
+<p>
+Creates a new table and registers there
+the functions in list <code>l</code>.
+
+
+<p>
+It is implemented as the following macro:
+
+<pre>
+     (luaL_newlibtable(L,l), luaL_setfuncs(L,l,0))
+</pre><p>
+The array <code>l</code> must be the actual array,
+not a pointer to it.
+
+
+
+
+
+<hr><h3><a name="luaL_newlibtable"><code>luaL_newlibtable</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void luaL_newlibtable (lua_State *L, const luaL_Reg l[]);</pre>
+
+<p>
+Creates a new table with a size optimized
+to store all entries in the array <code>l</code>
+(but does not actually store them).
+It is intended to be used in conjunction with <a href="#luaL_setfuncs"><code>luaL_setfuncs</code></a>
+(see <a href="#luaL_newlib"><code>luaL_newlib</code></a>).
+
+
+<p>
+It is implemented as a macro.
+The array <code>l</code> must be the actual array,
+not a pointer to it.
+
+
+
+
+
+<hr><h3><a name="luaL_newmetatable"><code>luaL_newmetatable</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>int luaL_newmetatable (lua_State *L, const char *tname);</pre>
+
+<p>
+If the registry already has the key <code>tname</code>,
+returns 0.
+Otherwise,
+creates a new table to be used as a metatable for userdata,
+adds to this new table the pair <code>__name = tname</code>,
+adds to the registry the pair <code>[tname] = new table</code>,
+and returns 1.
+(The entry <code>__name</code> is used by some error-reporting functions.)
+
+
+<p>
+In both cases pushes onto the stack the final value associated
+with <code>tname</code> in the registry.
+
+
+
+
+
+<hr><h3><a name="luaL_newstate"><code>luaL_newstate</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>lua_State *luaL_newstate (void);</pre>
+
+<p>
+Creates a new Lua state.
+It calls <a href="#lua_newstate"><code>lua_newstate</code></a> with an
+allocator based on the standard&nbsp;C <code>realloc</code> function
+and then sets a panic function (see <a href="#4.6">&sect;4.6</a>) that prints
+an error message to the standard error output in case of fatal
+errors.
+
+
+<p>
+Returns the new state,
+or <code>NULL</code> if there is a memory allocation error.
+
+
+
+
+
+<hr><h3><a name="luaL_openlibs"><code>luaL_openlibs</code></a></h3><p>
+<span class="apii">[-0, +0, <em>e</em>]</span>
+<pre>void luaL_openlibs (lua_State *L);</pre>
+
+<p>
+Opens all standard Lua libraries into the given state.
+
+
+
+
+
+<hr><h3><a name="luaL_opt"><code>luaL_opt</code></a></h3><p>
+<span class="apii">[-0, +0, <em>e</em>]</span>
+<pre>T luaL_opt (L, func, arg, dflt);</pre>
+
+<p>
+This macro is defined as follows:
+
+<pre>
+     (lua_isnoneornil(L,(arg)) ? (dflt) : func(L,(arg)))
+</pre><p>
+In words, if the argument <code>arg</code> is nil or absent,
+the macro results in the default <code>dflt</code>.
+Otherwise, it results in the result of calling <code>func</code>
+with the state <code>L</code> and the argument index <code>arg</code> as
+parameters.
+Note that it evaluates the expression <code>dflt</code> only if needed.
+
+
+
+
+
+<hr><h3><a name="luaL_optinteger"><code>luaL_optinteger</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>lua_Integer luaL_optinteger (lua_State *L,
+                             int arg,
+                             lua_Integer d);</pre>
+
+<p>
+If the function argument <code>arg</code> is an integer
+(or convertible to an integer),
+returns this integer.
+If this argument is absent or is <b>nil</b>,
+returns <code>d</code>.
+Otherwise, raises an error.
+
+
+
+
+
+<hr><h3><a name="luaL_optlstring"><code>luaL_optlstring</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>const char *luaL_optlstring (lua_State *L,
+                             int arg,
+                             const char *d,
+                             size_t *l);</pre>
+
+<p>
+If the function argument <code>arg</code> is a string,
+returns this string.
+If this argument is absent or is <b>nil</b>,
+returns <code>d</code>.
+Otherwise, raises an error.
+
+
+<p>
+If <code>l</code> is not <code>NULL</code>,
+fills the position <code>*l</code> with the result's length.
+If the result is <code>NULL</code>
+(only possible when returning <code>d</code> and <code>d == NULL</code>),
+its length is considered zero.
+
+
+
+
+
+<hr><h3><a name="luaL_optnumber"><code>luaL_optnumber</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number d);</pre>
+
+<p>
+If the function argument <code>arg</code> is a number,
+returns this number.
+If this argument is absent or is <b>nil</b>,
+returns <code>d</code>.
+Otherwise, raises an error.
+
+
+
+
+
+<hr><h3><a name="luaL_optstring"><code>luaL_optstring</code></a></h3><p>
+<span class="apii">[-0, +0, <em>v</em>]</span>
+<pre>const char *luaL_optstring (lua_State *L,
+                            int arg,
+                            const char *d);</pre>
+
+<p>
+If the function argument <code>arg</code> is a string,
+returns this string.
+If this argument is absent or is <b>nil</b>,
+returns <code>d</code>.
+Otherwise, raises an error.
+
+
+
+
+
+<hr><h3><a name="luaL_prepbuffer"><code>luaL_prepbuffer</code></a></h3><p>
+<span class="apii">[-?, +?, <em>m</em>]</span>
+<pre>char *luaL_prepbuffer (luaL_Buffer *B);</pre>
+
+<p>
+Equivalent to <a href="#luaL_prepbuffsize"><code>luaL_prepbuffsize</code></a>
+with the predefined size <a name="pdf-LUAL_BUFFERSIZE"><code>LUAL_BUFFERSIZE</code></a>.
+
+
+
+
+
+<hr><h3><a name="luaL_prepbuffsize"><code>luaL_prepbuffsize</code></a></h3><p>
+<span class="apii">[-?, +?, <em>m</em>]</span>
+<pre>char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz);</pre>
+
+<p>
+Returns an address to a space of size <code>sz</code>
+where you can copy a string to be added to buffer <code>B</code>
+(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>).
+After copying the string into this space you must call
+<a href="#luaL_addsize"><code>luaL_addsize</code></a> with the size of the string to actually add
+it to the buffer.
+
+
+
+
+
+<hr><h3><a name="luaL_pushresult"><code>luaL_pushresult</code></a></h3><p>
+<span class="apii">[-?, +1, <em>m</em>]</span>
+<pre>void luaL_pushresult (luaL_Buffer *B);</pre>
+
+<p>
+Finishes the use of buffer <code>B</code> leaving the final string on
+the top of the stack.
+
+
+
+
+
+<hr><h3><a name="luaL_pushresultsize"><code>luaL_pushresultsize</code></a></h3><p>
+<span class="apii">[-?, +1, <em>m</em>]</span>
+<pre>void luaL_pushresultsize (luaL_Buffer *B, size_t sz);</pre>
+
+<p>
+Equivalent to the sequence <a href="#luaL_addsize"><code>luaL_addsize</code></a>, <a href="#luaL_pushresult"><code>luaL_pushresult</code></a>.
+
+
+
+
+
+<hr><h3><a name="luaL_ref"><code>luaL_ref</code></a></h3><p>
+<span class="apii">[-1, +0, <em>m</em>]</span>
+<pre>int luaL_ref (lua_State *L, int t);</pre>
+
+<p>
+Creates and returns a <em>reference</em>,
+in the table at index <code>t</code>,
+for the object at the top of the stack (and pops the object).
+
+
+<p>
+A reference is a unique integer key.
+As long as you do not manually add integer keys into table <code>t</code>,
+<a href="#luaL_ref"><code>luaL_ref</code></a> ensures the uniqueness of the key it returns.
+You can retrieve an object referred by reference <code>r</code>
+by calling <code>lua_rawgeti(L, t, r)</code>.
+Function <a href="#luaL_unref"><code>luaL_unref</code></a> frees a reference and its associated object.
+
+
+<p>
+If the object at the top of the stack is <b>nil</b>,
+<a href="#luaL_ref"><code>luaL_ref</code></a> returns the constant <a name="pdf-LUA_REFNIL"><code>LUA_REFNIL</code></a>.
+The constant <a name="pdf-LUA_NOREF"><code>LUA_NOREF</code></a> is guaranteed to be different
+from any reference returned by <a href="#luaL_ref"><code>luaL_ref</code></a>.
+
+
+
+
+
+<hr><h3><a name="luaL_Reg"><code>luaL_Reg</code></a></h3>
+<pre>typedef struct luaL_Reg {
+  const char *name;
+  lua_CFunction func;
+} luaL_Reg;</pre>
+
+<p>
+Type for arrays of functions to be registered by
+<a href="#luaL_setfuncs"><code>luaL_setfuncs</code></a>.
+<code>name</code> is the function name and <code>func</code> is a pointer to
+the function.
+Any array of <a href="#luaL_Reg"><code>luaL_Reg</code></a> must end with a sentinel entry
+in which both <code>name</code> and <code>func</code> are <code>NULL</code>.
+
+
+
+
+
+<hr><h3><a name="luaL_requiref"><code>luaL_requiref</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>void luaL_requiref (lua_State *L, const char *modname,
+                    lua_CFunction openf, int glb);</pre>
+
+<p>
+If <code>modname</code> is not already present in <a href="#pdf-package.loaded"><code>package.loaded</code></a>,
+calls function <code>openf</code> with string <code>modname</code> as an argument
+and sets the call result in <code>package.loaded[modname]</code>,
+as if that function has been called through <a href="#pdf-require"><code>require</code></a>.
+
+
+<p>
+If <code>glb</code> is true,
+also stores the module into global <code>modname</code>.
+
+
+<p>
+Leaves a copy of the module on the stack.
+
+
+
+
+
+<hr><h3><a name="luaL_setfuncs"><code>luaL_setfuncs</code></a></h3><p>
+<span class="apii">[-nup, +0, <em>m</em>]</span>
+<pre>void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);</pre>
+
+<p>
+Registers all functions in the array <code>l</code>
+(see <a href="#luaL_Reg"><code>luaL_Reg</code></a>) into the table on the top of the stack
+(below optional upvalues, see next).
+
+
+<p>
+When <code>nup</code> is not zero,
+all functions are created sharing <code>nup</code> upvalues,
+which must be previously pushed on the stack
+on top of the library table.
+These values are popped from the stack after the registration.
+
+
+
+
+
+<hr><h3><a name="luaL_setmetatable"><code>luaL_setmetatable</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void luaL_setmetatable (lua_State *L, const char *tname);</pre>
+
+<p>
+Sets the metatable of the object at the top of the stack
+as the metatable associated with name <code>tname</code>
+in the registry (see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>).
+
+
+
+
+
+<hr><h3><a name="luaL_Stream"><code>luaL_Stream</code></a></h3>
+<pre>typedef struct luaL_Stream {
+  FILE *f;
+  lua_CFunction closef;
+} luaL_Stream;</pre>
+
+<p>
+The standard representation for file handles,
+which is used by the standard I/O library.
+
+
+<p>
+A file handle is implemented as a full userdata,
+with a metatable called <code>LUA_FILEHANDLE</code>
+(where <code>LUA_FILEHANDLE</code> is a macro with the actual metatable's name).
+The metatable is created by the I/O library
+(see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>).
+
+
+<p>
+This userdata must start with the structure <code>luaL_Stream</code>;
+it can contain other data after this initial structure.
+Field <code>f</code> points to the corresponding C stream
+(or it can be <code>NULL</code> to indicate an incompletely created handle).
+Field <code>closef</code> points to a Lua function
+that will be called to close the stream
+when the handle is closed or collected;
+this function receives the file handle as its sole argument and
+must return either <b>true</b> (in case of success)
+or <b>nil</b> plus an error message (in case of error).
+Once Lua calls this field,
+it changes the field value to <code>NULL</code>
+to signal that the handle is closed.
+
+
+
+
+
+<hr><h3><a name="luaL_testudata"><code>luaL_testudata</code></a></h3><p>
+<span class="apii">[-0, +0, <em>m</em>]</span>
+<pre>void *luaL_testudata (lua_State *L, int arg, const char *tname);</pre>
+
+<p>
+This function works like <a href="#luaL_checkudata"><code>luaL_checkudata</code></a>,
+except that, when the test fails,
+it returns <code>NULL</code> instead of raising an error.
+
+
+
+
+
+<hr><h3><a name="luaL_tolstring"><code>luaL_tolstring</code></a></h3><p>
+<span class="apii">[-0, +1, <em>e</em>]</span>
+<pre>const char *luaL_tolstring (lua_State *L, int idx, size_t *len);</pre>
+
+<p>
+Converts any Lua value at the given index to a C&nbsp;string
+in a reasonable format.
+The resulting string is pushed onto the stack and also
+returned by the function.
+If <code>len</code> is not <code>NULL</code>,
+the function also sets <code>*len</code> with the string length.
+
+
+<p>
+If the value has a metatable with a <code>__tostring</code> field,
+then <code>luaL_tolstring</code> calls the corresponding metamethod
+with the value as argument,
+and uses the result of the call as its result.
+
+
+
+
+
+<hr><h3><a name="luaL_traceback"><code>luaL_traceback</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void luaL_traceback (lua_State *L, lua_State *L1, const char *msg,
+                     int level);</pre>
+
+<p>
+Creates and pushes a traceback of the stack <code>L1</code>.
+If <code>msg</code> is not <code>NULL</code> it is appended
+at the beginning of the traceback.
+The <code>level</code> parameter tells at which level
+to start the traceback.
+
+
+
+
+
+<hr><h3><a name="luaL_typename"><code>luaL_typename</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>const char *luaL_typename (lua_State *L, int index);</pre>
+
+<p>
+Returns the name of the type of the value at the given index.
+
+
+
+
+
+<hr><h3><a name="luaL_unref"><code>luaL_unref</code></a></h3><p>
+<span class="apii">[-0, +0, &ndash;]</span>
+<pre>void luaL_unref (lua_State *L, int t, int ref);</pre>
+
+<p>
+Releases reference <code>ref</code> from the table at index <code>t</code>
+(see <a href="#luaL_ref"><code>luaL_ref</code></a>).
+The entry is removed from the table,
+so that the referred object can be collected.
+The reference <code>ref</code> is also freed to be used again.
+
+
+<p>
+If <code>ref</code> is <a href="#pdf-LUA_NOREF"><code>LUA_NOREF</code></a> or <a href="#pdf-LUA_REFNIL"><code>LUA_REFNIL</code></a>,
+<a href="#luaL_unref"><code>luaL_unref</code></a> does nothing.
+
+
+
+
+
+<hr><h3><a name="luaL_where"><code>luaL_where</code></a></h3><p>
+<span class="apii">[-0, +1, <em>m</em>]</span>
+<pre>void luaL_where (lua_State *L, int lvl);</pre>
+
+<p>
+Pushes onto the stack a string identifying the current position
+of the control at level <code>lvl</code> in the call stack.
+Typically this string has the following format:
+
+<pre>
+     <em>chunkname</em>:<em>currentline</em>:
+</pre><p>
+Level&nbsp;0 is the running function,
+level&nbsp;1 is the function that called the running function,
+etc.
+
+
+<p>
+This function is used to build a prefix for error messages.
+
+
+
+
+
+
+
+<h1>6 &ndash; <a name="6">Standard Libraries</a></h1>
+
+<p>
+The standard Lua libraries provide useful functions
+that are implemented directly through the C&nbsp;API.
+Some of these functions provide essential services to the language
+(e.g., <a href="#pdf-type"><code>type</code></a> and <a href="#pdf-getmetatable"><code>getmetatable</code></a>);
+others provide access to "outside" services (e.g., I/O);
+and others could be implemented in Lua itself,
+but are quite useful or have critical performance requirements that
+deserve an implementation in C (e.g., <a href="#pdf-table.sort"><code>table.sort</code></a>).
+
+
+<p>
+All libraries are implemented through the official C&nbsp;API
+and are provided as separate C&nbsp;modules.
+Currently, Lua has the following standard libraries:
+
+<ul>
+
+<li>basic library (<a href="#6.1">&sect;6.1</a>);</li>
+
+<li>coroutine library (<a href="#6.2">&sect;6.2</a>);</li>
+
+<li>package library (<a href="#6.3">&sect;6.3</a>);</li>
+
+<li>string manipulation (<a href="#6.4">&sect;6.4</a>);</li>
+
+<li>basic UTF-8 support (<a href="#6.5">&sect;6.5</a>);</li>
+
+<li>table manipulation (<a href="#6.6">&sect;6.6</a>);</li>
+
+<li>mathematical functions (<a href="#6.7">&sect;6.7</a>) (sin, log, etc.);</li>
+
+<li>input and output (<a href="#6.8">&sect;6.8</a>);</li>
+
+<li>operating system facilities (<a href="#6.9">&sect;6.9</a>);</li>
+
+<li>debug facilities (<a href="#6.10">&sect;6.10</a>).</li>
+
+</ul><p>
+Except for the basic and the package libraries,
+each library provides all its functions as fields of a global table
+or as methods of its objects.
+
+
+<p>
+To have access to these libraries,
+the C&nbsp;host program should call the <a href="#luaL_openlibs"><code>luaL_openlibs</code></a> function,
+which opens all standard libraries.
+Alternatively,
+the host program can open them individually by using
+<a href="#luaL_requiref"><code>luaL_requiref</code></a> to call
+<a name="pdf-luaopen_base"><code>luaopen_base</code></a> (for the basic library),
+<a name="pdf-luaopen_package"><code>luaopen_package</code></a> (for the package library),
+<a name="pdf-luaopen_coroutine"><code>luaopen_coroutine</code></a> (for the coroutine library),
+<a name="pdf-luaopen_string"><code>luaopen_string</code></a> (for the string library),
+<a name="pdf-luaopen_utf8"><code>luaopen_utf8</code></a> (for the UTF8 library),
+<a name="pdf-luaopen_table"><code>luaopen_table</code></a> (for the table library),
+<a name="pdf-luaopen_math"><code>luaopen_math</code></a> (for the mathematical library),
+<a name="pdf-luaopen_io"><code>luaopen_io</code></a> (for the I/O library),
+<a name="pdf-luaopen_os"><code>luaopen_os</code></a> (for the operating system library),
+and <a name="pdf-luaopen_debug"><code>luaopen_debug</code></a> (for the debug library).
+These functions are declared in <a name="pdf-lualib.h"><code>lualib.h</code></a>.
+
+
+
+<h2>6.1 &ndash; <a name="6.1">Basic Functions</a></h2>
+
+<p>
+The basic library provides core functions to Lua.
+If you do not include this library in your application,
+you should check carefully whether you need to provide
+implementations for some of its facilities.
+
+
+<p>
+<hr><h3><a name="pdf-assert"><code>assert (v [, message])</code></a></h3>
+
+
+<p>
+Calls <a href="#pdf-error"><code>error</code></a> if
+the value of its argument <code>v</code> is false (i.e., <b>nil</b> or <b>false</b>);
+otherwise, returns all its arguments.
+In case of error,
+<code>message</code> is the error object;
+when absent, it defaults to "<code>assertion failed!</code>"
+
+
+
+
+<p>
+<hr><h3><a name="pdf-collectgarbage"><code>collectgarbage ([opt [, arg]])</code></a></h3>
+
+
+<p>
+This function is a generic interface to the garbage collector.
+It performs different functions according to its first argument, <code>opt</code>:
+
+<ul>
+
+<li><b>"<code>collect</code>": </b>
+performs a full garbage-collection cycle.
+This is the default option.
+</li>
+
+<li><b>"<code>stop</code>": </b>
+stops automatic execution of the garbage collector.
+The collector will run only when explicitly invoked,
+until a call to restart it.
+</li>
+
+<li><b>"<code>restart</code>": </b>
+restarts automatic execution of the garbage collector.
+</li>
+
+<li><b>"<code>count</code>": </b>
+returns the total memory in use by Lua in Kbytes.
+The value has a fractional part,
+so that it multiplied by 1024
+gives the exact number of bytes in use by Lua
+(except for overflows).
+</li>
+
+<li><b>"<code>step</code>": </b>
+performs a garbage-collection step.
+The step "size" is controlled by <code>arg</code>.
+With a zero value,
+the collector will perform one basic (indivisible) step.
+For non-zero values,
+the collector will perform as if that amount of memory
+(in KBytes) had been allocated by Lua.
+Returns <b>true</b> if the step finished a collection cycle.
+</li>
+
+<li><b>"<code>setpause</code>": </b>
+sets <code>arg</code> as the new value for the <em>pause</em> of
+the collector (see <a href="#2.5">&sect;2.5</a>).
+Returns the previous value for <em>pause</em>.
+</li>
+
+<li><b>"<code>setstepmul</code>": </b>
+sets <code>arg</code> as the new value for the <em>step multiplier</em> of
+the collector (see <a href="#2.5">&sect;2.5</a>).
+Returns the previous value for <em>step</em>.
+</li>
+
+<li><b>"<code>isrunning</code>": </b>
+returns a boolean that tells whether the collector is running
+(i.e., not stopped).
+</li>
+
+</ul>
+
+
+
+<p>
+<hr><h3><a name="pdf-dofile"><code>dofile ([filename])</code></a></h3>
+Opens the named file and executes its contents as a Lua chunk.
+When called without arguments,
+<code>dofile</code> executes the contents of the standard input (<code>stdin</code>).
+Returns all values returned by the chunk.
+In case of errors, <code>dofile</code> propagates the error
+to its caller (that is, <code>dofile</code> does not run in protected mode).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-error"><code>error (message [, level])</code></a></h3>
+Terminates the last protected function called
+and returns <code>message</code> as the error object.
+Function <code>error</code> never returns.
+
+
+<p>
+Usually, <code>error</code> adds some information about the error position
+at the beginning of the message, if the message is a string.
+The <code>level</code> argument specifies how to get the error position.
+With level&nbsp;1 (the default), the error position is where the
+<code>error</code> function was called.
+Level&nbsp;2 points the error to where the function
+that called <code>error</code> was called; and so on.
+Passing a level&nbsp;0 avoids the addition of error position information
+to the message.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-_G"><code>_G</code></a></h3>
+A global variable (not a function) that
+holds the global environment (see <a href="#2.2">&sect;2.2</a>).
+Lua itself does not use this variable;
+changing its value does not affect any environment,
+nor vice versa.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-getmetatable"><code>getmetatable (object)</code></a></h3>
+
+
+<p>
+If <code>object</code> does not have a metatable, returns <b>nil</b>.
+Otherwise,
+if the object's metatable has a <code>__metatable</code> field,
+returns the associated value.
+Otherwise, returns the metatable of the given object.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-ipairs"><code>ipairs (t)</code></a></h3>
+
+
+<p>
+Returns three values (an iterator function, the table <code>t</code>, and 0)
+so that the construction
+
+<pre>
+     for i,v in ipairs(t) do <em>body</em> end
+</pre><p>
+will iterate over the key&ndash;value pairs
+(<code>1,t[1]</code>), (<code>2,t[2]</code>), ...,
+up to the first nil value.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-load"><code>load (chunk [, chunkname [, mode [, env]]])</code></a></h3>
+
+
+<p>
+Loads a chunk.
+
+
+<p>
+If <code>chunk</code> is a string, the chunk is this string.
+If <code>chunk</code> is a function,
+<code>load</code> calls it repeatedly to get the chunk pieces.
+Each call to <code>chunk</code> must return a string that concatenates
+with previous results.
+A return of an empty string, <b>nil</b>, or no value signals the end of the chunk.
+
+
+<p>
+If there are no syntactic errors,
+returns the compiled chunk as a function;
+otherwise, returns <b>nil</b> plus the error message.
+
+
+<p>
+If the resulting function has upvalues,
+the first upvalue is set to the value of <code>env</code>,
+if that parameter is given,
+or to the value of the global environment.
+Other upvalues are initialized with <b>nil</b>.
+(When you load a main chunk,
+the resulting function will always have exactly one upvalue,
+the <code>_ENV</code> variable (see <a href="#2.2">&sect;2.2</a>).
+However,
+when you load a binary chunk created from a function (see <a href="#pdf-string.dump"><code>string.dump</code></a>),
+the resulting function can have an arbitrary number of upvalues.)
+All upvalues are fresh, that is,
+they are not shared with any other function.
+
+
+<p>
+<code>chunkname</code> is used as the name of the chunk for error messages
+and debug information (see <a href="#4.9">&sect;4.9</a>).
+When absent,
+it defaults to <code>chunk</code>, if <code>chunk</code> is a string,
+or to "<code>=(load)</code>" otherwise.
+
+
+<p>
+The string <code>mode</code> controls whether the chunk can be text or binary
+(that is, a precompiled chunk).
+It may be the string "<code>b</code>" (only binary chunks),
+"<code>t</code>" (only text chunks),
+or "<code>bt</code>" (both binary and text).
+The default is "<code>bt</code>".
+
+
+<p>
+Lua does not check the consistency of binary chunks.
+Maliciously crafted binary chunks can crash
+the interpreter.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-loadfile"><code>loadfile ([filename [, mode [, env]]])</code></a></h3>
+
+
+<p>
+Similar to <a href="#pdf-load"><code>load</code></a>,
+but gets the chunk from file <code>filename</code>
+or from the standard input,
+if no file name is given.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-next"><code>next (table [, index])</code></a></h3>
+
+
+<p>
+Allows a program to traverse all fields of a table.
+Its first argument is a table and its second argument
+is an index in this table.
+<code>next</code> returns the next index of the table
+and its associated value.
+When called with <b>nil</b> as its second argument,
+<code>next</code> returns an initial index
+and its associated value.
+When called with the last index,
+or with <b>nil</b> in an empty table,
+<code>next</code> returns <b>nil</b>.
+If the second argument is absent, then it is interpreted as <b>nil</b>.
+In particular,
+you can use <code>next(t)</code> to check whether a table is empty.
+
+
+<p>
+The order in which the indices are enumerated is not specified,
+<em>even for numeric indices</em>.
+(To traverse a table in numerical order,
+use a numerical <b>for</b>.)
+
+
+<p>
+The behavior of <code>next</code> is undefined if,
+during the traversal,
+you assign any value to a non-existent field in the table.
+You may however modify existing fields.
+In particular, you may clear existing fields.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-pairs"><code>pairs (t)</code></a></h3>
+
+
+<p>
+If <code>t</code> has a metamethod <code>__pairs</code>,
+calls it with <code>t</code> as argument and returns the first three
+results from the call.
+
+
+<p>
+Otherwise,
+returns three values: the <a href="#pdf-next"><code>next</code></a> function, the table <code>t</code>, and <b>nil</b>,
+so that the construction
+
+<pre>
+     for k,v in pairs(t) do <em>body</em> end
+</pre><p>
+will iterate over all key&ndash;value pairs of table <code>t</code>.
+
+
+<p>
+See function <a href="#pdf-next"><code>next</code></a> for the caveats of modifying
+the table during its traversal.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-pcall"><code>pcall (f [, arg1, &middot;&middot;&middot;])</code></a></h3>
+
+
+<p>
+Calls function <code>f</code> with
+the given arguments in <em>protected mode</em>.
+This means that any error inside&nbsp;<code>f</code> is not propagated;
+instead, <code>pcall</code> catches the error
+and returns a status code.
+Its first result is the status code (a boolean),
+which is true if the call succeeds without errors.
+In such case, <code>pcall</code> also returns all results from the call,
+after this first result.
+In case of any error, <code>pcall</code> returns <b>false</b> plus the error message.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-print"><code>print (&middot;&middot;&middot;)</code></a></h3>
+Receives any number of arguments
+and prints their values to <code>stdout</code>,
+using the <a href="#pdf-tostring"><code>tostring</code></a> function to convert each argument to a string.
+<code>print</code> is not intended for formatted output,
+but only as a quick way to show a value,
+for instance for debugging.
+For complete control over the output,
+use <a href="#pdf-string.format"><code>string.format</code></a> and <a href="#pdf-io.write"><code>io.write</code></a>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-rawequal"><code>rawequal (v1, v2)</code></a></h3>
+Checks whether <code>v1</code> is equal to <code>v2</code>,
+without invoking the <code>__eq</code> metamethod.
+Returns a boolean.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-rawget"><code>rawget (table, index)</code></a></h3>
+Gets the real value of <code>table[index]</code>,
+without invoking the <code>__index</code> metamethod.
+<code>table</code> must be a table;
+<code>index</code> may be any value.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-rawlen"><code>rawlen (v)</code></a></h3>
+Returns the length of the object <code>v</code>,
+which must be a table or a string,
+without invoking the <code>__len</code> metamethod.
+Returns an integer.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-rawset"><code>rawset (table, index, value)</code></a></h3>
+Sets the real value of <code>table[index]</code> to <code>value</code>,
+without invoking the <code>__newindex</code> metamethod.
+<code>table</code> must be a table,
+<code>index</code> any value different from <b>nil</b> and NaN,
+and <code>value</code> any Lua value.
+
+
+<p>
+This function returns <code>table</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-select"><code>select (index, &middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+If <code>index</code> is a number,
+returns all arguments after argument number <code>index</code>;
+a negative number indexes from the end (-1 is the last argument).
+Otherwise, <code>index</code> must be the string <code>"#"</code>,
+and <code>select</code> returns the total number of extra arguments it received.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-setmetatable"><code>setmetatable (table, metatable)</code></a></h3>
+
+
+<p>
+Sets the metatable for the given table.
+(To change the metatable of other types from Lua code,
+you must use the debug library (<a href="#6.10">&sect;6.10</a>).)
+If <code>metatable</code> is <b>nil</b>,
+removes the metatable of the given table.
+If the original metatable has a <code>__metatable</code> field,
+raises an error.
+
+
+<p>
+This function returns <code>table</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-tonumber"><code>tonumber (e [, base])</code></a></h3>
+
+
+<p>
+When called with no <code>base</code>,
+<code>tonumber</code> tries to convert its argument to a number.
+If the argument is already a number or
+a string convertible to a number,
+then <code>tonumber</code> returns this number;
+otherwise, it returns <b>nil</b>.
+
+
+<p>
+The conversion of strings can result in integers or floats,
+according to the lexical conventions of Lua (see <a href="#3.1">&sect;3.1</a>).
+(The string may have leading and trailing spaces and a sign.)
+
+
+<p>
+When called with <code>base</code>,
+then <code>e</code> must be a string to be interpreted as
+an integer numeral in that base.
+The base may be any integer between 2 and 36, inclusive.
+In bases above&nbsp;10, the letter '<code>A</code>' (in either upper or lower case)
+represents&nbsp;10, '<code>B</code>' represents&nbsp;11, and so forth,
+with '<code>Z</code>' representing 35.
+If the string <code>e</code> is not a valid numeral in the given base,
+the function returns <b>nil</b>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-tostring"><code>tostring (v)</code></a></h3>
+Receives a value of any type and
+converts it to a string in a human-readable format.
+(For complete control of how numbers are converted,
+use <a href="#pdf-string.format"><code>string.format</code></a>.)
+
+
+<p>
+If the metatable of <code>v</code> has a <code>__tostring</code> field,
+then <code>tostring</code> calls the corresponding value
+with <code>v</code> as argument,
+and uses the result of the call as its result.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-type"><code>type (v)</code></a></h3>
+Returns the type of its only argument, coded as a string.
+The possible results of this function are
+"<code>nil</code>" (a string, not the value <b>nil</b>),
+"<code>number</code>",
+"<code>string</code>",
+"<code>boolean</code>",
+"<code>table</code>",
+"<code>function</code>",
+"<code>thread</code>",
+and "<code>userdata</code>".
+
+
+
+
+<p>
+<hr><h3><a name="pdf-_VERSION"><code>_VERSION</code></a></h3>
+
+
+<p>
+A global variable (not a function) that
+holds a string containing the running Lua version.
+The current value of this variable is "<code>Lua 5.3</code>".
+
+
+
+
+<p>
+<hr><h3><a name="pdf-xpcall"><code>xpcall (f, msgh [, arg1, &middot;&middot;&middot;])</code></a></h3>
+
+
+<p>
+This function is similar to <a href="#pdf-pcall"><code>pcall</code></a>,
+except that it sets a new message handler <code>msgh</code>.
+
+
+
+
+
+
+
+<h2>6.2 &ndash; <a name="6.2">Coroutine Manipulation</a></h2>
+
+<p>
+This library comprises the operations to manipulate coroutines,
+which come inside the table <a name="pdf-coroutine"><code>coroutine</code></a>.
+See <a href="#2.6">&sect;2.6</a> for a general description of coroutines.
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.create"><code>coroutine.create (f)</code></a></h3>
+
+
+<p>
+Creates a new coroutine, with body <code>f</code>.
+<code>f</code> must be a function.
+Returns this new coroutine,
+an object with type <code>"thread"</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.isyieldable"><code>coroutine.isyieldable ()</code></a></h3>
+
+
+<p>
+Returns true when the running coroutine can yield.
+
+
+<p>
+A running coroutine is yieldable if it is not the main thread and
+it is not inside a non-yieldable C function.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.resume"><code>coroutine.resume (co [, val1, &middot;&middot;&middot;])</code></a></h3>
+
+
+<p>
+Starts or continues the execution of coroutine <code>co</code>.
+The first time you resume a coroutine,
+it starts running its body.
+The values <code>val1</code>, ... are passed
+as the arguments to the body function.
+If the coroutine has yielded,
+<code>resume</code> restarts it;
+the values <code>val1</code>, ... are passed
+as the results from the yield.
+
+
+<p>
+If the coroutine runs without any errors,
+<code>resume</code> returns <b>true</b> plus any values passed to <code>yield</code>
+(when the coroutine yields) or any values returned by the body function
+(when the coroutine terminates).
+If there is any error,
+<code>resume</code> returns <b>false</b> plus the error message.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.running"><code>coroutine.running ()</code></a></h3>
+
+
+<p>
+Returns the running coroutine plus a boolean,
+true when the running coroutine is the main one.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.status"><code>coroutine.status (co)</code></a></h3>
+
+
+<p>
+Returns the status of coroutine <code>co</code>, as a string:
+<code>"running"</code>,
+if the coroutine is running (that is, it called <code>status</code>);
+<code>"suspended"</code>, if the coroutine is suspended in a call to <code>yield</code>,
+or if it has not started running yet;
+<code>"normal"</code> if the coroutine is active but not running
+(that is, it has resumed another coroutine);
+and <code>"dead"</code> if the coroutine has finished its body function,
+or if it has stopped with an error.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.wrap"><code>coroutine.wrap (f)</code></a></h3>
+
+
+<p>
+Creates a new coroutine, with body <code>f</code>.
+<code>f</code> must be a function.
+Returns a function that resumes the coroutine each time it is called.
+Any arguments passed to the function behave as the
+extra arguments to <code>resume</code>.
+Returns the same values returned by <code>resume</code>,
+except the first boolean.
+In case of error, propagates the error.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-coroutine.yield"><code>coroutine.yield (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Suspends the execution of the calling coroutine.
+Any arguments to <code>yield</code> are passed as extra results to <code>resume</code>.
+
+
+
+
+
+
+
+<h2>6.3 &ndash; <a name="6.3">Modules</a></h2>
+
+<p>
+The package library provides basic
+facilities for loading modules in Lua.
+It exports one function directly in the global environment:
+<a href="#pdf-require"><code>require</code></a>.
+Everything else is exported in a table <a name="pdf-package"><code>package</code></a>.
+
+
+<p>
+<hr><h3><a name="pdf-require"><code>require (modname)</code></a></h3>
+
+
+<p>
+Loads the given module.
+The function starts by looking into the <a href="#pdf-package.loaded"><code>package.loaded</code></a> table
+to determine whether <code>modname</code> is already loaded.
+If it is, then <code>require</code> returns the value stored
+at <code>package.loaded[modname]</code>.
+Otherwise, it tries to find a <em>loader</em> for the module.
+
+
+<p>
+To find a loader,
+<code>require</code> is guided by the <a href="#pdf-package.searchers"><code>package.searchers</code></a> sequence.
+By changing this sequence,
+we can change how <code>require</code> looks for a module.
+The following explanation is based on the default configuration
+for <a href="#pdf-package.searchers"><code>package.searchers</code></a>.
+
+
+<p>
+First <code>require</code> queries <code>package.preload[modname]</code>.
+If it has a value,
+this value (which must be a function) is the loader.
+Otherwise <code>require</code> searches for a Lua loader using the
+path stored in <a href="#pdf-package.path"><code>package.path</code></a>.
+If that also fails, it searches for a C&nbsp;loader using the
+path stored in <a href="#pdf-package.cpath"><code>package.cpath</code></a>.
+If that also fails,
+it tries an <em>all-in-one</em> loader (see <a href="#pdf-package.searchers"><code>package.searchers</code></a>).
+
+
+<p>
+Once a loader is found,
+<code>require</code> calls the loader with two arguments:
+<code>modname</code> and an extra value dependent on how it got the loader.
+(If the loader came from a file,
+this extra value is the file name.)
+If the loader returns any non-nil value,
+<code>require</code> assigns the returned value to <code>package.loaded[modname]</code>.
+If the loader does not return a non-nil value and
+has not assigned any value to <code>package.loaded[modname]</code>,
+then <code>require</code> assigns <b>true</b> to this entry.
+In any case, <code>require</code> returns the
+final value of <code>package.loaded[modname]</code>.
+
+
+<p>
+If there is any error loading or running the module,
+or if it cannot find any loader for the module,
+then <code>require</code> raises an error.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.config"><code>package.config</code></a></h3>
+
+
+<p>
+A string describing some compile-time configurations for packages.
+This string is a sequence of lines:
+
+<ul>
+
+<li>The first line is the directory separator string.
+Default is '<code>\</code>' for Windows and '<code>/</code>' for all other systems.</li>
+
+<li>The second line is the character that separates templates in a path.
+Default is '<code>;</code>'.</li>
+
+<li>The third line is the string that marks the
+substitution points in a template.
+Default is '<code>?</code>'.</li>
+
+<li>The fourth line is a string that, in a path in Windows,
+is replaced by the executable's directory.
+Default is '<code>!</code>'.</li>
+
+<li>The fifth line is a mark to ignore all text after it
+when building the <code>luaopen_</code> function name.
+Default is '<code>-</code>'.</li>
+
+</ul>
+
+
+
+<p>
+<hr><h3><a name="pdf-package.cpath"><code>package.cpath</code></a></h3>
+
+
+<p>
+The path used by <a href="#pdf-require"><code>require</code></a> to search for a C&nbsp;loader.
+
+
+<p>
+Lua initializes the C&nbsp;path <a href="#pdf-package.cpath"><code>package.cpath</code></a> in the same way
+it initializes the Lua path <a href="#pdf-package.path"><code>package.path</code></a>,
+using the environment variable <a name="pdf-LUA_CPATH_5_3"><code>LUA_CPATH_5_3</code></a>
+or the environment variable <a name="pdf-LUA_CPATH"><code>LUA_CPATH</code></a>
+or a default path defined in <code>luaconf.h</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.loaded"><code>package.loaded</code></a></h3>
+
+
+<p>
+A table used by <a href="#pdf-require"><code>require</code></a> to control which
+modules are already loaded.
+When you require a module <code>modname</code> and
+<code>package.loaded[modname]</code> is not false,
+<a href="#pdf-require"><code>require</code></a> simply returns the value stored there.
+
+
+<p>
+This variable is only a reference to the real table;
+assignments to this variable do not change the
+table used by <a href="#pdf-require"><code>require</code></a>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.loadlib"><code>package.loadlib (libname, funcname)</code></a></h3>
+
+
+<p>
+Dynamically links the host program with the C&nbsp;library <code>libname</code>.
+
+
+<p>
+If <code>funcname</code> is "<code>*</code>",
+then it only links with the library,
+making the symbols exported by the library
+available to other dynamically linked libraries.
+Otherwise,
+it looks for a function <code>funcname</code> inside the library
+and returns this function as a C&nbsp;function.
+So, <code>funcname</code> must follow the <a href="#lua_CFunction"><code>lua_CFunction</code></a> prototype
+(see <a href="#lua_CFunction"><code>lua_CFunction</code></a>).
+
+
+<p>
+This is a low-level function.
+It completely bypasses the package and module system.
+Unlike <a href="#pdf-require"><code>require</code></a>,
+it does not perform any path searching and
+does not automatically adds extensions.
+<code>libname</code> must be the complete file name of the C&nbsp;library,
+including if necessary a path and an extension.
+<code>funcname</code> must be the exact name exported by the C&nbsp;library
+(which may depend on the C&nbsp;compiler and linker used).
+
+
+<p>
+This function is not supported by Standard&nbsp;C.
+As such, it is only available on some platforms
+(Windows, Linux, Mac OS X, Solaris, BSD,
+plus other Unix systems that support the <code>dlfcn</code> standard).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.path"><code>package.path</code></a></h3>
+
+
+<p>
+The path used by <a href="#pdf-require"><code>require</code></a> to search for a Lua loader.
+
+
+<p>
+At start-up, Lua initializes this variable with
+the value of the environment variable <a name="pdf-LUA_PATH_5_3"><code>LUA_PATH_5_3</code></a> or
+the environment variable <a name="pdf-LUA_PATH"><code>LUA_PATH</code></a> or
+with a default path defined in <code>luaconf.h</code>,
+if those environment variables are not defined.
+Any "<code>;;</code>" in the value of the environment variable
+is replaced by the default path.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.preload"><code>package.preload</code></a></h3>
+
+
+<p>
+A table to store loaders for specific modules
+(see <a href="#pdf-require"><code>require</code></a>).
+
+
+<p>
+This variable is only a reference to the real table;
+assignments to this variable do not change the
+table used by <a href="#pdf-require"><code>require</code></a>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.searchers"><code>package.searchers</code></a></h3>
+
+
+<p>
+A table used by <a href="#pdf-require"><code>require</code></a> to control how to load modules.
+
+
+<p>
+Each entry in this table is a <em>searcher function</em>.
+When looking for a module,
+<a href="#pdf-require"><code>require</code></a> calls each of these searchers in ascending order,
+with the module name (the argument given to <a href="#pdf-require"><code>require</code></a>) as its
+sole parameter.
+The function can return another function (the module <em>loader</em>)
+plus an extra value that will be passed to that loader,
+or a string explaining why it did not find that module
+(or <b>nil</b> if it has nothing to say).
+
+
+<p>
+Lua initializes this table with four searcher functions.
+
+
+<p>
+The first searcher simply looks for a loader in the
+<a href="#pdf-package.preload"><code>package.preload</code></a> table.
+
+
+<p>
+The second searcher looks for a loader as a Lua library,
+using the path stored at <a href="#pdf-package.path"><code>package.path</code></a>.
+The search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
+
+
+<p>
+The third searcher looks for a loader as a C&nbsp;library,
+using the path given by the variable <a href="#pdf-package.cpath"><code>package.cpath</code></a>.
+Again,
+the search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
+For instance,
+if the C&nbsp;path is the string
+
+<pre>
+     "./?.so;./?.dll;/usr/local/?/init.so"
+</pre><p>
+the searcher for module <code>foo</code>
+will try to open the files <code>./foo.so</code>, <code>./foo.dll</code>,
+and <code>/usr/local/foo/init.so</code>, in that order.
+Once it finds a C&nbsp;library,
+this searcher first uses a dynamic link facility to link the
+application with the library.
+Then it tries to find a C&nbsp;function inside the library to
+be used as the loader.
+The name of this C&nbsp;function is the string "<code>luaopen_</code>"
+concatenated with a copy of the module name where each dot
+is replaced by an underscore.
+Moreover, if the module name has a hyphen,
+its suffix after (and including) the first hyphen is removed.
+For instance, if the module name is <code>a.b.c-v2.1</code>,
+the function name will be <code>luaopen_a_b_c</code>.
+
+
+<p>
+The fourth searcher tries an <em>all-in-one loader</em>.
+It searches the C&nbsp;path for a library for
+the root name of the given module.
+For instance, when requiring <code>a.b.c</code>,
+it will search for a C&nbsp;library for <code>a</code>.
+If found, it looks into it for an open function for
+the submodule;
+in our example, that would be <code>luaopen_a_b_c</code>.
+With this facility, a package can pack several C&nbsp;submodules
+into one single library,
+with each submodule keeping its original open function.
+
+
+<p>
+All searchers except the first one (preload) return as the extra value
+the file name where the module was found,
+as returned by <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
+The first searcher returns no extra value.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-package.searchpath"><code>package.searchpath (name, path [, sep [, rep]])</code></a></h3>
+
+
+<p>
+Searches for the given <code>name</code> in the given <code>path</code>.
+
+
+<p>
+A path is a string containing a sequence of
+<em>templates</em> separated by semicolons.
+For each template,
+the function replaces each interrogation mark (if any)
+in the template with a copy of <code>name</code>
+wherein all occurrences of <code>sep</code>
+(a dot, by default)
+were replaced by <code>rep</code>
+(the system's directory separator, by default),
+and then tries to open the resulting file name.
+
+
+<p>
+For instance, if the path is the string
+
+<pre>
+     "./?.lua;./?.lc;/usr/local/?/init.lua"
+</pre><p>
+the search for the name <code>foo.a</code>
+will try to open the files
+<code>./foo/a.lua</code>, <code>./foo/a.lc</code>, and
+<code>/usr/local/foo/a/init.lua</code>, in that order.
+
+
+<p>
+Returns the resulting name of the first file that it can
+open in read mode (after closing the file),
+or <b>nil</b> plus an error message if none succeeds.
+(This error message lists all file names it tried to open.)
+
+
+
+
+
+
+
+<h2>6.4 &ndash; <a name="6.4">String Manipulation</a></h2>
+
+<p>
+This library provides generic functions for string manipulation,
+such as finding and extracting substrings, and pattern matching.
+When indexing a string in Lua, the first character is at position&nbsp;1
+(not at&nbsp;0, as in C).
+Indices are allowed to be negative and are interpreted as indexing backwards,
+from the end of the string.
+Thus, the last character is at position -1, and so on.
+
+
+<p>
+The string library provides all its functions inside the table
+<a name="pdf-string"><code>string</code></a>.
+It also sets a metatable for strings
+where the <code>__index</code> field points to the <code>string</code> table.
+Therefore, you can use the string functions in object-oriented style.
+For instance, <code>string.byte(s,i)</code>
+can be written as <code>s:byte(i)</code>.
+
+
+<p>
+The string library assumes one-byte character encodings.
+
+
+<p>
+<hr><h3><a name="pdf-string.byte"><code>string.byte (s [, i [, j]])</code></a></h3>
+Returns the internal numeric codes of the characters <code>s[i]</code>,
+<code>s[i+1]</code>, ..., <code>s[j]</code>.
+The default value for <code>i</code> is&nbsp;1;
+the default value for <code>j</code> is&nbsp;<code>i</code>.
+These indices are corrected
+following the same rules of function <a href="#pdf-string.sub"><code>string.sub</code></a>.
+
+
+<p>
+Numeric codes are not necessarily portable across platforms.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.char"><code>string.char (&middot;&middot;&middot;)</code></a></h3>
+Receives zero or more integers.
+Returns a string with length equal to the number of arguments,
+in which each character has the internal numeric code equal
+to its corresponding argument.
+
+
+<p>
+Numeric codes are not necessarily portable across platforms.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.dump"><code>string.dump (function [, strip])</code></a></h3>
+
+
+<p>
+Returns a string containing a binary representation
+(a <em>binary chunk</em>)
+of the given function,
+so that a later <a href="#pdf-load"><code>load</code></a> on this string returns
+a copy of the function (but with new upvalues).
+If <code>strip</code> is a true value,
+the binary representation may not include all debug information
+about the function,
+to save space.
+
+
+<p>
+Functions with upvalues have only their number of upvalues saved.
+When (re)loaded,
+those upvalues receive fresh instances containing <b>nil</b>.
+(You can use the debug library to serialize
+and reload the upvalues of a function
+in a way adequate to your needs.)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.find"><code>string.find (s, pattern [, init [, plain]])</code></a></h3>
+
+
+<p>
+Looks for the first match of
+<code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>) in the string <code>s</code>.
+If it finds a match, then <code>find</code> returns the indices of&nbsp;<code>s</code>
+where this occurrence starts and ends;
+otherwise, it returns <b>nil</b>.
+A third, optional numeric argument <code>init</code> specifies
+where to start the search;
+its default value is&nbsp;1 and can be negative.
+A value of <b>true</b> as a fourth, optional argument <code>plain</code>
+turns off the pattern matching facilities,
+so the function does a plain "find substring" operation,
+with no characters in <code>pattern</code> being considered magic.
+Note that if <code>plain</code> is given, then <code>init</code> must be given as well.
+
+
+<p>
+If the pattern has captures,
+then in a successful match
+the captured values are also returned,
+after the two indices.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.format"><code>string.format (formatstring, &middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Returns a formatted version of its variable number of arguments
+following the description given in its first argument (which must be a string).
+The format string follows the same rules as the ISO&nbsp;C function <code>sprintf</code>.
+The only differences are that the options/modifiers
+<code>*</code>, <code>h</code>, <code>L</code>, <code>l</code>, <code>n</code>,
+and <code>p</code> are not supported
+and that there is an extra option, <code>q</code>.
+
+
+<p>
+The <code>q</code> option formats a string between double quotes,
+using escape sequences when necessary to ensure that
+it can safely be read back by the Lua interpreter.
+For instance, the call
+
+<pre>
+     string.format('%q', 'a string with "quotes" and \n new line')
+</pre><p>
+may produce the string:
+
+<pre>
+     "a string with \"quotes\" and \
+      new line"
+</pre>
+
+<p>
+Options
+<code>A</code>, <code>a</code>, <code>E</code>, <code>e</code>, <code>f</code>,
+<code>G</code>, and <code>g</code> all expect a number as argument.
+Options <code>c</code>, <code>d</code>,
+<code>i</code>, <code>o</code>, <code>u</code>, <code>X</code>, and <code>x</code>
+expect an integer.
+When Lua is compiled with a C89 compiler,
+options <code>A</code> and <code>a</code> (hexadecimal floats)
+do not support any modifier (flags, width, length).
+
+
+<p>
+Option <code>s</code> expects a string;
+if its argument is not a string,
+it is converted to one following the same rules of <a href="#pdf-tostring"><code>tostring</code></a>.
+If the option has any modifier (flags, width, length),
+the string argument should not contain embedded zeros.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.gmatch"><code>string.gmatch (s, pattern)</code></a></h3>
+Returns an iterator function that,
+each time it is called,
+returns the next captures from <code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>)
+over the string <code>s</code>.
+If <code>pattern</code> specifies no captures,
+then the whole match is produced in each call.
+
+
+<p>
+As an example, the following loop
+will iterate over all the words from string <code>s</code>,
+printing one per line:
+
+<pre>
+     s = "hello world from Lua"
+     for w in string.gmatch(s, "%a+") do
+       print(w)
+     end
+</pre><p>
+The next example collects all pairs <code>key=value</code> from the
+given string into a table:
+
+<pre>
+     t = {}
+     s = "from=world, to=Lua"
+     for k, v in string.gmatch(s, "(%w+)=(%w+)") do
+       t[k] = v
+     end
+</pre>
+
+<p>
+For this function, a caret '<code>^</code>' at the start of a pattern does not
+work as an anchor, as this would prevent the iteration.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.gsub"><code>string.gsub (s, pattern, repl [, n])</code></a></h3>
+Returns a copy of <code>s</code>
+in which all (or the first <code>n</code>, if given)
+occurrences of the <code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>) have been
+replaced by a replacement string specified by <code>repl</code>,
+which can be a string, a table, or a function.
+<code>gsub</code> also returns, as its second value,
+the total number of matches that occurred.
+The name <code>gsub</code> comes from <em>Global SUBstitution</em>.
+
+
+<p>
+If <code>repl</code> is a string, then its value is used for replacement.
+The character&nbsp;<code>%</code> works as an escape character:
+any sequence in <code>repl</code> of the form <code>%<em>d</em></code>,
+with <em>d</em> between 1 and 9,
+stands for the value of the <em>d</em>-th captured substring.
+The sequence <code>%0</code> stands for the whole match.
+The sequence <code>%%</code> stands for a single&nbsp;<code>%</code>.
+
+
+<p>
+If <code>repl</code> is a table, then the table is queried for every match,
+using the first capture as the key.
+
+
+<p>
+If <code>repl</code> is a function, then this function is called every time a
+match occurs, with all captured substrings passed as arguments,
+in order.
+
+
+<p>
+In any case,
+if the pattern specifies no captures,
+then it behaves as if the whole pattern was inside a capture.
+
+
+<p>
+If the value returned by the table query or by the function call
+is a string or a number,
+then it is used as the replacement string;
+otherwise, if it is <b>false</b> or <b>nil</b>,
+then there is no replacement
+(that is, the original match is kept in the string).
+
+
+<p>
+Here are some examples:
+
+<pre>
+     x = string.gsub("hello world", "(%w+)", "%1 %1")
+     --&gt; x="hello hello world world"
+     
+     x = string.gsub("hello world", "%w+", "%0 %0", 1)
+     --&gt; x="hello hello world"
+     
+     x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
+     --&gt; x="world hello Lua from"
+     
+     x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
+     --&gt; x="home = /home/roberto, user = roberto"
+     
+     x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
+           return load(s)()
+         end)
+     --&gt; x="4+5 = 9"
+     
+     local t = {name="lua", version="5.3"}
+     x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t)
+     --&gt; x="lua-5.3.tar.gz"
+</pre>
+
+
+
+<p>
+<hr><h3><a name="pdf-string.len"><code>string.len (s)</code></a></h3>
+Receives a string and returns its length.
+The empty string <code>""</code> has length 0.
+Embedded zeros are counted,
+so <code>"a\000bc\000"</code> has length 5.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.lower"><code>string.lower (s)</code></a></h3>
+Receives a string and returns a copy of this string with all
+uppercase letters changed to lowercase.
+All other characters are left unchanged.
+The definition of what an uppercase letter is depends on the current locale.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.match"><code>string.match (s, pattern [, init])</code></a></h3>
+Looks for the first <em>match</em> of
+<code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>) in the string <code>s</code>.
+If it finds one, then <code>match</code> returns
+the captures from the pattern;
+otherwise it returns <b>nil</b>.
+If <code>pattern</code> specifies no captures,
+then the whole match is returned.
+A third, optional numeric argument <code>init</code> specifies
+where to start the search;
+its default value is&nbsp;1 and can be negative.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.pack"><code>string.pack (fmt, v1, v2, &middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Returns a binary string containing the values <code>v1</code>, <code>v2</code>, etc.
+packed (that is, serialized in binary form)
+according to the format string <code>fmt</code> (see <a href="#6.4.2">&sect;6.4.2</a>). 
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.packsize"><code>string.packsize (fmt)</code></a></h3>
+
+
+<p>
+Returns the size of a string resulting from <a href="#pdf-string.pack"><code>string.pack</code></a>
+with the given format.
+The format string cannot have the variable-length options
+'<code>s</code>' or '<code>z</code>' (see <a href="#6.4.2">&sect;6.4.2</a>).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.rep"><code>string.rep (s, n [, sep])</code></a></h3>
+Returns a string that is the concatenation of <code>n</code> copies of
+the string <code>s</code> separated by the string <code>sep</code>.
+The default value for <code>sep</code> is the empty string
+(that is, no separator).
+Returns the empty string if <code>n</code> is not positive.
+
+
+<p>
+(Note that it is very easy to exhaust the memory of your machine
+with a single call to this function.)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.reverse"><code>string.reverse (s)</code></a></h3>
+Returns a string that is the string <code>s</code> reversed.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.sub"><code>string.sub (s, i [, j])</code></a></h3>
+Returns the substring of <code>s</code> that
+starts at <code>i</code>  and continues until <code>j</code>;
+<code>i</code> and <code>j</code> can be negative.
+If <code>j</code> is absent, then it is assumed to be equal to -1
+(which is the same as the string length).
+In particular,
+the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code>
+with length <code>j</code>,
+and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code>
+with length <code>i</code>.
+
+
+<p>
+If, after the translation of negative indices,
+<code>i</code> is less than 1,
+it is corrected to 1.
+If <code>j</code> is greater than the string length,
+it is corrected to that length.
+If, after these corrections,
+<code>i</code> is greater than <code>j</code>,
+the function returns the empty string.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.unpack"><code>string.unpack (fmt, s [, pos])</code></a></h3>
+
+
+<p>
+Returns the values packed in string <code>s</code> (see <a href="#pdf-string.pack"><code>string.pack</code></a>)
+according to the format string <code>fmt</code> (see <a href="#6.4.2">&sect;6.4.2</a>).
+An optional <code>pos</code> marks where
+to start reading in <code>s</code> (default is 1).
+After the read values,
+this function also returns the index of the first unread byte in <code>s</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-string.upper"><code>string.upper (s)</code></a></h3>
+Receives a string and returns a copy of this string with all
+lowercase letters changed to uppercase.
+All other characters are left unchanged.
+The definition of what a lowercase letter is depends on the current locale.
+
+
+
+
+
+<h3>6.4.1 &ndash; <a name="6.4.1">Patterns</a></h3>
+
+<p>
+Patterns in Lua are described by regular strings,
+which are interpreted as patterns by the pattern-matching functions
+<a href="#pdf-string.find"><code>string.find</code></a>,
+<a href="#pdf-string.gmatch"><code>string.gmatch</code></a>,
+<a href="#pdf-string.gsub"><code>string.gsub</code></a>,
+and <a href="#pdf-string.match"><code>string.match</code></a>.
+This section describes the syntax and the meaning
+(that is, what they match) of these strings.
+
+
+
+<h4>Character Class:</h4><p>
+A <em>character class</em> is used to represent a set of characters.
+The following combinations are allowed in describing a character class:
+
+<ul>
+
+<li><b><em>x</em>: </b>
+(where <em>x</em> is not one of the <em>magic characters</em>
+<code>^$()%.[]*+-?</code>)
+represents the character <em>x</em> itself.
+</li>
+
+<li><b><code>.</code>: </b> (a dot) represents all characters.</li>
+
+<li><b><code>%a</code>: </b> represents all letters.</li>
+
+<li><b><code>%c</code>: </b> represents all control characters.</li>
+
+<li><b><code>%d</code>: </b> represents all digits.</li>
+
+<li><b><code>%g</code>: </b> represents all printable characters except space.</li>
+
+<li><b><code>%l</code>: </b> represents all lowercase letters.</li>
+
+<li><b><code>%p</code>: </b> represents all punctuation characters.</li>
+
+<li><b><code>%s</code>: </b> represents all space characters.</li>
+
+<li><b><code>%u</code>: </b> represents all uppercase letters.</li>
+
+<li><b><code>%w</code>: </b> represents all alphanumeric characters.</li>
+
+<li><b><code>%x</code>: </b> represents all hexadecimal digits.</li>
+
+<li><b><code>%<em>x</em></code>: </b> (where <em>x</em> is any non-alphanumeric character)
+represents the character <em>x</em>.
+This is the standard way to escape the magic characters.
+Any non-alphanumeric character
+(including all punctuation characters, even the non-magical)
+can be preceded by a '<code>%</code>'
+when used to represent itself in a pattern.
+</li>
+
+<li><b><code>[<em>set</em>]</code>: </b>
+represents the class which is the union of all
+characters in <em>set</em>.
+A range of characters can be specified by
+separating the end characters of the range,
+in ascending order, with a '<code>-</code>'.
+All classes <code>%</code><em>x</em> described above can also be used as
+components in <em>set</em>.
+All other characters in <em>set</em> represent themselves.
+For example, <code>[%w_]</code> (or <code>[_%w]</code>)
+represents all alphanumeric characters plus the underscore,
+<code>[0-7]</code> represents the octal digits,
+and <code>[0-7%l%-]</code> represents the octal digits plus
+the lowercase letters plus the '<code>-</code>' character.
+
+
+<p>
+You can put a closing square bracket in a set
+by positioning it as the first character in the set.
+You can put an hyphen in a set
+by positioning it as the first or the last character in the set.
+(You can also use an escape for both cases.)
+
+
+<p>
+The interaction between ranges and classes is not defined.
+Therefore, patterns like <code>[%a-z]</code> or <code>[a-%%]</code>
+have no meaning.
+</li>
+
+<li><b><code>[^<em>set</em>]</code>: </b>
+represents the complement of <em>set</em>,
+where <em>set</em> is interpreted as above.
+</li>
+
+</ul><p>
+For all classes represented by single letters (<code>%a</code>, <code>%c</code>, etc.),
+the corresponding uppercase letter represents the complement of the class.
+For instance, <code>%S</code> represents all non-space characters.
+
+
+<p>
+The definitions of letter, space, and other character groups
+depend on the current locale.
+In particular, the class <code>[a-z]</code> may not be equivalent to <code>%l</code>.
+
+
+
+
+
+<h4>Pattern Item:</h4><p>
+A <em>pattern item</em> can be
+
+<ul>
+
+<li>
+a single character class,
+which matches any single character in the class;
+</li>
+
+<li>
+a single character class followed by '<code>*</code>',
+which matches zero or more repetitions of characters in the class.
+These repetition items will always match the longest possible sequence;
+</li>
+
+<li>
+a single character class followed by '<code>+</code>',
+which matches one or more repetitions of characters in the class.
+These repetition items will always match the longest possible sequence;
+</li>
+
+<li>
+a single character class followed by '<code>-</code>',
+which also matches zero or more repetitions of characters in the class.
+Unlike '<code>*</code>',
+these repetition items will always match the shortest possible sequence;
+</li>
+
+<li>
+a single character class followed by '<code>?</code>',
+which matches zero or one occurrence of a character in the class.
+It always matches one occurrence if possible;
+</li>
+
+<li>
+<code>%<em>n</em></code>, for <em>n</em> between 1 and 9;
+such item matches a substring equal to the <em>n</em>-th captured string
+(see below);
+</li>
+
+<li>
+<code>%b<em>xy</em></code>, where <em>x</em> and <em>y</em> are two distinct characters;
+such item matches strings that start with&nbsp;<em>x</em>, end with&nbsp;<em>y</em>,
+and where the <em>x</em> and <em>y</em> are <em>balanced</em>.
+This means that, if one reads the string from left to right,
+counting <em>+1</em> for an <em>x</em> and <em>-1</em> for a <em>y</em>,
+the ending <em>y</em> is the first <em>y</em> where the count reaches 0.
+For instance, the item <code>%b()</code> matches expressions with
+balanced parentheses.
+</li>
+
+<li>
+<code>%f[<em>set</em>]</code>, a <em>frontier pattern</em>;
+such item matches an empty string at any position such that
+the next character belongs to <em>set</em>
+and the previous character does not belong to <em>set</em>.
+The set <em>set</em> is interpreted as previously described.
+The beginning and the end of the subject are handled as if
+they were the character '<code>\0</code>'.
+</li>
+
+</ul>
+
+
+
+
+<h4>Pattern:</h4><p>
+A <em>pattern</em> is a sequence of pattern items.
+A caret '<code>^</code>' at the beginning of a pattern anchors the match at the
+beginning of the subject string.
+A '<code>$</code>' at the end of a pattern anchors the match at the
+end of the subject string.
+At other positions,
+'<code>^</code>' and '<code>$</code>' have no special meaning and represent themselves.
+
+
+
+
+
+<h4>Captures:</h4><p>
+A pattern can contain sub-patterns enclosed in parentheses;
+they describe <em>captures</em>.
+When a match succeeds, the substrings of the subject string
+that match captures are stored (<em>captured</em>) for future use.
+Captures are numbered according to their left parentheses.
+For instance, in the pattern <code>"(a*(.)%w(%s*))"</code>,
+the part of the string matching <code>"a*(.)%w(%s*)"</code> is
+stored as the first capture (and therefore has number&nbsp;1);
+the character matching "<code>.</code>" is captured with number&nbsp;2,
+and the part matching "<code>%s*</code>" has number&nbsp;3.
+
+
+<p>
+As a special case, the empty capture <code>()</code> captures
+the current string position (a number).
+For instance, if we apply the pattern <code>"()aa()"</code> on the
+string <code>"flaaap"</code>, there will be two captures: 3&nbsp;and&nbsp;5.
+
+
+
+
+
+
+
+<h3>6.4.2 &ndash; <a name="6.4.2">Format Strings for Pack and Unpack</a></h3>
+
+<p>
+The first argument to <a href="#pdf-string.pack"><code>string.pack</code></a>,
+<a href="#pdf-string.packsize"><code>string.packsize</code></a>, and <a href="#pdf-string.unpack"><code>string.unpack</code></a>
+is a format string,
+which describes the layout of the structure being created or read.
+
+
+<p>
+A format string is a sequence of conversion options.
+The conversion options are as follows:
+
+<ul>
+<li><b><code>&lt;</code>: </b>sets little endian</li>
+<li><b><code>&gt;</code>: </b>sets big endian</li>
+<li><b><code>=</code>: </b>sets native endian</li>
+<li><b><code>![<em>n</em>]</code>: </b>sets maximum alignment to <code>n</code>
+(default is native alignment)</li>
+<li><b><code>b</code>: </b>a signed byte (<code>char</code>)</li>
+<li><b><code>B</code>: </b>an unsigned byte (<code>char</code>)</li>
+<li><b><code>h</code>: </b>a signed <code>short</code> (native size)</li>
+<li><b><code>H</code>: </b>an unsigned <code>short</code> (native size)</li>
+<li><b><code>l</code>: </b>a signed <code>long</code> (native size)</li>
+<li><b><code>L</code>: </b>an unsigned <code>long</code> (native size)</li>
+<li><b><code>j</code>: </b>a <code>lua_Integer</code></li>
+<li><b><code>J</code>: </b>a <code>lua_Unsigned</code></li>
+<li><b><code>T</code>: </b>a <code>size_t</code> (native size)</li>
+<li><b><code>i[<em>n</em>]</code>: </b>a signed <code>int</code> with <code>n</code> bytes
+(default is native size)</li>
+<li><b><code>I[<em>n</em>]</code>: </b>an unsigned <code>int</code> with <code>n</code> bytes
+(default is native size)</li>
+<li><b><code>f</code>: </b>a <code>float</code> (native size)</li>
+<li><b><code>d</code>: </b>a <code>double</code> (native size)</li>
+<li><b><code>n</code>: </b>a <code>lua_Number</code></li>
+<li><b><code>c<em>n</em></code>: </b>a fixed-sized string with <code>n</code> bytes</li>
+<li><b><code>z</code>: </b>a zero-terminated string</li>
+<li><b><code>s[<em>n</em>]</code>: </b>a string preceded by its length
+coded as an unsigned integer with <code>n</code> bytes
+(default is a <code>size_t</code>)</li>
+<li><b><code>x</code>: </b>one byte of padding</li>
+<li><b><code>X<em>op</em></code>: </b>an empty item that aligns
+according to option <code>op</code>
+(which is otherwise ignored)</li>
+<li><b>'<code> </code>': </b>(empty space) ignored</li>
+</ul><p>
+(A "<code>[<em>n</em>]</code>" means an optional integral numeral.)
+Except for padding, spaces, and configurations
+(options "<code>xX &lt;=&gt;!</code>"),
+each option corresponds to an argument (in <a href="#pdf-string.pack"><code>string.pack</code></a>)
+or a result (in <a href="#pdf-string.unpack"><code>string.unpack</code></a>).
+
+
+<p>
+For options "<code>!<em>n</em></code>", "<code>s<em>n</em></code>", "<code>i<em>n</em></code>", and "<code>I<em>n</em></code>",
+<code>n</code> can be any integer between 1 and 16.
+All integral options check overflows;
+<a href="#pdf-string.pack"><code>string.pack</code></a> checks whether the given value fits in the given size;
+<a href="#pdf-string.unpack"><code>string.unpack</code></a> checks whether the read value fits in a Lua integer.
+
+
+<p>
+Any format string starts as if prefixed by "<code>!1=</code>",
+that is,
+with maximum alignment of 1 (no alignment)
+and native endianness.
+
+
+<p>
+Alignment works as follows:
+For each option,
+the format gets extra padding until the data starts
+at an offset that is a multiple of the minimum between the
+option size and the maximum alignment;
+this minimum must be a power of 2.
+Options "<code>c</code>" and "<code>z</code>" are not aligned;
+option "<code>s</code>" follows the alignment of its starting integer.
+
+
+<p>
+All padding is filled with zeros by <a href="#pdf-string.pack"><code>string.pack</code></a>
+(and ignored by <a href="#pdf-string.unpack"><code>string.unpack</code></a>).
+
+
+
+
+
+
+
+<h2>6.5 &ndash; <a name="6.5">UTF-8 Support</a></h2>
+
+<p>
+This library provides basic support for UTF-8 encoding.
+It provides all its functions inside the table <a name="pdf-utf8"><code>utf8</code></a>.
+This library does not provide any support for Unicode other
+than the handling of the encoding.
+Any operation that needs the meaning of a character,
+such as character classification, is outside its scope.
+
+
+<p>
+Unless stated otherwise,
+all functions that expect a byte position as a parameter
+assume that the given position is either the start of a byte sequence
+or one plus the length of the subject string.
+As in the string library,
+negative indices count from the end of the string.
+
+
+<p>
+<hr><h3><a name="pdf-utf8.char"><code>utf8.char (&middot;&middot;&middot;)</code></a></h3>
+Receives zero or more integers,
+converts each one to its corresponding UTF-8 byte sequence
+and returns a string with the concatenation of all these sequences.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-utf8.charpattern"><code>utf8.charpattern</code></a></h3>
+The pattern (a string, not a function) "<code>[\0-\x7F\xC2-\xF4][\x80-\xBF]*</code>"
+(see <a href="#6.4.1">&sect;6.4.1</a>),
+which matches exactly one UTF-8 byte sequence,
+assuming that the subject is a valid UTF-8 string.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-utf8.codes"><code>utf8.codes (s)</code></a></h3>
+
+
+<p>
+Returns values so that the construction
+
+<pre>
+     for p, c in utf8.codes(s) do <em>body</em> end
+</pre><p>
+will iterate over all characters in string <code>s</code>,
+with <code>p</code> being the position (in bytes) and <code>c</code> the code point
+of each character.
+It raises an error if it meets any invalid byte sequence.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-utf8.codepoint"><code>utf8.codepoint (s [, i [, j]])</code></a></h3>
+Returns the codepoints (as integers) from all characters in <code>s</code>
+that start between byte position <code>i</code> and <code>j</code> (both included).
+The default for <code>i</code> is 1 and for <code>j</code> is <code>i</code>.
+It raises an error if it meets any invalid byte sequence.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-utf8.len"><code>utf8.len (s [, i [, j]])</code></a></h3>
+Returns the number of UTF-8 characters in string <code>s</code>
+that start between positions <code>i</code> and <code>j</code> (both inclusive).
+The default for <code>i</code> is 1 and for <code>j</code> is -1.
+If it finds any invalid byte sequence,
+returns a false value plus the position of the first invalid byte. 
+
+
+
+
+<p>
+<hr><h3><a name="pdf-utf8.offset"><code>utf8.offset (s, n [, i])</code></a></h3>
+Returns the position (in bytes) where the encoding of the
+<code>n</code>-th character of <code>s</code>
+(counting from position <code>i</code>) starts.
+A negative <code>n</code> gets characters before position <code>i</code>.
+The default for <code>i</code> is 1 when <code>n</code> is non-negative
+and <code>#s + 1</code> otherwise,
+so that <code>utf8.offset(s, -n)</code> gets the offset of the
+<code>n</code>-th character from the end of the string.
+If the specified character is neither in the subject
+nor right after its end,
+the function returns <b>nil</b>.
+
+
+<p>
+As a special case,
+when <code>n</code> is 0 the function returns the start of the encoding
+of the character that contains the <code>i</code>-th byte of <code>s</code>.
+
+
+<p>
+This function assumes that <code>s</code> is a valid UTF-8 string.
+
+
+
+
+
+
+
+<h2>6.6 &ndash; <a name="6.6">Table Manipulation</a></h2>
+
+<p>
+This library provides generic functions for table manipulation.
+It provides all its functions inside the table <a name="pdf-table"><code>table</code></a>.
+
+
+<p>
+Remember that, whenever an operation needs the length of a table,
+the table must be a proper sequence
+or have a <code>__len</code> metamethod (see <a href="#3.4.7">&sect;3.4.7</a>).
+All functions ignore non-numeric keys
+in the tables given as arguments.
+
+
+<p>
+<hr><h3><a name="pdf-table.concat"><code>table.concat (list [, sep [, i [, j]]])</code></a></h3>
+
+
+<p>
+Given a list where all elements are strings or numbers,
+returns the string <code>list[i]..sep..list[i+1] &middot;&middot;&middot; sep..list[j]</code>.
+The default value for <code>sep</code> is the empty string,
+the default for <code>i</code> is 1,
+and the default for <code>j</code> is <code>#list</code>.
+If <code>i</code> is greater than <code>j</code>, returns the empty string.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-table.insert"><code>table.insert (list, [pos,] value)</code></a></h3>
+
+
+<p>
+Inserts element <code>value</code> at position <code>pos</code> in <code>list</code>,
+shifting up the elements
+<code>list[pos], list[pos+1], &middot;&middot;&middot;, list[#list]</code>.
+The default value for <code>pos</code> is <code>#list+1</code>,
+so that a call <code>table.insert(t,x)</code> inserts <code>x</code> at the end
+of list <code>t</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-table.move"><code>table.move (a1, f, e, t [,a2])</code></a></h3>
+
+
+<p>
+Moves elements from table <code>a1</code> to table <code>a2</code>,
+performing the equivalent to the following
+multiple assignment:
+<code>a2[t],&middot;&middot;&middot; = a1[f],&middot;&middot;&middot;,a1[e]</code>.
+The default for <code>a2</code> is <code>a1</code>.
+The destination range can overlap with the source range.
+The number of elements to be moved must fit in a Lua integer.
+
+
+<p>
+Returns the destination table <code>a2</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-table.pack"><code>table.pack (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Returns a new table with all parameters stored into keys 1, 2, etc.
+and with a field "<code>n</code>" with the total number of parameters.
+Note that the resulting table may not be a sequence.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-table.remove"><code>table.remove (list [, pos])</code></a></h3>
+
+
+<p>
+Removes from <code>list</code> the element at position <code>pos</code>,
+returning the value of the removed element.
+When <code>pos</code> is an integer between 1 and <code>#list</code>,
+it shifts down the elements
+<code>list[pos+1], list[pos+2], &middot;&middot;&middot;, list[#list]</code>
+and erases element <code>list[#list]</code>;
+The index <code>pos</code> can also be 0 when <code>#list</code> is 0,
+or <code>#list + 1</code>;
+in those cases, the function erases the element <code>list[pos]</code>.
+
+
+<p>
+The default value for <code>pos</code> is <code>#list</code>,
+so that a call <code>table.remove(l)</code> removes the last element
+of list <code>l</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-table.sort"><code>table.sort (list [, comp])</code></a></h3>
+
+
+<p>
+Sorts list elements in a given order, <em>in-place</em>,
+from <code>list[1]</code> to <code>list[#list]</code>.
+If <code>comp</code> is given,
+then it must be a function that receives two list elements
+and returns true when the first element must come
+before the second in the final order
+(so that, after the sort,
+<code>i &lt; j</code> implies <code>not comp(list[j],list[i])</code>).
+If <code>comp</code> is not given,
+then the standard Lua operator <code>&lt;</code> is used instead.
+
+
+<p>
+Note that the <code>comp</code> function must define
+a strict partial order over the elements in the list;
+that is, it must be asymmetric and transitive.
+Otherwise, no valid sort may be possible.
+
+
+<p>
+The sort algorithm is not stable;
+that is, elements not comparable by the given order
+(e.g., equal elements)
+may have their relative positions changed by the sort.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-table.unpack"><code>table.unpack (list [, i [, j]])</code></a></h3>
+
+
+<p>
+Returns the elements from the given list.
+This function is equivalent to
+
+<pre>
+     return list[i], list[i+1], &middot;&middot;&middot;, list[j]
+</pre><p>
+By default, <code>i</code> is&nbsp;1 and <code>j</code> is <code>#list</code>.
+
+
+
+
+
+
+
+<h2>6.7 &ndash; <a name="6.7">Mathematical Functions</a></h2>
+
+<p>
+This library provides basic mathematical functions.
+It provides all its functions and constants inside the table <a name="pdf-math"><code>math</code></a>.
+Functions with the annotation "<code>integer/float</code>" give
+integer results for integer arguments
+and float results for float (or mixed) arguments.
+Rounding functions
+(<a href="#pdf-math.ceil"><code>math.ceil</code></a>, <a href="#pdf-math.floor"><code>math.floor</code></a>, and <a href="#pdf-math.modf"><code>math.modf</code></a>)
+return an integer when the result fits in the range of an integer,
+or a float otherwise.
+
+
+<p>
+<hr><h3><a name="pdf-math.abs"><code>math.abs (x)</code></a></h3>
+
+
+<p>
+Returns the absolute value of <code>x</code>. (integer/float)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.acos"><code>math.acos (x)</code></a></h3>
+
+
+<p>
+Returns the arc cosine of <code>x</code> (in radians).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.asin"><code>math.asin (x)</code></a></h3>
+
+
+<p>
+Returns the arc sine of <code>x</code> (in radians).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.atan"><code>math.atan (y [, x])</code></a></h3>
+
+
+<p>
+
+Returns the arc tangent of <code>y/x</code> (in radians),
+but uses the signs of both parameters to find the
+quadrant of the result.
+(It also handles correctly the case of <code>x</code> being zero.)
+
+
+<p>
+The default value for <code>x</code> is 1,
+so that the call <code>math.atan(y)</code>
+returns the arc tangent of <code>y</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.ceil"><code>math.ceil (x)</code></a></h3>
+
+
+<p>
+Returns the smallest integral value larger than or equal to <code>x</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.cos"><code>math.cos (x)</code></a></h3>
+
+
+<p>
+Returns the cosine of <code>x</code> (assumed to be in radians).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.deg"><code>math.deg (x)</code></a></h3>
+
+
+<p>
+Converts the angle <code>x</code> from radians to degrees.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.exp"><code>math.exp (x)</code></a></h3>
+
+
+<p>
+Returns the value <em>e<sup>x</sup></em>
+(where <code>e</code> is the base of natural logarithms).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.floor"><code>math.floor (x)</code></a></h3>
+
+
+<p>
+Returns the largest integral value smaller than or equal to <code>x</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.fmod"><code>math.fmod (x, y)</code></a></h3>
+
+
+<p>
+Returns the remainder of the division of <code>x</code> by <code>y</code>
+that rounds the quotient towards zero. (integer/float)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.huge"><code>math.huge</code></a></h3>
+
+
+<p>
+The float value <code>HUGE_VAL</code>,
+a value larger than any other numeric value.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.log"><code>math.log (x [, base])</code></a></h3>
+
+
+<p>
+Returns the logarithm of <code>x</code> in the given base.
+The default for <code>base</code> is <em>e</em>
+(so that the function returns the natural logarithm of <code>x</code>).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.max"><code>math.max (x, &middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Returns the argument with the maximum value,
+according to the Lua operator <code>&lt;</code>. (integer/float)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.maxinteger"><code>math.maxinteger</code></a></h3>
+An integer with the maximum value for an integer.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.min"><code>math.min (x, &middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Returns the argument with the minimum value,
+according to the Lua operator <code>&lt;</code>. (integer/float)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.mininteger"><code>math.mininteger</code></a></h3>
+An integer with the minimum value for an integer.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.modf"><code>math.modf (x)</code></a></h3>
+
+
+<p>
+Returns the integral part of <code>x</code> and the fractional part of <code>x</code>.
+Its second result is always a float.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.pi"><code>math.pi</code></a></h3>
+
+
+<p>
+The value of <em>&pi;</em>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.rad"><code>math.rad (x)</code></a></h3>
+
+
+<p>
+Converts the angle <code>x</code> from degrees to radians.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.random"><code>math.random ([m [, n]])</code></a></h3>
+
+
+<p>
+When called without arguments,
+returns a pseudo-random float with uniform distribution
+in the range  <em>[0,1)</em>.  
+When called with two integers <code>m</code> and <code>n</code>,
+<code>math.random</code> returns a pseudo-random integer
+with uniform distribution in the range <em>[m, n]</em>.
+(The value <em>n-m</em> cannot be negative and must fit in a Lua integer.)
+The call <code>math.random(n)</code> is equivalent to <code>math.random(1,n)</code>.
+
+
+<p>
+This function is an interface to the underling
+pseudo-random generator function provided by C.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.randomseed"><code>math.randomseed (x)</code></a></h3>
+
+
+<p>
+Sets <code>x</code> as the "seed"
+for the pseudo-random generator:
+equal seeds produce equal sequences of numbers.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.sin"><code>math.sin (x)</code></a></h3>
+
+
+<p>
+Returns the sine of <code>x</code> (assumed to be in radians).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.sqrt"><code>math.sqrt (x)</code></a></h3>
+
+
+<p>
+Returns the square root of <code>x</code>.
+(You can also use the expression <code>x^0.5</code> to compute this value.)
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.tan"><code>math.tan (x)</code></a></h3>
+
+
+<p>
+Returns the tangent of <code>x</code> (assumed to be in radians).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.tointeger"><code>math.tointeger (x)</code></a></h3>
+
+
+<p>
+If the value <code>x</code> is convertible to an integer,
+returns that integer.
+Otherwise, returns <b>nil</b>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.type"><code>math.type (x)</code></a></h3>
+
+
+<p>
+Returns "<code>integer</code>" if <code>x</code> is an integer,
+"<code>float</code>" if it is a float,
+or <b>nil</b> if <code>x</code> is not a number.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-math.ult"><code>math.ult (m, n)</code></a></h3>
+
+
+<p>
+Returns a boolean,
+true if integer <code>m</code> is below integer <code>n</code> when
+they are compared as unsigned integers.
+
+
+
+
+
+
+
+<h2>6.8 &ndash; <a name="6.8">Input and Output Facilities</a></h2>
+
+<p>
+The I/O library provides two different styles for file manipulation.
+The first one uses implicit file handles;
+that is, there are operations to set a default input file and a
+default output file,
+and all input/output operations are over these default files.
+The second style uses explicit file handles.
+
+
+<p>
+When using implicit file handles,
+all operations are supplied by table <a name="pdf-io"><code>io</code></a>.
+When using explicit file handles,
+the operation <a href="#pdf-io.open"><code>io.open</code></a> returns a file handle
+and then all operations are supplied as methods of the file handle.
+
+
+<p>
+The table <code>io</code> also provides
+three predefined file handles with their usual meanings from C:
+<a name="pdf-io.stdin"><code>io.stdin</code></a>, <a name="pdf-io.stdout"><code>io.stdout</code></a>, and <a name="pdf-io.stderr"><code>io.stderr</code></a>.
+The I/O library never closes these files.
+
+
+<p>
+Unless otherwise stated,
+all I/O functions return <b>nil</b> on failure
+(plus an error message as a second result and
+a system-dependent error code as a third result)
+and some value different from <b>nil</b> on success.
+On non-POSIX systems,
+the computation of the error message and error code
+in case of errors
+may be not thread safe,
+because they rely on the global C variable <code>errno</code>.
+
+
+<p>
+<hr><h3><a name="pdf-io.close"><code>io.close ([file])</code></a></h3>
+
+
+<p>
+Equivalent to <code>file:close()</code>.
+Without a <code>file</code>, closes the default output file.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.flush"><code>io.flush ()</code></a></h3>
+
+
+<p>
+Equivalent to <code>io.output():flush()</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.input"><code>io.input ([file])</code></a></h3>
+
+
+<p>
+When called with a file name, it opens the named file (in text mode),
+and sets its handle as the default input file.
+When called with a file handle,
+it simply sets this file handle as the default input file.
+When called without parameters,
+it returns the current default input file.
+
+
+<p>
+In case of errors this function raises the error,
+instead of returning an error code.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.lines"><code>io.lines ([filename, &middot;&middot;&middot;])</code></a></h3>
+
+
+<p>
+Opens the given file name in read mode
+and returns an iterator function that
+works like <code>file:lines(&middot;&middot;&middot;)</code> over the opened file.
+When the iterator function detects the end of file,
+it returns no values (to finish the loop) and automatically closes the file.
+
+
+<p>
+The call <code>io.lines()</code> (with no file name) is equivalent
+to <code>io.input():lines("*l")</code>;
+that is, it iterates over the lines of the default input file.
+In this case it does not close the file when the loop ends.
+
+
+<p>
+In case of errors this function raises the error,
+instead of returning an error code.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.open"><code>io.open (filename [, mode])</code></a></h3>
+
+
+<p>
+This function opens a file,
+in the mode specified in the string <code>mode</code>.
+In case of success,
+it returns a new file handle.
+
+
+<p>
+The <code>mode</code> string can be any of the following:
+
+<ul>
+<li><b>"<code>r</code>": </b> read mode (the default);</li>
+<li><b>"<code>w</code>": </b> write mode;</li>
+<li><b>"<code>a</code>": </b> append mode;</li>
+<li><b>"<code>r+</code>": </b> update mode, all previous data is preserved;</li>
+<li><b>"<code>w+</code>": </b> update mode, all previous data is erased;</li>
+<li><b>"<code>a+</code>": </b> append update mode, previous data is preserved,
+  writing is only allowed at the end of file.</li>
+</ul><p>
+The <code>mode</code> string can also have a '<code>b</code>' at the end,
+which is needed in some systems to open the file in binary mode.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.output"><code>io.output ([file])</code></a></h3>
+
+
+<p>
+Similar to <a href="#pdf-io.input"><code>io.input</code></a>, but operates over the default output file.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.popen"><code>io.popen (prog [, mode])</code></a></h3>
+
+
+<p>
+This function is system dependent and is not available
+on all platforms.
+
+
+<p>
+Starts program <code>prog</code> in a separated process and returns
+a file handle that you can use to read data from this program
+(if <code>mode</code> is <code>"r"</code>, the default)
+or to write data to this program
+(if <code>mode</code> is <code>"w"</code>).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.read"><code>io.read (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Equivalent to <code>io.input():read(&middot;&middot;&middot;)</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.tmpfile"><code>io.tmpfile ()</code></a></h3>
+
+
+<p>
+In case of success,
+returns a handle for a temporary file.
+This file is opened in update mode
+and it is automatically removed when the program ends.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.type"><code>io.type (obj)</code></a></h3>
+
+
+<p>
+Checks whether <code>obj</code> is a valid file handle.
+Returns the string <code>"file"</code> if <code>obj</code> is an open file handle,
+<code>"closed file"</code> if <code>obj</code> is a closed file handle,
+or <b>nil</b> if <code>obj</code> is not a file handle.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-io.write"><code>io.write (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Equivalent to <code>io.output():write(&middot;&middot;&middot;)</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:close"><code>file:close ()</code></a></h3>
+
+
+<p>
+Closes <code>file</code>.
+Note that files are automatically closed when
+their handles are garbage collected,
+but that takes an unpredictable amount of time to happen.
+
+
+<p>
+When closing a file handle created with <a href="#pdf-io.popen"><code>io.popen</code></a>,
+<a href="#pdf-file:close"><code>file:close</code></a> returns the same values
+returned by <a href="#pdf-os.execute"><code>os.execute</code></a>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:flush"><code>file:flush ()</code></a></h3>
+
+
+<p>
+Saves any written data to <code>file</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:lines"><code>file:lines (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Returns an iterator function that,
+each time it is called,
+reads the file according to the given formats.
+When no format is given,
+uses "<code>l</code>" as a default.
+As an example, the construction
+
+<pre>
+     for c in file:lines(1) do <em>body</em> end
+</pre><p>
+will iterate over all characters of the file,
+starting at the current position.
+Unlike <a href="#pdf-io.lines"><code>io.lines</code></a>, this function does not close the file
+when the loop ends.
+
+
+<p>
+In case of errors this function raises the error,
+instead of returning an error code.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:read"><code>file:read (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Reads the file <code>file</code>,
+according to the given formats, which specify what to read.
+For each format,
+the function returns a string or a number with the characters read,
+or <b>nil</b> if it cannot read data with the specified format.
+(In this latter case,
+the function does not read subsequent formats.)
+When called without formats,
+it uses a default format that reads the next line
+(see below).
+
+
+<p>
+The available formats are
+
+<ul>
+
+<li><b>"<code>n</code>": </b>
+reads a numeral and returns it as a float or an integer,
+following the lexical conventions of Lua.
+(The numeral may have leading spaces and a sign.)
+This format always reads the longest input sequence that
+is a valid prefix for a numeral;
+if that prefix does not form a valid numeral
+(e.g., an empty string, "<code>0x</code>", or "<code>3.4e-</code>"),
+it is discarded and the function returns <b>nil</b>.
+</li>
+
+<li><b>"<code>a</code>": </b>
+reads the whole file, starting at the current position.
+On end of file, it returns the empty string.
+</li>
+
+<li><b>"<code>l</code>": </b>
+reads the next line skipping the end of line,
+returning <b>nil</b> on end of file.
+This is the default format.
+</li>
+
+<li><b>"<code>L</code>": </b>
+reads the next line keeping the end-of-line character (if present),
+returning <b>nil</b> on end of file.
+</li>
+
+<li><b><em>number</em>: </b>
+reads a string with up to this number of bytes,
+returning <b>nil</b> on end of file.
+If <code>number</code> is zero,
+it reads nothing and returns an empty string,
+or <b>nil</b> on end of file.
+</li>
+
+</ul><p>
+The formats "<code>l</code>" and "<code>L</code>" should be used only for text files.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:seek"><code>file:seek ([whence [, offset]])</code></a></h3>
+
+
+<p>
+Sets and gets the file position,
+measured from the beginning of the file,
+to the position given by <code>offset</code> plus a base
+specified by the string <code>whence</code>, as follows:
+
+<ul>
+<li><b>"<code>set</code>": </b> base is position 0 (beginning of the file);</li>
+<li><b>"<code>cur</code>": </b> base is current position;</li>
+<li><b>"<code>end</code>": </b> base is end of file;</li>
+</ul><p>
+In case of success, <code>seek</code> returns the final file position,
+measured in bytes from the beginning of the file.
+If <code>seek</code> fails, it returns <b>nil</b>,
+plus a string describing the error.
+
+
+<p>
+The default value for <code>whence</code> is <code>"cur"</code>,
+and for <code>offset</code> is 0.
+Therefore, the call <code>file:seek()</code> returns the current
+file position, without changing it;
+the call <code>file:seek("set")</code> sets the position to the
+beginning of the file (and returns 0);
+and the call <code>file:seek("end")</code> sets the position to the
+end of the file, and returns its size.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:setvbuf"><code>file:setvbuf (mode [, size])</code></a></h3>
+
+
+<p>
+Sets the buffering mode for an output file.
+There are three available modes:
+
+<ul>
+
+<li><b>"<code>no</code>": </b>
+no buffering; the result of any output operation appears immediately.
+</li>
+
+<li><b>"<code>full</code>": </b>
+full buffering; output operation is performed only
+when the buffer is full or when
+you explicitly <code>flush</code> the file (see <a href="#pdf-io.flush"><code>io.flush</code></a>).
+</li>
+
+<li><b>"<code>line</code>": </b>
+line buffering; output is buffered until a newline is output
+or there is any input from some special files
+(such as a terminal device).
+</li>
+
+</ul><p>
+For the last two cases, <code>size</code>
+specifies the size of the buffer, in bytes.
+The default is an appropriate size.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-file:write"><code>file:write (&middot;&middot;&middot;)</code></a></h3>
+
+
+<p>
+Writes the value of each of its arguments to <code>file</code>.
+The arguments must be strings or numbers.
+
+
+<p>
+In case of success, this function returns <code>file</code>.
+Otherwise it returns <b>nil</b> plus a string describing the error.
+
+
+
+
+
+
+
+<h2>6.9 &ndash; <a name="6.9">Operating System Facilities</a></h2>
+
+<p>
+This library is implemented through table <a name="pdf-os"><code>os</code></a>.
+
+
+<p>
+<hr><h3><a name="pdf-os.clock"><code>os.clock ()</code></a></h3>
+
+
+<p>
+Returns an approximation of the amount in seconds of CPU time
+used by the program.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.date"><code>os.date ([format [, time]])</code></a></h3>
+
+
+<p>
+Returns a string or a table containing date and time,
+formatted according to the given string <code>format</code>.
+
+
+<p>
+If the <code>time</code> argument is present,
+this is the time to be formatted
+(see the <a href="#pdf-os.time"><code>os.time</code></a> function for a description of this value).
+Otherwise, <code>date</code> formats the current time.
+
+
+<p>
+If <code>format</code> starts with '<code>!</code>',
+then the date is formatted in Coordinated Universal Time.
+After this optional character,
+if <code>format</code> is the string "<code>*t</code>",
+then <code>date</code> returns a table with the following fields:
+<code>year</code>, <code>month</code> (1&ndash;12), <code>day</code> (1&ndash;31),
+<code>hour</code> (0&ndash;23), <code>min</code> (0&ndash;59), <code>sec</code> (0&ndash;61),
+<code>wday</code> (weekday, 1&ndash;7, Sunday is&nbsp;1),
+<code>yday</code> (day of the year, 1&ndash;366),
+and <code>isdst</code> (daylight saving flag, a boolean).
+This last field may be absent
+if the information is not available.
+
+
+<p>
+If <code>format</code> is not "<code>*t</code>",
+then <code>date</code> returns the date as a string,
+formatted according to the same rules as the ISO&nbsp;C function <code>strftime</code>.
+
+
+<p>
+When called without arguments,
+<code>date</code> returns a reasonable date and time representation that depends on
+the host system and on the current locale.
+(More specifically, <code>os.date()</code> is equivalent to <code>os.date("%c")</code>.)
+
+
+<p>
+On non-POSIX systems,
+this function may be not thread safe
+because of its reliance on C&nbsp;function <code>gmtime</code> and C&nbsp;function <code>localtime</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.difftime"><code>os.difftime (t2, t1)</code></a></h3>
+
+
+<p>
+Returns the difference, in seconds,
+from time <code>t1</code> to time <code>t2</code>
+(where the times are values returned by <a href="#pdf-os.time"><code>os.time</code></a>).
+In POSIX, Windows, and some other systems,
+this value is exactly <code>t2</code><em>-</em><code>t1</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.execute"><code>os.execute ([command])</code></a></h3>
+
+
+<p>
+This function is equivalent to the ISO&nbsp;C function <code>system</code>.
+It passes <code>command</code> to be executed by an operating system shell.
+Its first result is <b>true</b>
+if the command terminated successfully,
+or <b>nil</b> otherwise.
+After this first result
+the function returns a string plus a number,
+as follows:
+
+<ul>
+
+<li><b>"<code>exit</code>": </b>
+the command terminated normally;
+the following number is the exit status of the command.
+</li>
+
+<li><b>"<code>signal</code>": </b>
+the command was terminated by a signal;
+the following number is the signal that terminated the command.
+</li>
+
+</ul>
+
+<p>
+When called without a <code>command</code>,
+<code>os.execute</code> returns a boolean that is true if a shell is available.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.exit"><code>os.exit ([code [, close]])</code></a></h3>
+
+
+<p>
+Calls the ISO&nbsp;C function <code>exit</code> to terminate the host program.
+If <code>code</code> is <b>true</b>,
+the returned status is <code>EXIT_SUCCESS</code>;
+if <code>code</code> is <b>false</b>,
+the returned status is <code>EXIT_FAILURE</code>;
+if <code>code</code> is a number,
+the returned status is this number.
+The default value for <code>code</code> is <b>true</b>.
+
+
+<p>
+If the optional second argument <code>close</code> is true,
+closes the Lua state before exiting.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.getenv"><code>os.getenv (varname)</code></a></h3>
+
+
+<p>
+Returns the value of the process environment variable <code>varname</code>,
+or <b>nil</b> if the variable is not defined.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.remove"><code>os.remove (filename)</code></a></h3>
+
+
+<p>
+Deletes the file (or empty directory, on POSIX systems)
+with the given name.
+If this function fails, it returns <b>nil</b>,
+plus a string describing the error and the error code.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.rename"><code>os.rename (oldname, newname)</code></a></h3>
+
+
+<p>
+Renames file or directory named <code>oldname</code> to <code>newname</code>.
+If this function fails, it returns <b>nil</b>,
+plus a string describing the error and the error code.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.setlocale"><code>os.setlocale (locale [, category])</code></a></h3>
+
+
+<p>
+Sets the current locale of the program.
+<code>locale</code> is a system-dependent string specifying a locale;
+<code>category</code> is an optional string describing which category to change:
+<code>"all"</code>, <code>"collate"</code>, <code>"ctype"</code>,
+<code>"monetary"</code>, <code>"numeric"</code>, or <code>"time"</code>;
+the default category is <code>"all"</code>.
+The function returns the name of the new locale,
+or <b>nil</b> if the request cannot be honored.
+
+
+<p>
+If <code>locale</code> is the empty string,
+the current locale is set to an implementation-defined native locale.
+If <code>locale</code> is the string "<code>C</code>",
+the current locale is set to the standard C locale.
+
+
+<p>
+When called with <b>nil</b> as the first argument,
+this function only returns the name of the current locale
+for the given category.
+
+
+<p>
+This function may be not thread safe
+because of its reliance on C&nbsp;function <code>setlocale</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.time"><code>os.time ([table])</code></a></h3>
+
+
+<p>
+Returns the current time when called without arguments,
+or a time representing the local date and time specified by the given table.
+This table must have fields <code>year</code>, <code>month</code>, and <code>day</code>,
+and may have fields
+<code>hour</code> (default is 12),
+<code>min</code> (default is 0),
+<code>sec</code> (default is 0),
+and <code>isdst</code> (default is <b>nil</b>).
+Other fields are ignored.
+For a description of these fields, see the <a href="#pdf-os.date"><code>os.date</code></a> function.
+
+
+<p>
+The values in these fields do not need to be inside their valid ranges.
+For instance, if <code>sec</code> is -10,
+it means -10 seconds from the time specified by the other fields;
+if <code>hour</code> is 1000,
+it means +1000 hours from the time specified by the other fields.
+
+
+<p>
+The returned value is a number, whose meaning depends on your system.
+In POSIX, Windows, and some other systems,
+this number counts the number
+of seconds since some given start time (the "epoch").
+In other systems, the meaning is not specified,
+and the number returned by <code>time</code> can be used only as an argument to
+<a href="#pdf-os.date"><code>os.date</code></a> and <a href="#pdf-os.difftime"><code>os.difftime</code></a>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-os.tmpname"><code>os.tmpname ()</code></a></h3>
+
+
+<p>
+Returns a string with a file name that can
+be used for a temporary file.
+The file must be explicitly opened before its use
+and explicitly removed when no longer needed.
+
+
+<p>
+On POSIX systems,
+this function also creates a file with that name,
+to avoid security risks.
+(Someone else might create the file with wrong permissions
+in the time between getting the name and creating the file.)
+You still have to open the file to use it
+and to remove it (even if you do not use it).
+
+
+<p>
+When possible,
+you may prefer to use <a href="#pdf-io.tmpfile"><code>io.tmpfile</code></a>,
+which automatically removes the file when the program ends.
+
+
+
+
+
+
+
+<h2>6.10 &ndash; <a name="6.10">The Debug Library</a></h2>
+
+<p>
+This library provides
+the functionality of the debug interface (<a href="#4.9">&sect;4.9</a>) to Lua programs.
+You should exert care when using this library.
+Several of its functions
+violate basic assumptions about Lua code
+(e.g., that variables local to a function
+cannot be accessed from outside;
+that userdata metatables cannot be changed by Lua code;
+that Lua programs do not crash)
+and therefore can compromise otherwise secure code.
+Moreover, some functions in this library may be slow.
+
+
+<p>
+All functions in this library are provided
+inside the <a name="pdf-debug"><code>debug</code></a> table.
+All functions that operate over a thread
+have an optional first argument which is the
+thread to operate over.
+The default is always the current thread.
+
+
+<p>
+<hr><h3><a name="pdf-debug.debug"><code>debug.debug ()</code></a></h3>
+
+
+<p>
+Enters an interactive mode with the user,
+running each string that the user enters.
+Using simple commands and other debug facilities,
+the user can inspect global and local variables,
+change their values, evaluate expressions, and so on.
+A line containing only the word <code>cont</code> finishes this function,
+so that the caller continues its execution.
+
+
+<p>
+Note that commands for <code>debug.debug</code> are not lexically nested
+within any function and so have no direct access to local variables.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.gethook"><code>debug.gethook ([thread])</code></a></h3>
+
+
+<p>
+Returns the current hook settings of the thread, as three values:
+the current hook function, the current hook mask,
+and the current hook count
+(as set by the <a href="#pdf-debug.sethook"><code>debug.sethook</code></a> function).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.getinfo"><code>debug.getinfo ([thread,] f [, what])</code></a></h3>
+
+
+<p>
+Returns a table with information about a function.
+You can give the function directly
+or you can give a number as the value of <code>f</code>,
+which means the function running at level <code>f</code> of the call stack
+of the given thread:
+level&nbsp;0 is the current function (<code>getinfo</code> itself);
+level&nbsp;1 is the function that called <code>getinfo</code>
+(except for tail calls, which do not count on the stack);
+and so on.
+If <code>f</code> is a number larger than the number of active functions,
+then <code>getinfo</code> returns <b>nil</b>.
+
+
+<p>
+The returned table can contain all the fields returned by <a href="#lua_getinfo"><code>lua_getinfo</code></a>,
+with the string <code>what</code> describing which fields to fill in.
+The default for <code>what</code> is to get all information available,
+except the table of valid lines.
+If present,
+the option '<code>f</code>'
+adds a field named <code>func</code> with the function itself.
+If present,
+the option '<code>L</code>'
+adds a field named <code>activelines</code> with the table of
+valid lines.
+
+
+<p>
+For instance, the expression <code>debug.getinfo(1,"n").name</code> returns
+a name for the current function,
+if a reasonable name can be found,
+and the expression <code>debug.getinfo(print)</code>
+returns a table with all available information
+about the <a href="#pdf-print"><code>print</code></a> function.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.getlocal"><code>debug.getlocal ([thread,] f, local)</code></a></h3>
+
+
+<p>
+This function returns the name and the value of the local variable
+with index <code>local</code> of the function at level <code>f</code> of the stack.
+This function accesses not only explicit local variables,
+but also parameters, temporaries, etc.
+
+
+<p>
+The first parameter or local variable has index&nbsp;1, and so on,
+following the order that they are declared in the code,
+counting only the variables that are active
+in the current scope of the function.
+Negative indices refer to vararg parameters;
+-1 is the first vararg parameter.
+The function returns <b>nil</b> if there is no variable with the given index,
+and raises an error when called with a level out of range.
+(You can call <a href="#pdf-debug.getinfo"><code>debug.getinfo</code></a> to check whether the level is valid.)
+
+
+<p>
+Variable names starting with '<code>(</code>' (open parenthesis) 
+represent variables with no known names
+(internal variables such as loop control variables,
+and variables from chunks saved without debug information).
+
+
+<p>
+The parameter <code>f</code> may also be a function.
+In that case, <code>getlocal</code> returns only the name of function parameters.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.getmetatable"><code>debug.getmetatable (value)</code></a></h3>
+
+
+<p>
+Returns the metatable of the given <code>value</code>
+or <b>nil</b> if it does not have a metatable.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.getregistry"><code>debug.getregistry ()</code></a></h3>
+
+
+<p>
+Returns the registry table (see <a href="#4.5">&sect;4.5</a>).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.getupvalue"><code>debug.getupvalue (f, up)</code></a></h3>
+
+
+<p>
+This function returns the name and the value of the upvalue
+with index <code>up</code> of the function <code>f</code>.
+The function returns <b>nil</b> if there is no upvalue with the given index.
+
+
+<p>
+Variable names starting with '<code>(</code>' (open parenthesis) 
+represent variables with no known names
+(variables from chunks saved without debug information).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.getuservalue"><code>debug.getuservalue (u)</code></a></h3>
+
+
+<p>
+Returns the Lua value associated to <code>u</code>.
+If <code>u</code> is not a userdata,
+returns <b>nil</b>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.sethook"><code>debug.sethook ([thread,] hook, mask [, count])</code></a></h3>
+
+
+<p>
+Sets the given function as a hook.
+The string <code>mask</code> and the number <code>count</code> describe
+when the hook will be called.
+The string mask may have any combination of the following characters,
+with the given meaning:
+
+<ul>
+<li><b>'<code>c</code>': </b> the hook is called every time Lua calls a function;</li>
+<li><b>'<code>r</code>': </b> the hook is called every time Lua returns from a function;</li>
+<li><b>'<code>l</code>': </b> the hook is called every time Lua enters a new line of code.</li>
+</ul><p>
+Moreover,
+with a <code>count</code> different from zero,
+the hook is called also after every <code>count</code> instructions.
+
+
+<p>
+When called without arguments,
+<a href="#pdf-debug.sethook"><code>debug.sethook</code></a> turns off the hook.
+
+
+<p>
+When the hook is called, its first parameter is a string
+describing the event that has triggered its call:
+<code>"call"</code> (or <code>"tail call"</code>),
+<code>"return"</code>,
+<code>"line"</code>, and <code>"count"</code>.
+For line events,
+the hook also gets the new line number as its second parameter.
+Inside a hook,
+you can call <code>getinfo</code> with level&nbsp;2 to get more information about
+the running function
+(level&nbsp;0 is the <code>getinfo</code> function,
+and level&nbsp;1 is the hook function).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.setlocal"><code>debug.setlocal ([thread,] level, local, value)</code></a></h3>
+
+
+<p>
+This function assigns the value <code>value</code> to the local variable
+with index <code>local</code> of the function at level <code>level</code> of the stack.
+The function returns <b>nil</b> if there is no local
+variable with the given index,
+and raises an error when called with a <code>level</code> out of range.
+(You can call <code>getinfo</code> to check whether the level is valid.)
+Otherwise, it returns the name of the local variable.
+
+
+<p>
+See <a href="#pdf-debug.getlocal"><code>debug.getlocal</code></a> for more information about
+variable indices and names.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.setmetatable"><code>debug.setmetatable (value, table)</code></a></h3>
+
+
+<p>
+Sets the metatable for the given <code>value</code> to the given <code>table</code>
+(which can be <b>nil</b>).
+Returns <code>value</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.setupvalue"><code>debug.setupvalue (f, up, value)</code></a></h3>
+
+
+<p>
+This function assigns the value <code>value</code> to the upvalue
+with index <code>up</code> of the function <code>f</code>.
+The function returns <b>nil</b> if there is no upvalue
+with the given index.
+Otherwise, it returns the name of the upvalue.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.setuservalue"><code>debug.setuservalue (udata, value)</code></a></h3>
+
+
+<p>
+Sets the given <code>value</code> as
+the Lua value associated to the given <code>udata</code>.
+<code>udata</code> must be a full userdata.
+
+
+<p>
+Returns <code>udata</code>.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.traceback"><code>debug.traceback ([thread,] [message [, level]])</code></a></h3>
+
+
+<p>
+If <code>message</code> is present but is neither a string nor <b>nil</b>,
+this function returns <code>message</code> without further processing.
+Otherwise,
+it returns a string with a traceback of the call stack.
+The optional <code>message</code> string is appended
+at the beginning of the traceback.
+An optional <code>level</code> number tells at which level
+to start the traceback
+(default is 1, the function calling <code>traceback</code>).
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.upvalueid"><code>debug.upvalueid (f, n)</code></a></h3>
+
+
+<p>
+Returns a unique identifier (as a light userdata)
+for the upvalue numbered <code>n</code>
+from the given function.
+
+
+<p>
+These unique identifiers allow a program to check whether different
+closures share upvalues.
+Lua closures that share an upvalue
+(that is, that access a same external local variable)
+will return identical ids for those upvalue indices.
+
+
+
+
+<p>
+<hr><h3><a name="pdf-debug.upvaluejoin"><code>debug.upvaluejoin (f1, n1, f2, n2)</code></a></h3>
+
+
+<p>
+Make the <code>n1</code>-th upvalue of the Lua closure <code>f1</code>
+refer to the <code>n2</code>-th upvalue of the Lua closure <code>f2</code>.
+
+
+
+
+
+
+
+<h1>7 &ndash; <a name="7">Lua Standalone</a></h1>
+
+<p>
+Although Lua has been designed as an extension language,
+to be embedded in a host C&nbsp;program,
+it is also frequently used as a standalone language.
+An interpreter for Lua as a standalone language,
+called simply <code>lua</code>,
+is provided with the standard distribution.
+The standalone interpreter includes
+all standard libraries, including the debug library.
+Its usage is:
+
+<pre>
+     lua [options] [script [args]]
+</pre><p>
+The options are:
+
+<ul>
+<li><b><code>-e <em>stat</em></code>: </b> executes string <em>stat</em>;</li>
+<li><b><code>-l <em>mod</em></code>: </b> "requires" <em>mod</em>;</li>
+<li><b><code>-i</code>: </b> enters interactive mode after running <em>script</em>;</li>
+<li><b><code>-v</code>: </b> prints version information;</li>
+<li><b><code>-E</code>: </b> ignores environment variables;</li>
+<li><b><code>--</code>: </b> stops handling options;</li>
+<li><b><code>-</code>: </b> executes <code>stdin</code> as a file and stops handling options.</li>
+</ul><p>
+After handling its options, <code>lua</code> runs the given <em>script</em>.
+When called without arguments,
+<code>lua</code> behaves as <code>lua -v -i</code>
+when the standard input (<code>stdin</code>) is a terminal,
+and as <code>lua -</code> otherwise.
+
+
+<p>
+When called without option <code>-E</code>, 
+the interpreter checks for an environment variable <a name="pdf-LUA_INIT_5_3"><code>LUA_INIT_5_3</code></a>
+(or <a name="pdf-LUA_INIT"><code>LUA_INIT</code></a> if the versioned name is not defined)
+before running any argument.
+If the variable content has the format <code>@<em>filename</em></code>,
+then <code>lua</code> executes the file.
+Otherwise, <code>lua</code> executes the string itself.
+
+
+<p>
+When called with option <code>-E</code>,
+besides ignoring <code>LUA_INIT</code>,
+Lua also ignores
+the values of <code>LUA_PATH</code> and <code>LUA_CPATH</code>,
+setting the values of
+<a href="#pdf-package.path"><code>package.path</code></a> and <a href="#pdf-package.cpath"><code>package.cpath</code></a>
+with the default paths defined in <code>luaconf.h</code>.
+
+
+<p>
+All options are handled in order, except <code>-i</code> and <code>-E</code>.
+For instance, an invocation like
+
+<pre>
+     $ lua -e'a=1' -e 'print(a)' script.lua
+</pre><p>
+will first set <code>a</code> to 1, then print the value of <code>a</code>,
+and finally run the file <code>script.lua</code> with no arguments.
+(Here <code>$</code> is the shell prompt. Your prompt may be different.)
+
+
+<p>
+Before running any code,
+<code>lua</code> collects all command-line arguments
+in a global table called <code>arg</code>.
+The script name goes to index 0,
+the first argument after the script name goes to index 1,
+and so on.
+Any arguments before the script name
+(that is, the interpreter name plus its options)
+go to negative indices.
+For instance, in the call
+
+<pre>
+     $ lua -la b.lua t1 t2
+</pre><p>
+the table is like this:
+
+<pre>
+     arg = { [-2] = "lua", [-1] = "-la",
+             [0] = "b.lua",
+             [1] = "t1", [2] = "t2" }
+</pre><p>
+If there is no script in the call,
+the interpreter name goes to index 0,
+followed by the other arguments.
+For instance, the call
+
+<pre>
+     $ lua -e "print(arg[1])"
+</pre><p>
+will print "<code>-e</code>".
+If there is a script,
+the script is called with parameters
+<code>arg[1]</code>, &middot;&middot;&middot;, <code>arg[#arg]</code>.
+(Like all chunks in Lua,
+the script is compiled as a vararg function.)
+
+
+<p>
+In interactive mode,
+Lua repeatedly prompts and waits for a line.
+After reading a line,
+Lua first try to interpret the line as an expression.
+If it succeeds, it prints its value.
+Otherwise, it interprets the line as a statement.
+If you write an incomplete statement,
+the interpreter waits for its completion
+by issuing a different prompt.
+
+
+<p>
+If the global variable <a name="pdf-_PROMPT"><code>_PROMPT</code></a> contains a string,
+then its value is used as the prompt.
+Similarly, if the global variable <a name="pdf-_PROMPT2"><code>_PROMPT2</code></a> contains a string,
+its value is used as the secondary prompt
+(issued during incomplete statements).
+
+
+<p>
+In case of unprotected errors in the script,
+the interpreter reports the error to the standard error stream.
+If the error object is not a string but 
+has a metamethod <code>__tostring</code>,
+the interpreter calls this metamethod to produce the final message.
+Otherwise, the interpreter converts the error object to a string
+and adds a stack traceback to it.
+
+
+<p>
+When finishing normally,
+the interpreter closes its main Lua state
+(see <a href="#lua_close"><code>lua_close</code></a>).
+The script can avoid this step by
+calling <a href="#pdf-os.exit"><code>os.exit</code></a> to terminate.
+
+
+<p>
+To allow the use of Lua as a
+script interpreter in Unix systems,
+the standalone interpreter skips
+the first line of a chunk if it starts with <code>#</code>.
+Therefore, Lua scripts can be made into executable programs
+by using <code>chmod +x</code> and the&nbsp;<code>#!</code> form,
+as in
+
+<pre>
+     #!/usr/local/bin/lua
+</pre><p>
+(Of course,
+the location of the Lua interpreter may be different in your machine.
+If <code>lua</code> is in your <code>PATH</code>,
+then
+
+<pre>
+     #!/usr/bin/env lua
+</pre><p>
+is a more portable solution.)
+
+
+
+<h1>8 &ndash; <a name="8">Incompatibilities with the Previous Version</a></h1>
+
+<p>
+Here we list the incompatibilities that you may find when moving a program
+from Lua&nbsp;5.2 to Lua&nbsp;5.3.
+You can avoid some incompatibilities by compiling Lua with
+appropriate options (see file <code>luaconf.h</code>).
+However,
+all these compatibility options will be removed in the future.
+
+
+<p>
+Lua versions can always change the C API in ways that
+do not imply source-code changes in a program,
+such as the numeric values for constants
+or the implementation of functions as macros.
+Therefore,
+you should not assume that binaries are compatible between
+different Lua versions.
+Always recompile clients of the Lua API when
+using a new version.
+
+
+<p>
+Similarly, Lua versions can always change the internal representation
+of precompiled chunks;
+precompiled chunks are not compatible between different Lua versions.
+
+
+<p>
+The standard paths in the official distribution may
+change between versions.
+
+
+
+<h2>8.1 &ndash; <a name="8.1">Changes in the Language</a></h2>
+<ul>
+
+<li>
+The main difference between Lua&nbsp;5.2 and Lua&nbsp;5.3 is the
+introduction of an integer subtype for numbers.
+Although this change should not affect "normal" computations,
+some computations
+(mainly those that involve some kind of overflow)
+can give different results.
+
+
+<p>
+You can fix these differences by forcing a number to be a float
+(in Lua&nbsp;5.2 all numbers were float),
+in particular writing constants with an ending <code>.0</code>
+or using <code>x = x + 0.0</code> to convert a variable.
+(This recommendation is only for a quick fix
+for an occasional incompatibility;
+it is not a general guideline for good programming.
+For good programming,
+use floats where you need floats
+and integers where you need integers.)
+</li>
+
+<li>
+The conversion of a float to a string now adds a <code>.0</code> suffix
+to the result if it looks like an integer.
+(For instance, the float 2.0 will be printed as <code>2.0</code>,
+not as <code>2</code>.)
+You should always use an explicit format
+when you need a specific format for numbers.
+
+
+<p>
+(Formally this is not an incompatibility,
+because Lua does not specify how numbers are formatted as strings,
+but some programs assumed a specific format.)
+</li>
+
+<li>
+The generational mode for the garbage collector was removed.
+(It was an experimental feature in Lua&nbsp;5.2.)
+</li>
+
+</ul>
+
+
+
+
+<h2>8.2 &ndash; <a name="8.2">Changes in the Libraries</a></h2>
+<ul>
+
+<li>
+The <code>bit32</code> library has been deprecated.
+It is easy to require a compatible external library or,
+better yet, to replace its functions with appropriate bitwise operations.
+(Keep in mind that <code>bit32</code> operates on 32-bit integers,
+while the bitwise operators in Lua&nbsp;5.3 operate on Lua integers,
+which by default have 64&nbsp;bits.)
+</li>
+
+<li>
+The Table library now respects metamethods
+for setting and getting elements.
+</li>
+
+<li>
+The <a href="#pdf-ipairs"><code>ipairs</code></a> iterator now respects metamethods and
+its <code>__ipairs</code> metamethod has been deprecated.
+</li>
+
+<li>
+Option names in <a href="#pdf-io.read"><code>io.read</code></a> do not have a starting '<code>*</code>' anymore.
+For compatibility, Lua will continue to accept (and ignore) this character.
+</li>
+
+<li>
+The following functions were deprecated in the mathematical library:
+<code>atan2</code>, <code>cosh</code>, <code>sinh</code>, <code>tanh</code>, <code>pow</code>,
+<code>frexp</code>, and <code>ldexp</code>.
+You can replace <code>math.pow(x,y)</code> with <code>x^y</code>;
+you can replace <code>math.atan2</code> with <code>math.atan</code>,
+which now accepts one or two parameters;
+you can replace <code>math.ldexp(x,exp)</code> with <code>x * 2.0^exp</code>.
+For the other operations,
+you can either use an external library or
+implement them in Lua.
+</li>
+
+<li>
+The searcher for C loaders used by <a href="#pdf-require"><code>require</code></a>
+changed the way it handles versioned names.
+Now, the version should come after the module name
+(as is usual in most other tools).
+For compatibility, that searcher still tries the old format
+if it cannot find an open function according to the new style.
+(Lua&nbsp;5.2 already worked that way,
+but it did not document the change.)
+</li>
+
+<li>
+The call <code>collectgarbage("count")</code> now returns only one result.
+(You can compute that second result from the fractional part
+of the first result.)
+</li>
+
+</ul>
+
+
+
+
+<h2>8.3 &ndash; <a name="8.3">Changes in the API</a></h2>
+
+
+<ul>
+
+<li>
+Continuation functions now receive as parameters what they needed
+to get through <code>lua_getctx</code>,
+so <code>lua_getctx</code> has been removed.
+Adapt your code accordingly.
+</li>
+
+<li>
+Function <a href="#lua_dump"><code>lua_dump</code></a> has an extra parameter, <code>strip</code>.
+Use 0 as the value of this parameter to get the old behavior.
+</li>
+
+<li>
+Functions to inject/project unsigned integers
+(<code>lua_pushunsigned</code>, <code>lua_tounsigned</code>, <code>lua_tounsignedx</code>,
+<code>luaL_checkunsigned</code>, <code>luaL_optunsigned</code>)
+were deprecated.
+Use their signed equivalents with a type cast.
+</li>
+
+<li>
+Macros to project non-default integer types
+(<code>luaL_checkint</code>, <code>luaL_optint</code>, <code>luaL_checklong</code>, <code>luaL_optlong</code>)
+were deprecated.
+Use their equivalent over <a href="#lua_Integer"><code>lua_Integer</code></a> with a type cast
+(or, when possible, use <a href="#lua_Integer"><code>lua_Integer</code></a> in your code).
+</li>
+
+</ul>
+
+
+
+
+<h1>9 &ndash; <a name="9">The Complete Syntax of Lua</a></h1>
+
+<p>
+Here is the complete syntax of Lua in extended BNF.
+As usual in extended BNF,
+{A} means 0 or more As,
+and [A] means an optional A.
+(For operator precedences, see <a href="#3.4.8">&sect;3.4.8</a>;
+for a description of the terminals
+Name, Numeral,
+and LiteralString, see <a href="#3.1">&sect;3.1</a>.)
+
+
+
+
+<pre>
+
+	chunk ::= block
+
+	block ::= {stat} [retstat]
+
+	stat ::=  &lsquo;<b>;</b>&rsquo; | 
+		 varlist &lsquo;<b>=</b>&rsquo; explist | 
+		 functioncall | 
+		 label | 
+		 <b>break</b> | 
+		 <b>goto</b> Name | 
+		 <b>do</b> block <b>end</b> | 
+		 <b>while</b> exp <b>do</b> block <b>end</b> | 
+		 <b>repeat</b> block <b>until</b> exp | 
+		 <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> | 
+		 <b>for</b> Name &lsquo;<b>=</b>&rsquo; exp &lsquo;<b>,</b>&rsquo; exp [&lsquo;<b>,</b>&rsquo; exp] <b>do</b> block <b>end</b> | 
+		 <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> | 
+		 <b>function</b> funcname funcbody | 
+		 <b>local</b> <b>function</b> Name funcbody | 
+		 <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist] 
+
+	retstat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
+
+	label ::= &lsquo;<b>::</b>&rsquo; Name &lsquo;<b>::</b>&rsquo;
+
+	funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
+
+	varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
+
+	var ::=  Name | prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; | prefixexp &lsquo;<b>.</b>&rsquo; Name 
+
+	namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
+
+	explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
+
+	exp ::=  <b>nil</b> | <b>false</b> | <b>true</b> | Numeral | LiteralString | &lsquo;<b>...</b>&rsquo; | functiondef | 
+		 prefixexp | tableconstructor | exp binop exp | unop exp 
+
+	prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
+
+	functioncall ::=  prefixexp args | prefixexp &lsquo;<b>:</b>&rsquo; Name args 
+
+	args ::=  &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo; | tableconstructor | LiteralString 
+
+	functiondef ::= <b>function</b> funcbody
+
+	funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
+
+	parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
+
+	tableconstructor ::= &lsquo;<b>{</b>&rsquo; [fieldlist] &lsquo;<b>}</b>&rsquo;
+
+	fieldlist ::= field {fieldsep field} [fieldsep]
+
+	field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
+
+	fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
+
+	binop ::=  &lsquo;<b>+</b>&rsquo; | &lsquo;<b>-</b>&rsquo; | &lsquo;<b>*</b>&rsquo; | &lsquo;<b>/</b>&rsquo; | &lsquo;<b>//</b>&rsquo; | &lsquo;<b>^</b>&rsquo; | &lsquo;<b>%</b>&rsquo; | 
+		 &lsquo;<b>&amp;</b>&rsquo; | &lsquo;<b>~</b>&rsquo; | &lsquo;<b>|</b>&rsquo; | &lsquo;<b>&gt;&gt;</b>&rsquo; | &lsquo;<b>&lt;&lt;</b>&rsquo; | &lsquo;<b>..</b>&rsquo; | 
+		 &lsquo;<b>&lt;</b>&rsquo; | &lsquo;<b>&lt;=</b>&rsquo; | &lsquo;<b>&gt;</b>&rsquo; | &lsquo;<b>&gt;=</b>&rsquo; | &lsquo;<b>==</b>&rsquo; | &lsquo;<b>~=</b>&rsquo; | 
+		 <b>and</b> | <b>or</b>
+
+	unop ::= &lsquo;<b>-</b>&rsquo; | <b>not</b> | &lsquo;<b>#</b>&rsquo; | &lsquo;<b>~</b>&rsquo;
+
+</pre>
+
+<p>
+
+
+
+
+
+
+
+
+<P CLASS="footer">
+Last update:
+Mon May 30 13:11:08 BRT 2016
+</P>
+<!--
+Last change: revised for Lua 5.3.3
+-->
+
+</body></html>
+
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@@ -0,0 +1,365 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<HTML>
+<HEAD>
+<TITLE>Lua 5.3 readme</TITLE>
+<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css">
+<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1">
+<STYLE TYPE="text/css">
+blockquote, .display {
+	border: solid #a0a0a0 2px ;
+	border-radius: 8px ;
+	padding: 1em ;
+	margin: 0px ;
+}
+
+.display {
+	word-spacing: 0.25em ;
+}
+
+dl.display dd {
+	padding-bottom: 0.2em ;
+}
+
+tt, kbd, code {
+	font-size: 12pt ;
+}
+</STYLE>
+</HEAD>
+
+<BODY>
+
+<H1>
+<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua"></A>
+Welcome to Lua 5.3
+</H1>
+
+<DIV CLASS="menubar">
+<A HREF="#about">about</A>
+&middot;
+<A HREF="#install">installation</A>
+&middot;
+<A HREF="#changes">changes</A>
+&middot;
+<A HREF="#license">license</A>
+&middot;
+<A HREF="contents.html">reference manual</A>
+</DIV>
+
+<H2><A NAME="about">About Lua</A></H2>
+<P>
+Lua is a powerful, fast, lightweight, embeddable scripting language
+developed by a
+<A HREF="http://www.lua.org/authors.html">team</A>
+at
+<A HREF="http://www.puc-rio.br/">PUC-Rio</A>,
+the Pontifical Catholic University of Rio de Janeiro in Brazil.
+Lua is
+<A HREF="#license">free software</A>
+used in many products and projects around the world.
+
+<P>
+Lua's
+<A HREF="http://www.lua.org/">official web site</A>
+provides complete information
+about Lua,
+including
+an
+<A HREF="http://www.lua.org/about.html">executive summary</A>
+and
+updated
+<A HREF="http://www.lua.org/docs.html">documentation</A>,
+especially the
+<A HREF="http://www.lua.org/manual/5.3/">reference manual</A>,
+which may differ slightly from the
+<A HREF="contents.html">local copy</A>
+distributed in this package.
+
+<H2><A NAME="install">Installing Lua</A></H2>
+<P>
+Lua is distributed in
+<A HREF="http://www.lua.org/ftp/">source</A>
+form.
+You need to build it before using it.
+Building Lua should be straightforward
+because
+Lua is implemented in pure ANSI C and compiles unmodified in all known
+platforms that have an ANSI C compiler.
+Lua also compiles unmodified as C++.
+The instructions given below for building Lua are for Unix-like platforms.
+See also
+<A HREF="#other">instructions for other systems</A>
+and
+<A HREF="#customization">customization options</A>.
+
+<P>
+If you don't have the time or the inclination to compile Lua yourself,
+get a binary from
+<A HREF="http://lua-users.org/wiki/LuaBinaries">LuaBinaries</A>.
+Try also
+<A HREF="http://luadist.org/">LuaDist</A>,
+a multi-platform distribution of Lua that includes batteries.
+
+<H3>Building Lua</H3>
+<P>
+In most Unix-like platforms, simply do "<KBD>make</KBD>" with a suitable target.
+Here are the details.
+
+<OL>
+<LI>
+Open a terminal window and move to
+the top-level directory, which is named <TT>lua-5.3.x</TT>.
+The <TT>Makefile</TT> there controls both the build process and the installation process.
+<P>
+<LI>
+  Do "<KBD>make</KBD>" and see if your platform is listed.
+  The platforms currently supported are:
+<P>
+<P CLASS="display">
+   aix bsd c89 freebsd generic linux macosx mingw posix solaris
+</P>
+<P>
+  If your platform is listed, just do "<KBD>make xxx</KBD>", where xxx
+  is your platform name.
+<P>
+  If your platform is not listed, try the closest one or posix, generic,
+  c89, in this order.
+<P>
+<LI>
+The compilation takes only a few moments
+and produces three files in the <TT>src</TT> directory:
+lua (the interpreter),
+luac (the compiler),
+and liblua.a (the library).
+<P>
+<LI>
+  To check that Lua has been built correctly, do "<KBD>make test</KBD>"
+  after building Lua. This will run the interpreter and print its version.
+</OL>
+<P>
+If you're running Linux and get compilation errors,
+make sure you have installed the <TT>readline</TT> development package
+(which is probably named <TT>libreadline-dev</TT> or <TT>readline-devel</TT>).
+If you get link errors after that,
+then try "<KBD>make linux MYLIBS=-ltermcap</KBD>".
+
+<H3>Installing Lua</H3>
+<P>
+  Once you have built Lua, you may want to install it in an official
+  place in your system. In this case, do "<KBD>make install</KBD>". The official
+  place and the way to install files are defined in the <TT>Makefile</TT>. You'll
+  probably need the right permissions to install files.
+
+<P>
+  To build and install Lua in one step, do "<KBD>make xxx install</KBD>",
+  where xxx is your platform name.
+
+<P>
+  To install Lua locally, do "<KBD>make local</KBD>".
+  This will create a directory <TT>install</TT> with subdirectories
+  <TT>bin</TT>, <TT>include</TT>, <TT>lib</TT>, <TT>man</TT>, <TT>share</TT>,
+  and install Lua as listed below.
+
+  To install Lua locally, but in some other directory, do
+  "<KBD>make install INSTALL_TOP=xxx</KBD>", where xxx is your chosen directory.
+  The installation starts in the <TT>src</TT> and <TT>doc</TT> directories,
+  so take care if <TT>INSTALL_TOP</TT> is not an absolute path.
+
+<DL CLASS="display">
+<DT>
+    bin:
+<DD>
+    lua luac
+<DT>
+    include:
+<DD>
+    lua.h luaconf.h lualib.h lauxlib.h lua.hpp
+<DT>
+    lib:
+<DD>
+    liblua.a
+<DT>
+    man/man1:
+<DD>
+    lua.1 luac.1
+</DL>
+
+<P>
+  These are the only directories you need for development.
+  If you only want to run Lua programs,
+  you only need the files in <TT>bin</TT> and <TT>man</TT>.
+  The files in <TT>include</TT> and <TT>lib</TT> are needed for
+  embedding Lua in C or C++ programs.
+
+<H3><A NAME="customization">Customization</A></H3>
+<P>
+  Three kinds of things can be customized by editing a file:
+<UL>
+    <LI> Where and how to install Lua &mdash; edit <TT>Makefile</TT>.
+    <LI> How to build Lua &mdash; edit <TT>src/Makefile</TT>.
+    <LI> Lua features &mdash; edit <TT>src/luaconf.h</TT>.
+</UL>
+
+<P>
+  You don't actually need to edit the Makefiles because you may set the
+  relevant variables in the command line when invoking make.
+  Nevertheless, it's probably best to edit and save the Makefiles to
+  record the changes you've made.
+
+<P>
+  On the other hand, if you need to customize some Lua features, you'll need
+  to edit <TT>src/luaconf.h</TT> before building and installing Lua.
+  The edited file will be the one installed, and
+  it will be used by any Lua clients that you build, to ensure consistency.
+  Further customization is available to experts by editing the Lua sources.
+
+<H3><A NAME="other">Building Lua on other systems</A></H3>
+<P>
+  If you're not using the usual Unix tools, then the instructions for
+  building Lua depend on the compiler you use. You'll need to create
+  projects (or whatever your compiler uses) for building the library,
+  the interpreter, and the compiler, as follows:
+
+<DL CLASS="display">
+<DT>
+library:
+<DD>
+lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c
+lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c ltable.c
+ltm.c lundump.c lvm.c lzio.c
+lauxlib.c lbaselib.c lbitlib.c lcorolib.c ldblib.c liolib.c
+lmathlib.c loslib.c lstrlib.c ltablib.c lutf8lib.c loadlib.c linit.c
+<DT>
+interpreter:
+<DD>
+  library, lua.c
+<DT>
+compiler:
+<DD>
+  library, luac.c
+</DL>
+
+<P>
+  To use Lua as a library in your own programs you'll need to know how to
+  create and use libraries with your compiler. Moreover, to dynamically load
+  C libraries for Lua you'll need to know how to create dynamic libraries
+  and you'll need to make sure that the Lua API functions are accessible to
+  those dynamic libraries &mdash; but <EM>don't</EM> link the Lua library
+  into each dynamic library. For Unix, we recommend that the Lua library
+  be linked statically into the host program and its symbols exported for
+  dynamic linking; <TT>src/Makefile</TT> does this for the Lua interpreter.
+  For Windows, we recommend that the Lua library be a DLL.
+  In all cases, the compiler luac should be linked statically.
+
+<P>
+  As mentioned above, you may edit <TT>src/luaconf.h</TT> to customize
+  some features before building Lua.
+
+<H2><A NAME="changes">Changes since Lua 5.2</A></H2>
+<P>
+Here are the main changes introduced in Lua 5.3.
+The
+<A HREF="contents.html">reference manual</A>
+lists the
+<A HREF="manual.html#8">incompatibilities</A> that had to be introduced.
+
+<H3>Main changes</H3>
+<UL>
+<LI> integers (64-bit by default)
+<LI> official support for 32-bit numbers
+<LI> bitwise operators
+<LI> basic utf-8 support
+<LI> functions for packing and unpacking values
+
+</UL>
+
+Here are the other changes introduced in Lua 5.3:
+<H3>Language</H3>
+<UL>
+<LI> userdata can have any Lua value as uservalue
+<LI> floor division
+<LI> more flexible rules for some metamethods
+</UL>
+
+<H3>Libraries</H3>
+<UL>
+<LI> <CODE>ipairs</CODE> and the table library respect metamethods
+<LI> strip option in <CODE>string.dump</CODE>
+<LI> table library respects metamethods
+<LI> new function <CODE>table.move</CODE>
+<LI> new function <CODE>string.pack</CODE>
+<LI> new function <CODE>string.unpack</CODE>
+<LI> new function <CODE>string.packsize</CODE>
+</UL>
+
+<H3>C API</H3>
+<UL>
+<LI> simpler API for continuation functions in C
+<LI> <CODE>lua_gettable</CODE> and similar functions return type of resulted value
+<LI> strip option in <CODE>lua_dump</CODE>
+<LI> new function: <CODE>lua_geti</CODE>
+<LI> new function: <CODE>lua_seti</CODE>
+<LI> new function: <CODE>lua_isyieldable</CODE>
+<LI> new function: <CODE>lua_numbertointeger</CODE>
+<LI> new function: <CODE>lua_rotate</CODE>
+<LI> new function: <CODE>lua_stringtonumber</CODE>
+</UL>
+
+<H3>Lua standalone interpreter</H3>
+<UL>
+<LI> can be used as calculator; no need to prefix with '='
+<LI> <CODE>arg</CODE> table available to all code
+</UL>
+
+<H2><A NAME="license">License</A></H2>
+<P>
+<A HREF="http://www.opensource.org/docs/definition.php">
+<IMG SRC="osi-certified-72x60.png" ALIGN="right" ALT="[osi certified]" STYLE="padding-left: 30px ;">
+</A>
+Lua is free software distributed under the terms of the
+<A HREF="http://www.opensource.org/licenses/mit-license.html">MIT license</A>
+reproduced below;
+it may be used for any purpose, including commercial purposes,
+at absolutely no cost without having to ask us.
+
+The only requirement is that if you do use Lua,
+then you should give us credit by including the appropriate copyright notice somewhere in your product or its documentation.
+
+For details, see
+<A HREF="http://www.lua.org/license.html">this</A>.
+
+<BLOCKQUOTE STYLE="padding-bottom: 0em">
+Copyright &copy; 1994&ndash;2016 Lua.org, PUC-Rio.
+
+<P>
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+<P>
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+<P>
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+</BLOCKQUOTE>
+<P>
+
+<P CLASS="footer">
+Last update:
+Tue Feb  2 22:25:27 BRST 2016
+</P>
+<!--
+Last change: revised for Lua 5.3.3
+-->
+
+</BODY>
+</HTML>
diff --git a/src/Makefile b/src/Makefile
new file mode 100644
index 0000000..d71c75c
--- /dev/null
+++ b/src/Makefile
@@ -0,0 +1,197 @@
+# Makefile for building Lua
+# See ../doc/readme.html for installation and customization instructions.
+
+# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT =======================
+
+# Your platform. See PLATS for possible values.
+PLAT= none
+
+CC= gcc -std=gnu99
+CFLAGS= -O2 -Wall -Wextra -DLUA_COMPAT_5_2 $(SYSCFLAGS) $(MYCFLAGS)
+LDFLAGS= $(SYSLDFLAGS) $(MYLDFLAGS)
+LIBS= -lm $(SYSLIBS) $(MYLIBS)
+
+AR= ar rcu
+RANLIB= ranlib
+RM= rm -f
+
+SYSCFLAGS=
+SYSLDFLAGS=
+SYSLIBS=
+
+MYCFLAGS=
+MYLDFLAGS=
+MYLIBS=
+MYOBJS=
+
+# == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE =======
+
+PLATS= aix bsd c89 freebsd generic linux macosx mingw posix solaris
+
+LUA_A=	liblua.a
+CORE_O=	lapi.o lcode.o lctype.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o \
+	lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o \
+	ltm.o lundump.o lvm.o lzio.o
+LIB_O=	lauxlib.o lbaselib.o lbitlib.o lcorolib.o ldblib.o liolib.o \
+	lmathlib.o loslib.o lstrlib.o ltablib.o lutf8lib.o loadlib.o linit.o
+BASE_O= $(CORE_O) $(LIB_O) $(MYOBJS)
+
+LUA_T=	lua
+LUA_O=	lua.o
+
+LUAC_T=	luac
+LUAC_O=	luac.o
+
+ALL_O= $(BASE_O) $(LUA_O) $(LUAC_O)
+ALL_T= $(LUA_A) $(LUA_T) $(LUAC_T)
+ALL_A= $(LUA_A)
+
+# Targets start here.
+default: $(PLAT)
+
+all:	$(ALL_T)
+
+o:	$(ALL_O)
+
+a:	$(ALL_A)
+
+$(LUA_A): $(BASE_O)
+	$(AR) $@ $(BASE_O)
+	$(RANLIB) $@
+
+$(LUA_T): $(LUA_O) $(LUA_A)
+	$(CC) -o $@ $(LDFLAGS) $(LUA_O) $(LUA_A) $(LIBS)
+
+$(LUAC_T): $(LUAC_O) $(LUA_A)
+	$(CC) -o $@ $(LDFLAGS) $(LUAC_O) $(LUA_A) $(LIBS)
+
+clean:
+	$(RM) $(ALL_T) $(ALL_O)
+
+depend:
+	@$(CC) $(CFLAGS) -MM l*.c
+
+echo:
+	@echo "PLAT= $(PLAT)"
+	@echo "CC= $(CC)"
+	@echo "CFLAGS= $(CFLAGS)"
+	@echo "LDFLAGS= $(SYSLDFLAGS)"
+	@echo "LIBS= $(LIBS)"
+	@echo "AR= $(AR)"
+	@echo "RANLIB= $(RANLIB)"
+	@echo "RM= $(RM)"
+
+# Convenience targets for popular platforms
+ALL= all
+
+none:
+	@echo "Please do 'make PLATFORM' where PLATFORM is one of these:"
+	@echo "   $(PLATS)"
+
+aix:
+	$(MAKE) $(ALL) CC="xlc" CFLAGS="-O2 -DLUA_USE_POSIX -DLUA_USE_DLOPEN" SYSLIBS="-ldl" SYSLDFLAGS="-brtl -bexpall"
+
+bsd:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX -DLUA_USE_DLOPEN" SYSLIBS="-Wl,-E"
+
+c89:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_C89" CC="gcc -std=c89"
+	@echo ''
+	@echo '*** C89 does not guarantee 64-bit integers for Lua.'
+	@echo ''
+
+
+freebsd:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX" SYSLIBS="-Wl,-E -lreadline"
+
+generic: $(ALL)
+
+linux:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX" SYSLIBS="-Wl,-E -ldl -lreadline"
+
+macosx:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_MACOSX" SYSLIBS="-lreadline" CC=cc
+
+mingw:
+	$(MAKE) "LUA_A=lua53.dll" "LUA_T=lua.exe" \
+	"AR=$(CC) -shared -o" "RANLIB=strip --strip-unneeded" \
+	"SYSCFLAGS=-DLUA_BUILD_AS_DLL" "SYSLIBS=" "SYSLDFLAGS=-s" lua.exe
+	$(MAKE) "LUAC_T=luac.exe" luac.exe
+
+posix:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX"
+
+solaris:
+	$(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX -DLUA_USE_DLOPEN -D_REENTRANT" SYSLIBS="-ldl"
+
+# list targets that do not create files (but not all makes understand .PHONY)
+.PHONY: all $(PLATS) default o a clean depend echo none
+
+# DO NOT DELETE
+
+lapi.o: lapi.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \
+ lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h lstring.h \
+ ltable.h lundump.h lvm.h
+lauxlib.o: lauxlib.c lprefix.h lua.h luaconf.h lauxlib.h
+lbaselib.o: lbaselib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lbitlib.o: lbitlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lcode.o: lcode.c lprefix.h lua.h luaconf.h lcode.h llex.h lobject.h \
+ llimits.h lzio.h lmem.h lopcodes.h lparser.h ldebug.h lstate.h ltm.h \
+ ldo.h lgc.h lstring.h ltable.h lvm.h
+lcorolib.o: lcorolib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lctype.o: lctype.c lprefix.h lctype.h lua.h luaconf.h llimits.h
+ldblib.o: ldblib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+ldebug.o: ldebug.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \
+ lobject.h ltm.h lzio.h lmem.h lcode.h llex.h lopcodes.h lparser.h \
+ ldebug.h ldo.h lfunc.h lstring.h lgc.h ltable.h lvm.h
+ldo.o: ldo.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \
+ lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h lopcodes.h \
+ lparser.h lstring.h ltable.h lundump.h lvm.h
+ldump.o: ldump.c lprefix.h lua.h luaconf.h lobject.h llimits.h lstate.h \
+ ltm.h lzio.h lmem.h lundump.h
+lfunc.o: lfunc.c lprefix.h lua.h luaconf.h lfunc.h lobject.h llimits.h \
+ lgc.h lstate.h ltm.h lzio.h lmem.h
+lgc.o: lgc.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \
+ llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h lstring.h ltable.h
+linit.o: linit.c lprefix.h lua.h luaconf.h lualib.h lauxlib.h
+liolib.o: liolib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+llex.o: llex.c lprefix.h lua.h luaconf.h lctype.h llimits.h ldebug.h \
+ lstate.h lobject.h ltm.h lzio.h lmem.h ldo.h lgc.h llex.h lparser.h \
+ lstring.h ltable.h
+lmathlib.o: lmathlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lmem.o: lmem.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \
+ llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h
+loadlib.o: loadlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lobject.o: lobject.c lprefix.h lua.h luaconf.h lctype.h llimits.h \
+ ldebug.h lstate.h lobject.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h \
+ lvm.h
+lopcodes.o: lopcodes.c lprefix.h lopcodes.h llimits.h lua.h luaconf.h
+loslib.o: loslib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lparser.o: lparser.c lprefix.h lua.h luaconf.h lcode.h llex.h lobject.h \
+ llimits.h lzio.h lmem.h lopcodes.h lparser.h ldebug.h lstate.h ltm.h \
+ ldo.h lfunc.h lstring.h lgc.h ltable.h
+lstate.o: lstate.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \
+ lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h llex.h \
+ lstring.h ltable.h
+lstring.o: lstring.c lprefix.h lua.h luaconf.h ldebug.h lstate.h \
+ lobject.h llimits.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h
+lstrlib.o: lstrlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+ltable.o: ltable.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \
+ llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h lstring.h ltable.h lvm.h
+ltablib.o: ltablib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+ltm.o: ltm.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \
+ llimits.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h ltable.h lvm.h
+lua.o: lua.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+luac.o: luac.c lprefix.h lua.h luaconf.h lauxlib.h lobject.h llimits.h \
+ lstate.h ltm.h lzio.h lmem.h lundump.h ldebug.h lopcodes.h
+lundump.o: lundump.c lprefix.h lua.h luaconf.h ldebug.h lstate.h \
+ lobject.h llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lstring.h lgc.h \
+ lundump.h
+lutf8lib.o: lutf8lib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h
+lvm.o: lvm.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \
+ llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h lopcodes.h lstring.h \
+ ltable.h lvm.h
+lzio.o: lzio.c lprefix.h lua.h luaconf.h llimits.h lmem.h lstate.h \
+ lobject.h ltm.h lzio.h
+
+# (end of Makefile)
diff --git a/src/lapi.c b/src/lapi.c
new file mode 100644
index 0000000..c9455a5
--- /dev/null
+++ b/src/lapi.c
@@ -0,0 +1,1298 @@
+/*
+** $Id: lapi.c,v 2.259 2016/02/29 14:27:14 roberto Exp $
+** Lua API
+** See Copyright Notice in lua.h
+*/
+
+#define lapi_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stdarg.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lapi.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lundump.h"
+#include "lvm.h"
+
+
+
+const char lua_ident[] =
+  "$LuaVersion: " LUA_COPYRIGHT " $"
+  "$LuaAuthors: " LUA_AUTHORS " $";
+
+
+/* value at a non-valid index */
+#define NONVALIDVALUE		cast(TValue *, luaO_nilobject)
+
+/* corresponding test */
+#define isvalid(o)	((o) != luaO_nilobject)
+
+/* test for pseudo index */
+#define ispseudo(i)		((i) <= LUA_REGISTRYINDEX)
+
+/* test for upvalue */
+#define isupvalue(i)		((i) < LUA_REGISTRYINDEX)
+
+/* test for valid but not pseudo index */
+#define isstackindex(i, o)	(isvalid(o) && !ispseudo(i))
+
+#define api_checkvalidindex(l,o)  api_check(l, isvalid(o), "invalid index")
+
+#define api_checkstackindex(l, i, o)  \
+	api_check(l, isstackindex(i, o), "index not in the stack")
+
+
+static TValue *index2addr (lua_State *L, int idx) {
+  CallInfo *ci = L->ci;
+  if (idx > 0) {
+    TValue *o = ci->func + idx;
+    api_check(L, idx <= ci->top - (ci->func + 1), "unacceptable index");
+    if (o >= L->top) return NONVALIDVALUE;
+    else return o;
+  }
+  else if (!ispseudo(idx)) {  /* negative index */
+    api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
+    return L->top + idx;
+  }
+  else if (idx == LUA_REGISTRYINDEX)
+    return &G(L)->l_registry;
+  else {  /* upvalues */
+    idx = LUA_REGISTRYINDEX - idx;
+    api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
+    if (ttislcf(ci->func))  /* light C function? */
+      return NONVALIDVALUE;  /* it has no upvalues */
+    else {
+      CClosure *func = clCvalue(ci->func);
+      return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE;
+    }
+  }
+}
+
+
+/*
+** to be called by 'lua_checkstack' in protected mode, to grow stack
+** capturing memory errors
+*/
+static void growstack (lua_State *L, void *ud) {
+  int size = *(int *)ud;
+  luaD_growstack(L, size);
+}
+
+
+LUA_API int lua_checkstack (lua_State *L, int n) {
+  int res;
+  CallInfo *ci = L->ci;
+  lua_lock(L);
+  api_check(L, n >= 0, "negative 'n'");
+  if (L->stack_last - L->top > n)  /* stack large enough? */
+    res = 1;  /* yes; check is OK */
+  else {  /* no; need to grow stack */
+    int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
+    if (inuse > LUAI_MAXSTACK - n)  /* can grow without overflow? */
+      res = 0;  /* no */
+    else  /* try to grow stack */
+      res = (luaD_rawrunprotected(L, &growstack, &n) == LUA_OK);
+  }
+  if (res && ci->top < L->top + n)
+    ci->top = L->top + n;  /* adjust frame top */
+  lua_unlock(L);
+  return res;
+}
+
+
+LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
+  int i;
+  if (from == to) return;
+  lua_lock(to);
+  api_checknelems(from, n);
+  api_check(from, G(from) == G(to), "moving among independent states");
+  api_check(from, to->ci->top - to->top >= n, "stack overflow");
+  from->top -= n;
+  for (i = 0; i < n; i++) {
+    setobj2s(to, to->top, from->top + i);
+    to->top++;  /* stack already checked by previous 'api_check' */
+  }
+  lua_unlock(to);
+}
+
+
+LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
+  lua_CFunction old;
+  lua_lock(L);
+  old = G(L)->panic;
+  G(L)->panic = panicf;
+  lua_unlock(L);
+  return old;
+}
+
+
+LUA_API const lua_Number *lua_version (lua_State *L) {
+  static const lua_Number version = LUA_VERSION_NUM;
+  if (L == NULL) return &version;
+  else return G(L)->version;
+}
+
+
+
+/*
+** basic stack manipulation
+*/
+
+
+/*
+** convert an acceptable stack index into an absolute index
+*/
+LUA_API int lua_absindex (lua_State *L, int idx) {
+  return (idx > 0 || ispseudo(idx))
+         ? idx
+         : cast_int(L->top - L->ci->func) + idx;
+}
+
+
+LUA_API int lua_gettop (lua_State *L) {
+  return cast_int(L->top - (L->ci->func + 1));
+}
+
+
+LUA_API void lua_settop (lua_State *L, int idx) {
+  StkId func = L->ci->func;
+  lua_lock(L);
+  if (idx >= 0) {
+    api_check(L, idx <= L->stack_last - (func + 1), "new top too large");
+    while (L->top < (func + 1) + idx)
+      setnilvalue(L->top++);
+    L->top = (func + 1) + idx;
+  }
+  else {
+    api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
+    L->top += idx+1;  /* 'subtract' index (index is negative) */
+  }
+  lua_unlock(L);
+}
+
+
+/*
+** Reverse the stack segment from 'from' to 'to'
+** (auxiliary to 'lua_rotate')
+*/
+static void reverse (lua_State *L, StkId from, StkId to) {
+  for (; from < to; from++, to--) {
+    TValue temp;
+    setobj(L, &temp, from);
+    setobjs2s(L, from, to);
+    setobj2s(L, to, &temp);
+  }
+}
+
+
+/*
+** Let x = AB, where A is a prefix of length 'n'. Then,
+** rotate x n == BA. But BA == (A^r . B^r)^r.
+*/
+LUA_API void lua_rotate (lua_State *L, int idx, int n) {
+  StkId p, t, m;
+  lua_lock(L);
+  t = L->top - 1;  /* end of stack segment being rotated */
+  p = index2addr(L, idx);  /* start of segment */
+  api_checkstackindex(L, idx, p);
+  api_check(L, (n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'");
+  m = (n >= 0 ? t - n : p - n - 1);  /* end of prefix */
+  reverse(L, p, m);  /* reverse the prefix with length 'n' */
+  reverse(L, m + 1, t);  /* reverse the suffix */
+  reverse(L, p, t);  /* reverse the entire segment */
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
+  TValue *fr, *to;
+  lua_lock(L);
+  fr = index2addr(L, fromidx);
+  to = index2addr(L, toidx);
+  api_checkvalidindex(L, to);
+  setobj(L, to, fr);
+  if (isupvalue(toidx))  /* function upvalue? */
+    luaC_barrier(L, clCvalue(L->ci->func), fr);
+  /* LUA_REGISTRYINDEX does not need gc barrier
+     (collector revisits it before finishing collection) */
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushvalue (lua_State *L, int idx) {
+  lua_lock(L);
+  setobj2s(L, L->top, index2addr(L, idx));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+
+/*
+** access functions (stack -> C)
+*/
+
+
+LUA_API int lua_type (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  return (isvalid(o) ? ttnov(o) : LUA_TNONE);
+}
+
+
+LUA_API const char *lua_typename (lua_State *L, int t) {
+  UNUSED(L);
+  api_check(L, LUA_TNONE <= t && t < LUA_NUMTAGS, "invalid tag");
+  return ttypename(t);
+}
+
+
+LUA_API int lua_iscfunction (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  return (ttislcf(o) || (ttisCclosure(o)));
+}
+
+
+LUA_API int lua_isinteger (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  return ttisinteger(o);
+}
+
+
+LUA_API int lua_isnumber (lua_State *L, int idx) {
+  lua_Number n;
+  const TValue *o = index2addr(L, idx);
+  return tonumber(o, &n);
+}
+
+
+LUA_API int lua_isstring (lua_State *L, int idx) {
+  const TValue *o = index2addr(L, idx);
+  return (ttisstring(o) || cvt2str(o));
+}
+
+
+LUA_API int lua_isuserdata (lua_State *L, int idx) {
+  const TValue *o = index2addr(L, idx);
+  return (ttisfulluserdata(o) || ttislightuserdata(o));
+}
+
+
+LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
+  StkId o1 = index2addr(L, index1);
+  StkId o2 = index2addr(L, index2);
+  return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0;
+}
+
+
+LUA_API void lua_arith (lua_State *L, int op) {
+  lua_lock(L);
+  if (op != LUA_OPUNM && op != LUA_OPBNOT)
+    api_checknelems(L, 2);  /* all other operations expect two operands */
+  else {  /* for unary operations, add fake 2nd operand */
+    api_checknelems(L, 1);
+    setobjs2s(L, L->top, L->top - 1);
+    api_incr_top(L);
+  }
+  /* first operand at top - 2, second at top - 1; result go to top - 2 */
+  luaO_arith(L, op, L->top - 2, L->top - 1, L->top - 2);
+  L->top--;  /* remove second operand */
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
+  StkId o1, o2;
+  int i = 0;
+  lua_lock(L);  /* may call tag method */
+  o1 = index2addr(L, index1);
+  o2 = index2addr(L, index2);
+  if (isvalid(o1) && isvalid(o2)) {
+    switch (op) {
+      case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break;
+      case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
+      case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break;
+      default: api_check(L, 0, "invalid option");
+    }
+  }
+  lua_unlock(L);
+  return i;
+}
+
+
+LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) {
+  size_t sz = luaO_str2num(s, L->top);
+  if (sz != 0)
+    api_incr_top(L);
+  return sz;
+}
+
+
+LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) {
+  lua_Number n;
+  const TValue *o = index2addr(L, idx);
+  int isnum = tonumber(o, &n);
+  if (!isnum)
+    n = 0;  /* call to 'tonumber' may change 'n' even if it fails */
+  if (pisnum) *pisnum = isnum;
+  return n;
+}
+
+
+LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum) {
+  lua_Integer res;
+  const TValue *o = index2addr(L, idx);
+  int isnum = tointeger(o, &res);
+  if (!isnum)
+    res = 0;  /* call to 'tointeger' may change 'n' even if it fails */
+  if (pisnum) *pisnum = isnum;
+  return res;
+}
+
+
+LUA_API int lua_toboolean (lua_State *L, int idx) {
+  const TValue *o = index2addr(L, idx);
+  return !l_isfalse(o);
+}
+
+
+LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
+  StkId o = index2addr(L, idx);
+  if (!ttisstring(o)) {
+    if (!cvt2str(o)) {  /* not convertible? */
+      if (len != NULL) *len = 0;
+      return NULL;
+    }
+    lua_lock(L);  /* 'luaO_tostring' may create a new string */
+    luaO_tostring(L, o);
+    luaC_checkGC(L);
+    o = index2addr(L, idx);  /* previous call may reallocate the stack */
+    lua_unlock(L);
+  }
+  if (len != NULL)
+    *len = vslen(o);
+  return svalue(o);
+}
+
+
+LUA_API size_t lua_rawlen (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  switch (ttype(o)) {
+    case LUA_TSHRSTR: return tsvalue(o)->shrlen;
+    case LUA_TLNGSTR: return tsvalue(o)->u.lnglen;
+    case LUA_TUSERDATA: return uvalue(o)->len;
+    case LUA_TTABLE: return luaH_getn(hvalue(o));
+    default: return 0;
+  }
+}
+
+
+LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  if (ttislcf(o)) return fvalue(o);
+  else if (ttisCclosure(o))
+    return clCvalue(o)->f;
+  else return NULL;  /* not a C function */
+}
+
+
+LUA_API void *lua_touserdata (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  switch (ttnov(o)) {
+    case LUA_TUSERDATA: return getudatamem(uvalue(o));
+    case LUA_TLIGHTUSERDATA: return pvalue(o);
+    default: return NULL;
+  }
+}
+
+
+LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  return (!ttisthread(o)) ? NULL : thvalue(o);
+}
+
+
+LUA_API const void *lua_topointer (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  switch (ttype(o)) {
+    case LUA_TTABLE: return hvalue(o);
+    case LUA_TLCL: return clLvalue(o);
+    case LUA_TCCL: return clCvalue(o);
+    case LUA_TLCF: return cast(void *, cast(size_t, fvalue(o)));
+    case LUA_TTHREAD: return thvalue(o);
+    case LUA_TUSERDATA: return getudatamem(uvalue(o));
+    case LUA_TLIGHTUSERDATA: return pvalue(o);
+    default: return NULL;
+  }
+}
+
+
+
+/*
+** push functions (C -> stack)
+*/
+
+
+LUA_API void lua_pushnil (lua_State *L) {
+  lua_lock(L);
+  setnilvalue(L->top);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
+  lua_lock(L);
+  setfltvalue(L->top, n);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
+  lua_lock(L);
+  setivalue(L->top, n);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+/*
+** Pushes on the stack a string with given length. Avoid using 's' when
+** 'len' == 0 (as 's' can be NULL in that case), due to later use of
+** 'memcmp' and 'memcpy'.
+*/
+LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
+  TString *ts;
+  lua_lock(L);
+  ts = (len == 0) ? luaS_new(L, "") : luaS_newlstr(L, s, len);
+  setsvalue2s(L, L->top, ts);
+  api_incr_top(L);
+  luaC_checkGC(L);
+  lua_unlock(L);
+  return getstr(ts);
+}
+
+
+LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
+  lua_lock(L);
+  if (s == NULL)
+    setnilvalue(L->top);
+  else {
+    TString *ts;
+    ts = luaS_new(L, s);
+    setsvalue2s(L, L->top, ts);
+    s = getstr(ts);  /* internal copy's address */
+  }
+  api_incr_top(L);
+  luaC_checkGC(L);
+  lua_unlock(L);
+  return s;
+}
+
+
+LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
+                                      va_list argp) {
+  const char *ret;
+  lua_lock(L);
+  ret = luaO_pushvfstring(L, fmt, argp);
+  luaC_checkGC(L);
+  lua_unlock(L);
+  return ret;
+}
+
+
+LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
+  const char *ret;
+  va_list argp;
+  lua_lock(L);
+  va_start(argp, fmt);
+  ret = luaO_pushvfstring(L, fmt, argp);
+  va_end(argp);
+  luaC_checkGC(L);
+  lua_unlock(L);
+  return ret;
+}
+
+
+LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
+  lua_lock(L);
+  if (n == 0) {
+    setfvalue(L->top, fn);
+  }
+  else {
+    CClosure *cl;
+    api_checknelems(L, n);
+    api_check(L, n <= MAXUPVAL, "upvalue index too large");
+    cl = luaF_newCclosure(L, n);
+    cl->f = fn;
+    L->top -= n;
+    while (n--) {
+      setobj2n(L, &cl->upvalue[n], L->top + n);
+      /* does not need barrier because closure is white */
+    }
+    setclCvalue(L, L->top, cl);
+  }
+  api_incr_top(L);
+  luaC_checkGC(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushboolean (lua_State *L, int b) {
+  lua_lock(L);
+  setbvalue(L->top, (b != 0));  /* ensure that true is 1 */
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
+  lua_lock(L);
+  setpvalue(L->top, p);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_pushthread (lua_State *L) {
+  lua_lock(L);
+  setthvalue(L, L->top, L);
+  api_incr_top(L);
+  lua_unlock(L);
+  return (G(L)->mainthread == L);
+}
+
+
+
+/*
+** get functions (Lua -> stack)
+*/
+
+
+static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
+  const TValue *slot;
+  TString *str = luaS_new(L, k);
+  if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
+    setobj2s(L, L->top, slot);
+    api_incr_top(L);
+  }
+  else {
+    setsvalue2s(L, L->top, str);
+    api_incr_top(L);
+    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
+  }
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+LUA_API int lua_getglobal (lua_State *L, const char *name) {
+  Table *reg = hvalue(&G(L)->l_registry);
+  lua_lock(L);
+  return auxgetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
+}
+
+
+LUA_API int lua_gettable (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  luaV_gettable(L, t, L->top - 1, L->top - 1);
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+LUA_API int lua_getfield (lua_State *L, int idx, const char *k) {
+  lua_lock(L);
+  return auxgetstr(L, index2addr(L, idx), k);
+}
+
+
+LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
+  StkId t;
+  const TValue *slot;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  if (luaV_fastget(L, t, n, slot, luaH_getint)) {
+    setobj2s(L, L->top, slot);
+    api_incr_top(L);
+  }
+  else {
+    setivalue(L->top, n);
+    api_incr_top(L);
+    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
+  }
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+LUA_API int lua_rawget (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+LUA_API int lua_rawgeti (lua_State *L, int idx, lua_Integer n) {
+  StkId t;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  setobj2s(L, L->top, luaH_getint(hvalue(t), n));
+  api_incr_top(L);
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
+  StkId t;
+  TValue k;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  setpvalue(&k, cast(void *, p));
+  setobj2s(L, L->top, luaH_get(hvalue(t), &k));
+  api_incr_top(L);
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
+  Table *t;
+  lua_lock(L);
+  t = luaH_new(L);
+  sethvalue(L, L->top, t);
+  api_incr_top(L);
+  if (narray > 0 || nrec > 0)
+    luaH_resize(L, t, narray, nrec);
+  luaC_checkGC(L);
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_getmetatable (lua_State *L, int objindex) {
+  const TValue *obj;
+  Table *mt;
+  int res = 0;
+  lua_lock(L);
+  obj = index2addr(L, objindex);
+  switch (ttnov(obj)) {
+    case LUA_TTABLE:
+      mt = hvalue(obj)->metatable;
+      break;
+    case LUA_TUSERDATA:
+      mt = uvalue(obj)->metatable;
+      break;
+    default:
+      mt = G(L)->mt[ttnov(obj)];
+      break;
+  }
+  if (mt != NULL) {
+    sethvalue(L, L->top, mt);
+    api_incr_top(L);
+    res = 1;
+  }
+  lua_unlock(L);
+  return res;
+}
+
+
+LUA_API int lua_getuservalue (lua_State *L, int idx) {
+  StkId o;
+  lua_lock(L);
+  o = index2addr(L, idx);
+  api_check(L, ttisfulluserdata(o), "full userdata expected");
+  getuservalue(L, uvalue(o), L->top);
+  api_incr_top(L);
+  lua_unlock(L);
+  return ttnov(L->top - 1);
+}
+
+
+/*
+** set functions (stack -> Lua)
+*/
+
+/*
+** t[k] = value at the top of the stack (where 'k' is a string)
+*/
+static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
+  const TValue *slot;
+  TString *str = luaS_new(L, k);
+  api_checknelems(L, 1);
+  if (luaV_fastset(L, t, str, slot, luaH_getstr, L->top - 1))
+    L->top--;  /* pop value */
+  else {
+    setsvalue2s(L, L->top, str);  /* push 'str' (to make it a TValue) */
+    api_incr_top(L);
+    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
+    L->top -= 2;  /* pop value and key */
+  }
+  lua_unlock(L);  /* lock done by caller */
+}
+
+
+LUA_API void lua_setglobal (lua_State *L, const char *name) {
+  Table *reg = hvalue(&G(L)->l_registry);
+  lua_lock(L);  /* unlock done in 'auxsetstr' */
+  auxsetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
+}
+
+
+LUA_API void lua_settable (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  api_checknelems(L, 2);
+  t = index2addr(L, idx);
+  luaV_settable(L, t, L->top - 2, L->top - 1);
+  L->top -= 2;  /* pop index and value */
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
+  lua_lock(L);  /* unlock done in 'auxsetstr' */
+  auxsetstr(L, index2addr(L, idx), k);
+}
+
+
+LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
+  StkId t;
+  const TValue *slot;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  t = index2addr(L, idx);
+  if (luaV_fastset(L, t, n, slot, luaH_getint, L->top - 1))
+    L->top--;  /* pop value */
+  else {
+    setivalue(L->top, n);
+    api_incr_top(L);
+    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
+    L->top -= 2;  /* pop value and key */
+  }
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_rawset (lua_State *L, int idx) {
+  StkId o;
+  TValue *slot;
+  lua_lock(L);
+  api_checknelems(L, 2);
+  o = index2addr(L, idx);
+  api_check(L, ttistable(o), "table expected");
+  slot = luaH_set(L, hvalue(o), L->top - 2);
+  setobj2t(L, slot, L->top - 1);
+  invalidateTMcache(hvalue(o));
+  luaC_barrierback(L, hvalue(o), L->top-1);
+  L->top -= 2;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
+  StkId o;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = index2addr(L, idx);
+  api_check(L, ttistable(o), "table expected");
+  luaH_setint(L, hvalue(o), n, L->top - 1);
+  luaC_barrierback(L, hvalue(o), L->top-1);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
+  StkId o;
+  TValue k, *slot;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = index2addr(L, idx);
+  api_check(L, ttistable(o), "table expected");
+  setpvalue(&k, cast(void *, p));
+  slot = luaH_set(L, hvalue(o), &k);
+  setobj2t(L, slot, L->top - 1);
+  luaC_barrierback(L, hvalue(o), L->top - 1);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_setmetatable (lua_State *L, int objindex) {
+  TValue *obj;
+  Table *mt;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  obj = index2addr(L, objindex);
+  if (ttisnil(L->top - 1))
+    mt = NULL;
+  else {
+    api_check(L, ttistable(L->top - 1), "table expected");
+    mt = hvalue(L->top - 1);
+  }
+  switch (ttnov(obj)) {
+    case LUA_TTABLE: {
+      hvalue(obj)->metatable = mt;
+      if (mt) {
+        luaC_objbarrier(L, gcvalue(obj), mt);
+        luaC_checkfinalizer(L, gcvalue(obj), mt);
+      }
+      break;
+    }
+    case LUA_TUSERDATA: {
+      uvalue(obj)->metatable = mt;
+      if (mt) {
+        luaC_objbarrier(L, uvalue(obj), mt);
+        luaC_checkfinalizer(L, gcvalue(obj), mt);
+      }
+      break;
+    }
+    default: {
+      G(L)->mt[ttnov(obj)] = mt;
+      break;
+    }
+  }
+  L->top--;
+  lua_unlock(L);
+  return 1;
+}
+
+
+LUA_API void lua_setuservalue (lua_State *L, int idx) {
+  StkId o;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = index2addr(L, idx);
+  api_check(L, ttisfulluserdata(o), "full userdata expected");
+  setuservalue(L, uvalue(o), L->top - 1);
+  luaC_barrier(L, gcvalue(o), L->top - 1);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+/*
+** 'load' and 'call' functions (run Lua code)
+*/
+
+
+#define checkresults(L,na,nr) \
+     api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \
+	"results from function overflow current stack size")
+
+
+LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
+                        lua_KContext ctx, lua_KFunction k) {
+  StkId func;
+  lua_lock(L);
+  api_check(L, k == NULL || !isLua(L->ci),
+    "cannot use continuations inside hooks");
+  api_checknelems(L, nargs+1);
+  api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
+  checkresults(L, nargs, nresults);
+  func = L->top - (nargs+1);
+  if (k != NULL && L->nny == 0) {  /* need to prepare continuation? */
+    L->ci->u.c.k = k;  /* save continuation */
+    L->ci->u.c.ctx = ctx;  /* save context */
+    luaD_call(L, func, nresults);  /* do the call */
+  }
+  else  /* no continuation or no yieldable */
+    luaD_callnoyield(L, func, nresults);  /* just do the call */
+  adjustresults(L, nresults);
+  lua_unlock(L);
+}
+
+
+
+/*
+** Execute a protected call.
+*/
+struct CallS {  /* data to 'f_call' */
+  StkId func;
+  int nresults;
+};
+
+
+static void f_call (lua_State *L, void *ud) {
+  struct CallS *c = cast(struct CallS *, ud);
+  luaD_callnoyield(L, c->func, c->nresults);
+}
+
+
+
+LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
+                        lua_KContext ctx, lua_KFunction k) {
+  struct CallS c;
+  int status;
+  ptrdiff_t func;
+  lua_lock(L);
+  api_check(L, k == NULL || !isLua(L->ci),
+    "cannot use continuations inside hooks");
+  api_checknelems(L, nargs+1);
+  api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
+  checkresults(L, nargs, nresults);
+  if (errfunc == 0)
+    func = 0;
+  else {
+    StkId o = index2addr(L, errfunc);
+    api_checkstackindex(L, errfunc, o);
+    func = savestack(L, o);
+  }
+  c.func = L->top - (nargs+1);  /* function to be called */
+  if (k == NULL || L->nny > 0) {  /* no continuation or no yieldable? */
+    c.nresults = nresults;  /* do a 'conventional' protected call */
+    status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
+  }
+  else {  /* prepare continuation (call is already protected by 'resume') */
+    CallInfo *ci = L->ci;
+    ci->u.c.k = k;  /* save continuation */
+    ci->u.c.ctx = ctx;  /* save context */
+    /* save information for error recovery */
+    ci->extra = savestack(L, c.func);
+    ci->u.c.old_errfunc = L->errfunc;
+    L->errfunc = func;
+    setoah(ci->callstatus, L->allowhook);  /* save value of 'allowhook' */
+    ci->callstatus |= CIST_YPCALL;  /* function can do error recovery */
+    luaD_call(L, c.func, nresults);  /* do the call */
+    ci->callstatus &= ~CIST_YPCALL;
+    L->errfunc = ci->u.c.old_errfunc;
+    status = LUA_OK;  /* if it is here, there were no errors */
+  }
+  adjustresults(L, nresults);
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
+                      const char *chunkname, const char *mode) {
+  ZIO z;
+  int status;
+  lua_lock(L);
+  if (!chunkname) chunkname = "?";
+  luaZ_init(L, &z, reader, data);
+  status = luaD_protectedparser(L, &z, chunkname, mode);
+  if (status == LUA_OK) {  /* no errors? */
+    LClosure *f = clLvalue(L->top - 1);  /* get newly created function */
+    if (f->nupvalues >= 1) {  /* does it have an upvalue? */
+      /* get global table from registry */
+      Table *reg = hvalue(&G(L)->l_registry);
+      const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
+      /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
+      setobj(L, f->upvals[0]->v, gt);
+      luaC_upvalbarrier(L, f->upvals[0]);
+    }
+  }
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) {
+  int status;
+  TValue *o;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = L->top - 1;
+  if (isLfunction(o))
+    status = luaU_dump(L, getproto(o), writer, data, strip);
+  else
+    status = 1;
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_status (lua_State *L) {
+  return L->status;
+}
+
+
+/*
+** Garbage-collection function
+*/
+
+LUA_API int lua_gc (lua_State *L, int what, int data) {
+  int res = 0;
+  global_State *g;
+  lua_lock(L);
+  g = G(L);
+  switch (what) {
+    case LUA_GCSTOP: {
+      g->gcrunning = 0;
+      break;
+    }
+    case LUA_GCRESTART: {
+      luaE_setdebt(g, 0);
+      g->gcrunning = 1;
+      break;
+    }
+    case LUA_GCCOLLECT: {
+      luaC_fullgc(L, 0);
+      break;
+    }
+    case LUA_GCCOUNT: {
+      /* GC values are expressed in Kbytes: #bytes/2^10 */
+      res = cast_int(gettotalbytes(g) >> 10);
+      break;
+    }
+    case LUA_GCCOUNTB: {
+      res = cast_int(gettotalbytes(g) & 0x3ff);
+      break;
+    }
+    case LUA_GCSTEP: {
+      l_mem debt = 1;  /* =1 to signal that it did an actual step */
+      lu_byte oldrunning = g->gcrunning;
+      g->gcrunning = 1;  /* allow GC to run */
+      if (data == 0) {
+        luaE_setdebt(g, -GCSTEPSIZE);  /* to do a "small" step */
+        luaC_step(L);
+      }
+      else {  /* add 'data' to total debt */
+        debt = cast(l_mem, data) * 1024 + g->GCdebt;
+        luaE_setdebt(g, debt);
+        luaC_checkGC(L);
+      }
+      g->gcrunning = oldrunning;  /* restore previous state */
+      if (debt > 0 && g->gcstate == GCSpause)  /* end of cycle? */
+        res = 1;  /* signal it */
+      break;
+    }
+    case LUA_GCSETPAUSE: {
+      res = g->gcpause;
+      g->gcpause = data;
+      break;
+    }
+    case LUA_GCSETSTEPMUL: {
+      res = g->gcstepmul;
+      if (data < 40) data = 40;  /* avoid ridiculous low values (and 0) */
+      g->gcstepmul = data;
+      break;
+    }
+    case LUA_GCISRUNNING: {
+      res = g->gcrunning;
+      break;
+    }
+    default: res = -1;  /* invalid option */
+  }
+  lua_unlock(L);
+  return res;
+}
+
+
+
+/*
+** miscellaneous functions
+*/
+
+
+LUA_API int lua_error (lua_State *L) {
+  lua_lock(L);
+  api_checknelems(L, 1);
+  luaG_errormsg(L);
+  /* code unreachable; will unlock when control actually leaves the kernel */
+  return 0;  /* to avoid warnings */
+}
+
+
+LUA_API int lua_next (lua_State *L, int idx) {
+  StkId t;
+  int more;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  more = luaH_next(L, hvalue(t), L->top - 1);
+  if (more) {
+    api_incr_top(L);
+  }
+  else  /* no more elements */
+    L->top -= 1;  /* remove key */
+  lua_unlock(L);
+  return more;
+}
+
+
+LUA_API void lua_concat (lua_State *L, int n) {
+  lua_lock(L);
+  api_checknelems(L, n);
+  if (n >= 2) {
+    luaV_concat(L, n);
+  }
+  else if (n == 0) {  /* push empty string */
+    setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
+    api_incr_top(L);
+  }
+  /* else n == 1; nothing to do */
+  luaC_checkGC(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_len (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  luaV_objlen(L, L->top, t);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
+  lua_Alloc f;
+  lua_lock(L);
+  if (ud) *ud = G(L)->ud;
+  f = G(L)->frealloc;
+  lua_unlock(L);
+  return f;
+}
+
+
+LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
+  lua_lock(L);
+  G(L)->ud = ud;
+  G(L)->frealloc = f;
+  lua_unlock(L);
+}
+
+
+LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
+  Udata *u;
+  lua_lock(L);
+  u = luaS_newudata(L, size);
+  setuvalue(L, L->top, u);
+  api_incr_top(L);
+  luaC_checkGC(L);
+  lua_unlock(L);
+  return getudatamem(u);
+}
+
+
+
+static const char *aux_upvalue (StkId fi, int n, TValue **val,
+                                CClosure **owner, UpVal **uv) {
+  switch (ttype(fi)) {
+    case LUA_TCCL: {  /* C closure */
+      CClosure *f = clCvalue(fi);
+      if (!(1 <= n && n <= f->nupvalues)) return NULL;
+      *val = &f->upvalue[n-1];
+      if (owner) *owner = f;
+      return "";
+    }
+    case LUA_TLCL: {  /* Lua closure */
+      LClosure *f = clLvalue(fi);
+      TString *name;
+      Proto *p = f->p;
+      if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
+      *val = f->upvals[n-1]->v;
+      if (uv) *uv = f->upvals[n - 1];
+      name = p->upvalues[n-1].name;
+      return (name == NULL) ? "(*no name)" : getstr(name);
+    }
+    default: return NULL;  /* not a closure */
+  }
+}
+
+
+LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
+  const char *name;
+  TValue *val = NULL;  /* to avoid warnings */
+  lua_lock(L);
+  name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL, NULL);
+  if (name) {
+    setobj2s(L, L->top, val);
+    api_incr_top(L);
+  }
+  lua_unlock(L);
+  return name;
+}
+
+
+LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
+  const char *name;
+  TValue *val = NULL;  /* to avoid warnings */
+  CClosure *owner = NULL;
+  UpVal *uv = NULL;
+  StkId fi;
+  lua_lock(L);
+  fi = index2addr(L, funcindex);
+  api_checknelems(L, 1);
+  name = aux_upvalue(fi, n, &val, &owner, &uv);
+  if (name) {
+    L->top--;
+    setobj(L, val, L->top);
+    if (owner) { luaC_barrier(L, owner, L->top); }
+    else if (uv) { luaC_upvalbarrier(L, uv); }
+  }
+  lua_unlock(L);
+  return name;
+}
+
+
+static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
+  LClosure *f;
+  StkId fi = index2addr(L, fidx);
+  api_check(L, ttisLclosure(fi), "Lua function expected");
+  f = clLvalue(fi);
+  api_check(L, (1 <= n && n <= f->p->sizeupvalues), "invalid upvalue index");
+  if (pf) *pf = f;
+  return &f->upvals[n - 1];  /* get its upvalue pointer */
+}
+
+
+LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
+  StkId fi = index2addr(L, fidx);
+  switch (ttype(fi)) {
+    case LUA_TLCL: {  /* lua closure */
+      return *getupvalref(L, fidx, n, NULL);
+    }
+    case LUA_TCCL: {  /* C closure */
+      CClosure *f = clCvalue(fi);
+      api_check(L, 1 <= n && n <= f->nupvalues, "invalid upvalue index");
+      return &f->upvalue[n - 1];
+    }
+    default: {
+      api_check(L, 0, "closure expected");
+      return NULL;
+    }
+  }
+}
+
+
+LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
+                                            int fidx2, int n2) {
+  LClosure *f1;
+  UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
+  UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
+  luaC_upvdeccount(L, *up1);
+  *up1 = *up2;
+  (*up1)->refcount++;
+  if (upisopen(*up1)) (*up1)->u.open.touched = 1;
+  luaC_upvalbarrier(L, *up1);
+}
+
+
diff --git a/src/lapi.h b/src/lapi.h
new file mode 100644
index 0000000..6d36dee
--- /dev/null
+++ b/src/lapi.h
@@ -0,0 +1,24 @@
+/*
+** $Id: lapi.h,v 2.9 2015/03/06 19:49:50 roberto Exp $
+** Auxiliary functions from Lua API
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lapi_h
+#define lapi_h
+
+
+#include "llimits.h"
+#include "lstate.h"
+
+#define api_incr_top(L)   {L->top++; api_check(L, L->top <= L->ci->top, \
+				"stack overflow");}
+
+#define adjustresults(L,nres) \
+    { if ((nres) == LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; }
+
+#define api_checknelems(L,n)	api_check(L, (n) < (L->top - L->ci->func), \
+				  "not enough elements in the stack")
+
+
+#endif
diff --git a/src/lauxlib.c b/src/lauxlib.c
new file mode 100644
index 0000000..bacf43b
--- /dev/null
+++ b/src/lauxlib.c
@@ -0,0 +1,1035 @@
+/*
+** $Id: lauxlib.c,v 1.286 2016/01/08 15:33:09 roberto Exp $
+** Auxiliary functions for building Lua libraries
+** See Copyright Notice in lua.h
+*/
+
+#define lauxlib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/*
+** This file uses only the official API of Lua.
+** Any function declared here could be written as an application function.
+*/
+
+#include "lua.h"
+
+#include "lauxlib.h"
+
+
+/*
+** {======================================================
+** Traceback
+** =======================================================
+*/
+
+
+#define LEVELS1	10	/* size of the first part of the stack */
+#define LEVELS2	11	/* size of the second part of the stack */
+
+
+
+/*
+** search for 'objidx' in table at index -1.
+** return 1 + string at top if find a good name.
+*/
+static int findfield (lua_State *L, int objidx, int level) {
+  if (level == 0 || !lua_istable(L, -1))
+    return 0;  /* not found */
+  lua_pushnil(L);  /* start 'next' loop */
+  while (lua_next(L, -2)) {  /* for each pair in table */
+    if (lua_type(L, -2) == LUA_TSTRING) {  /* ignore non-string keys */
+      if (lua_rawequal(L, objidx, -1)) {  /* found object? */
+        lua_pop(L, 1);  /* remove value (but keep name) */
+        return 1;
+      }
+      else if (findfield(L, objidx, level - 1)) {  /* try recursively */
+        lua_remove(L, -2);  /* remove table (but keep name) */
+        lua_pushliteral(L, ".");
+        lua_insert(L, -2);  /* place '.' between the two names */
+        lua_concat(L, 3);
+        return 1;
+      }
+    }
+    lua_pop(L, 1);  /* remove value */
+  }
+  return 0;  /* not found */
+}
+
+
+/*
+** Search for a name for a function in all loaded modules
+** (registry._LOADED).
+*/
+static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
+  int top = lua_gettop(L);
+  lua_getinfo(L, "f", ar);  /* push function */
+  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+  if (findfield(L, top + 1, 2)) {
+    const char *name = lua_tostring(L, -1);
+    if (strncmp(name, "_G.", 3) == 0) {  /* name start with '_G.'? */
+      lua_pushstring(L, name + 3);  /* push name without prefix */
+      lua_remove(L, -2);  /* remove original name */
+    }
+    lua_copy(L, -1, top + 1);  /* move name to proper place */
+    lua_pop(L, 2);  /* remove pushed values */
+    return 1;
+  }
+  else {
+    lua_settop(L, top);  /* remove function and global table */
+    return 0;
+  }
+}
+
+
+static void pushfuncname (lua_State *L, lua_Debug *ar) {
+  if (pushglobalfuncname(L, ar)) {  /* try first a global name */
+    lua_pushfstring(L, "function '%s'", lua_tostring(L, -1));
+    lua_remove(L, -2);  /* remove name */
+  }
+  else if (*ar->namewhat != '\0')  /* is there a name from code? */
+    lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name);  /* use it */
+  else if (*ar->what == 'm')  /* main? */
+      lua_pushliteral(L, "main chunk");
+  else if (*ar->what != 'C')  /* for Lua functions, use <file:line> */
+    lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
+  else  /* nothing left... */
+    lua_pushliteral(L, "?");
+}
+
+
+static int lastlevel (lua_State *L) {
+  lua_Debug ar;
+  int li = 1, le = 1;
+  /* find an upper bound */
+  while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }
+  /* do a binary search */
+  while (li < le) {
+    int m = (li + le)/2;
+    if (lua_getstack(L, m, &ar)) li = m + 1;
+    else le = m;
+  }
+  return le - 1;
+}
+
+
+LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
+                                const char *msg, int level) {
+  lua_Debug ar;
+  int top = lua_gettop(L);
+  int last = lastlevel(L1);
+  int n1 = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
+  if (msg)
+    lua_pushfstring(L, "%s\n", msg);
+  luaL_checkstack(L, 10, NULL);
+  lua_pushliteral(L, "stack traceback:");
+  while (lua_getstack(L1, level++, &ar)) {
+    if (n1-- == 0) {  /* too many levels? */
+      lua_pushliteral(L, "\n\t...");  /* add a '...' */
+      level = last - LEVELS2 + 1;  /* and skip to last ones */
+    }
+    else {
+      lua_getinfo(L1, "Slnt", &ar);
+      lua_pushfstring(L, "\n\t%s:", ar.short_src);
+      if (ar.currentline > 0)
+        lua_pushfstring(L, "%d:", ar.currentline);
+      lua_pushliteral(L, " in ");
+      pushfuncname(L, &ar);
+      if (ar.istailcall)
+        lua_pushliteral(L, "\n\t(...tail calls...)");
+      lua_concat(L, lua_gettop(L) - top);
+    }
+  }
+  lua_concat(L, lua_gettop(L) - top);
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Error-report functions
+** =======================================================
+*/
+
+LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {
+  lua_Debug ar;
+  if (!lua_getstack(L, 0, &ar))  /* no stack frame? */
+    return luaL_error(L, "bad argument #%d (%s)", arg, extramsg);
+  lua_getinfo(L, "n", &ar);
+  if (strcmp(ar.namewhat, "method") == 0) {
+    arg--;  /* do not count 'self' */
+    if (arg == 0)  /* error is in the self argument itself? */
+      return luaL_error(L, "calling '%s' on bad self (%s)",
+                           ar.name, extramsg);
+  }
+  if (ar.name == NULL)
+    ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?";
+  return luaL_error(L, "bad argument #%d to '%s' (%s)",
+                        arg, ar.name, extramsg);
+}
+
+
+static int typeerror (lua_State *L, int arg, const char *tname) {
+  const char *msg;
+  const char *typearg;  /* name for the type of the actual argument */
+  if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
+    typearg = lua_tostring(L, -1);  /* use the given type name */
+  else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA)
+    typearg = "light userdata";  /* special name for messages */
+  else
+    typearg = luaL_typename(L, arg);  /* standard name */
+  msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg);
+  return luaL_argerror(L, arg, msg);
+}
+
+
+static void tag_error (lua_State *L, int arg, int tag) {
+  typeerror(L, arg, lua_typename(L, tag));
+}
+
+
+/*
+** The use of 'lua_pushfstring' ensures this function does not
+** need reserved stack space when called.
+*/
+LUALIB_API void luaL_where (lua_State *L, int level) {
+  lua_Debug ar;
+  if (lua_getstack(L, level, &ar)) {  /* check function at level */
+    lua_getinfo(L, "Sl", &ar);  /* get info about it */
+    if (ar.currentline > 0) {  /* is there info? */
+      lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
+      return;
+    }
+  }
+  lua_pushfstring(L, "");  /* else, no information available... */
+}
+
+
+/*
+** Again, the use of 'lua_pushvfstring' ensures this function does
+** not need reserved stack space when called. (At worst, it generates
+** an error with "stack overflow" instead of the given message.)
+*/
+LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
+  va_list argp;
+  va_start(argp, fmt);
+  luaL_where(L, 1);
+  lua_pushvfstring(L, fmt, argp);
+  va_end(argp);
+  lua_concat(L, 2);
+  return lua_error(L);
+}
+
+
+LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
+  int en = errno;  /* calls to Lua API may change this value */
+  if (stat) {
+    lua_pushboolean(L, 1);
+    return 1;
+  }
+  else {
+    lua_pushnil(L);
+    if (fname)
+      lua_pushfstring(L, "%s: %s", fname, strerror(en));
+    else
+      lua_pushstring(L, strerror(en));
+    lua_pushinteger(L, en);
+    return 3;
+  }
+}
+
+
+#if !defined(l_inspectstat)	/* { */
+
+#if defined(LUA_USE_POSIX)
+
+#include <sys/wait.h>
+
+/*
+** use appropriate macros to interpret 'pclose' return status
+*/
+#define l_inspectstat(stat,what)  \
+   if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \
+   else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }
+
+#else
+
+#define l_inspectstat(stat,what)  /* no op */
+
+#endif
+
+#endif				/* } */
+
+
+LUALIB_API int luaL_execresult (lua_State *L, int stat) {
+  const char *what = "exit";  /* type of termination */
+  if (stat == -1)  /* error? */
+    return luaL_fileresult(L, 0, NULL);
+  else {
+    l_inspectstat(stat, what);  /* interpret result */
+    if (*what == 'e' && stat == 0)  /* successful termination? */
+      lua_pushboolean(L, 1);
+    else
+      lua_pushnil(L);
+    lua_pushstring(L, what);
+    lua_pushinteger(L, stat);
+    return 3;  /* return true/nil,what,code */
+  }
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Userdata's metatable manipulation
+** =======================================================
+*/
+
+LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
+  if (luaL_getmetatable(L, tname) != LUA_TNIL)  /* name already in use? */
+    return 0;  /* leave previous value on top, but return 0 */
+  lua_pop(L, 1);
+  lua_createtable(L, 0, 2);  /* create metatable */
+  lua_pushstring(L, tname);
+  lua_setfield(L, -2, "__name");  /* metatable.__name = tname */
+  lua_pushvalue(L, -1);
+  lua_setfield(L, LUA_REGISTRYINDEX, tname);  /* registry.name = metatable */
+  return 1;
+}
+
+
+LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) {
+  luaL_getmetatable(L, tname);
+  lua_setmetatable(L, -2);
+}
+
+
+LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) {
+  void *p = lua_touserdata(L, ud);
+  if (p != NULL) {  /* value is a userdata? */
+    if (lua_getmetatable(L, ud)) {  /* does it have a metatable? */
+      luaL_getmetatable(L, tname);  /* get correct metatable */
+      if (!lua_rawequal(L, -1, -2))  /* not the same? */
+        p = NULL;  /* value is a userdata with wrong metatable */
+      lua_pop(L, 2);  /* remove both metatables */
+      return p;
+    }
+  }
+  return NULL;  /* value is not a userdata with a metatable */
+}
+
+
+LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
+  void *p = luaL_testudata(L, ud, tname);
+  if (p == NULL) typeerror(L, ud, tname);
+  return p;
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Argument check functions
+** =======================================================
+*/
+
+LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
+                                 const char *const lst[]) {
+  const char *name = (def) ? luaL_optstring(L, arg, def) :
+                             luaL_checkstring(L, arg);
+  int i;
+  for (i=0; lst[i]; i++)
+    if (strcmp(lst[i], name) == 0)
+      return i;
+  return luaL_argerror(L, arg,
+                       lua_pushfstring(L, "invalid option '%s'", name));
+}
+
+
+/*
+** Ensures the stack has at least 'space' extra slots, raising an error
+** if it cannot fulfill the request. (The error handling needs a few
+** extra slots to format the error message. In case of an error without
+** this extra space, Lua will generate the same 'stack overflow' error,
+** but without 'msg'.)
+*/
+LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
+  if (!lua_checkstack(L, space)) {
+    if (msg)
+      luaL_error(L, "stack overflow (%s)", msg);
+    else
+      luaL_error(L, "stack overflow");
+  }
+}
+
+
+LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) {
+  if (lua_type(L, arg) != t)
+    tag_error(L, arg, t);
+}
+
+
+LUALIB_API void luaL_checkany (lua_State *L, int arg) {
+  if (lua_type(L, arg) == LUA_TNONE)
+    luaL_argerror(L, arg, "value expected");
+}
+
+
+LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) {
+  const char *s = lua_tolstring(L, arg, len);
+  if (!s) tag_error(L, arg, LUA_TSTRING);
+  return s;
+}
+
+
+LUALIB_API const char *luaL_optlstring (lua_State *L, int arg,
+                                        const char *def, size_t *len) {
+  if (lua_isnoneornil(L, arg)) {
+    if (len)
+      *len = (def ? strlen(def) : 0);
+    return def;
+  }
+  else return luaL_checklstring(L, arg, len);
+}
+
+
+LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) {
+  int isnum;
+  lua_Number d = lua_tonumberx(L, arg, &isnum);
+  if (!isnum)
+    tag_error(L, arg, LUA_TNUMBER);
+  return d;
+}
+
+
+LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) {
+  return luaL_opt(L, luaL_checknumber, arg, def);
+}
+
+
+static void interror (lua_State *L, int arg) {
+  if (lua_isnumber(L, arg))
+    luaL_argerror(L, arg, "number has no integer representation");
+  else
+    tag_error(L, arg, LUA_TNUMBER);
+}
+
+
+LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) {
+  int isnum;
+  lua_Integer d = lua_tointegerx(L, arg, &isnum);
+  if (!isnum) {
+    interror(L, arg);
+  }
+  return d;
+}
+
+
+LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg,
+                                                      lua_Integer def) {
+  return luaL_opt(L, luaL_checkinteger, arg, def);
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Generic Buffer manipulation
+** =======================================================
+*/
+
+/* userdata to box arbitrary data */
+typedef struct UBox {
+  void *box;
+  size_t bsize;
+} UBox;
+
+
+static void *resizebox (lua_State *L, int idx, size_t newsize) {
+  void *ud;
+  lua_Alloc allocf = lua_getallocf(L, &ud);
+  UBox *box = (UBox *)lua_touserdata(L, idx);
+  void *temp = allocf(ud, box->box, box->bsize, newsize);
+  if (temp == NULL && newsize > 0) {  /* allocation error? */
+    resizebox(L, idx, 0);  /* free buffer */
+    luaL_error(L, "not enough memory for buffer allocation");
+  }
+  box->box = temp;
+  box->bsize = newsize;
+  return temp;
+}
+
+
+static int boxgc (lua_State *L) {
+  resizebox(L, 1, 0);
+  return 0;
+}
+
+
+static void *newbox (lua_State *L, size_t newsize) {
+  UBox *box = (UBox *)lua_newuserdata(L, sizeof(UBox));
+  box->box = NULL;
+  box->bsize = 0;
+  if (luaL_newmetatable(L, "LUABOX")) {  /* creating metatable? */
+    lua_pushcfunction(L, boxgc);
+    lua_setfield(L, -2, "__gc");  /* metatable.__gc = boxgc */
+  }
+  lua_setmetatable(L, -2);
+  return resizebox(L, -1, newsize);
+}
+
+
+/*
+** check whether buffer is using a userdata on the stack as a temporary
+** buffer
+*/
+#define buffonstack(B)	((B)->b != (B)->initb)
+
+
+/*
+** returns a pointer to a free area with at least 'sz' bytes
+*/
+LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
+  lua_State *L = B->L;
+  if (B->size - B->n < sz) {  /* not enough space? */
+    char *newbuff;
+    size_t newsize = B->size * 2;  /* double buffer size */
+    if (newsize - B->n < sz)  /* not big enough? */
+      newsize = B->n + sz;
+    if (newsize < B->n || newsize - B->n < sz)
+      luaL_error(L, "buffer too large");
+    /* create larger buffer */
+    if (buffonstack(B))
+      newbuff = (char *)resizebox(L, -1, newsize);
+    else {  /* no buffer yet */
+      newbuff = (char *)newbox(L, newsize);
+      memcpy(newbuff, B->b, B->n * sizeof(char));  /* copy original content */
+    }
+    B->b = newbuff;
+    B->size = newsize;
+  }
+  return &B->b[B->n];
+}
+
+
+LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
+  if (l > 0) {  /* avoid 'memcpy' when 's' can be NULL */
+    char *b = luaL_prepbuffsize(B, l);
+    memcpy(b, s, l * sizeof(char));
+    luaL_addsize(B, l);
+  }
+}
+
+
+LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
+  luaL_addlstring(B, s, strlen(s));
+}
+
+
+LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
+  lua_State *L = B->L;
+  lua_pushlstring(L, B->b, B->n);
+  if (buffonstack(B)) {
+    resizebox(L, -2, 0);  /* delete old buffer */
+    lua_remove(L, -2);  /* remove its header from the stack */
+  }
+}
+
+
+LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
+  luaL_addsize(B, sz);
+  luaL_pushresult(B);
+}
+
+
+LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
+  lua_State *L = B->L;
+  size_t l;
+  const char *s = lua_tolstring(L, -1, &l);
+  if (buffonstack(B))
+    lua_insert(L, -2);  /* put value below buffer */
+  luaL_addlstring(B, s, l);
+  lua_remove(L, (buffonstack(B)) ? -2 : -1);  /* remove value */
+}
+
+
+LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
+  B->L = L;
+  B->b = B->initb;
+  B->n = 0;
+  B->size = LUAL_BUFFERSIZE;
+}
+
+
+LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
+  luaL_buffinit(L, B);
+  return luaL_prepbuffsize(B, sz);
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Reference system
+** =======================================================
+*/
+
+/* index of free-list header */
+#define freelist	0
+
+
+LUALIB_API int luaL_ref (lua_State *L, int t) {
+  int ref;
+  if (lua_isnil(L, -1)) {
+    lua_pop(L, 1);  /* remove from stack */
+    return LUA_REFNIL;  /* 'nil' has a unique fixed reference */
+  }
+  t = lua_absindex(L, t);
+  lua_rawgeti(L, t, freelist);  /* get first free element */
+  ref = (int)lua_tointeger(L, -1);  /* ref = t[freelist] */
+  lua_pop(L, 1);  /* remove it from stack */
+  if (ref != 0) {  /* any free element? */
+    lua_rawgeti(L, t, ref);  /* remove it from list */
+    lua_rawseti(L, t, freelist);  /* (t[freelist] = t[ref]) */
+  }
+  else  /* no free elements */
+    ref = (int)lua_rawlen(L, t) + 1;  /* get a new reference */
+  lua_rawseti(L, t, ref);
+  return ref;
+}
+
+
+LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
+  if (ref >= 0) {
+    t = lua_absindex(L, t);
+    lua_rawgeti(L, t, freelist);
+    lua_rawseti(L, t, ref);  /* t[ref] = t[freelist] */
+    lua_pushinteger(L, ref);
+    lua_rawseti(L, t, freelist);  /* t[freelist] = ref */
+  }
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Load functions
+** =======================================================
+*/
+
+typedef struct LoadF {
+  int n;  /* number of pre-read characters */
+  FILE *f;  /* file being read */
+  char buff[BUFSIZ];  /* area for reading file */
+} LoadF;
+
+
+static const char *getF (lua_State *L, void *ud, size_t *size) {
+  LoadF *lf = (LoadF *)ud;
+  (void)L;  /* not used */
+  if (lf->n > 0) {  /* are there pre-read characters to be read? */
+    *size = lf->n;  /* return them (chars already in buffer) */
+    lf->n = 0;  /* no more pre-read characters */
+  }
+  else {  /* read a block from file */
+    /* 'fread' can return > 0 *and* set the EOF flag. If next call to
+       'getF' called 'fread', it might still wait for user input.
+       The next check avoids this problem. */
+    if (feof(lf->f)) return NULL;
+    *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);  /* read block */
+  }
+  return lf->buff;
+}
+
+
+static int errfile (lua_State *L, const char *what, int fnameindex) {
+  const char *serr = strerror(errno);
+  const char *filename = lua_tostring(L, fnameindex) + 1;
+  lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
+  lua_remove(L, fnameindex);
+  return LUA_ERRFILE;
+}
+
+
+static int skipBOM (LoadF *lf) {
+  const char *p = "\xEF\xBB\xBF";  /* UTF-8 BOM mark */
+  int c;
+  lf->n = 0;
+  do {
+    c = getc(lf->f);
+    if (c == EOF || c != *(const unsigned char *)p++) return c;
+    lf->buff[lf->n++] = c;  /* to be read by the parser */
+  } while (*p != '\0');
+  lf->n = 0;  /* prefix matched; discard it */
+  return getc(lf->f);  /* return next character */
+}
+
+
+/*
+** reads the first character of file 'f' and skips an optional BOM mark
+** in its beginning plus its first line if it starts with '#'. Returns
+** true if it skipped the first line.  In any case, '*cp' has the
+** first "valid" character of the file (after the optional BOM and
+** a first-line comment).
+*/
+static int skipcomment (LoadF *lf, int *cp) {
+  int c = *cp = skipBOM(lf);
+  if (c == '#') {  /* first line is a comment (Unix exec. file)? */
+    do {  /* skip first line */
+      c = getc(lf->f);
+    } while (c != EOF && c != '\n');
+    *cp = getc(lf->f);  /* skip end-of-line, if present */
+    return 1;  /* there was a comment */
+  }
+  else return 0;  /* no comment */
+}
+
+
+LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
+                                             const char *mode) {
+  LoadF lf;
+  int status, readstatus;
+  int c;
+  int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */
+  if (filename == NULL) {
+    lua_pushliteral(L, "=stdin");
+    lf.f = stdin;
+  }
+  else {
+    lua_pushfstring(L, "@%s", filename);
+    lf.f = fopen(filename, "r");
+    if (lf.f == NULL) return errfile(L, "open", fnameindex);
+  }
+  if (skipcomment(&lf, &c))  /* read initial portion */
+    lf.buff[lf.n++] = '\n';  /* add line to correct line numbers */
+  if (c == LUA_SIGNATURE[0] && filename) {  /* binary file? */
+    lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */
+    if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
+    skipcomment(&lf, &c);  /* re-read initial portion */
+  }
+  if (c != EOF)
+    lf.buff[lf.n++] = c;  /* 'c' is the first character of the stream */
+  status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
+  readstatus = ferror(lf.f);
+  if (filename) fclose(lf.f);  /* close file (even in case of errors) */
+  if (readstatus) {
+    lua_settop(L, fnameindex);  /* ignore results from 'lua_load' */
+    return errfile(L, "read", fnameindex);
+  }
+  lua_remove(L, fnameindex);
+  return status;
+}
+
+
+typedef struct LoadS {
+  const char *s;
+  size_t size;
+} LoadS;
+
+
+static const char *getS (lua_State *L, void *ud, size_t *size) {
+  LoadS *ls = (LoadS *)ud;
+  (void)L;  /* not used */
+  if (ls->size == 0) return NULL;
+  *size = ls->size;
+  ls->size = 0;
+  return ls->s;
+}
+
+
+LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size,
+                                 const char *name, const char *mode) {
+  LoadS ls;
+  ls.s = buff;
+  ls.size = size;
+  return lua_load(L, getS, &ls, name, mode);
+}
+
+
+LUALIB_API int luaL_loadstring (lua_State *L, const char *s) {
+  return luaL_loadbuffer(L, s, strlen(s), s);
+}
+
+/* }====================================================== */
+
+
+
+LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
+  if (!lua_getmetatable(L, obj))  /* no metatable? */
+    return LUA_TNIL;
+  else {
+    int tt;
+    lua_pushstring(L, event);
+    tt = lua_rawget(L, -2);
+    if (tt == LUA_TNIL)  /* is metafield nil? */
+      lua_pop(L, 2);  /* remove metatable and metafield */
+    else
+      lua_remove(L, -2);  /* remove only metatable */
+    return tt;  /* return metafield type */
+  }
+}
+
+
+LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
+  obj = lua_absindex(L, obj);
+  if (luaL_getmetafield(L, obj, event) == LUA_TNIL)  /* no metafield? */
+    return 0;
+  lua_pushvalue(L, obj);
+  lua_call(L, 1, 1);
+  return 1;
+}
+
+
+LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
+  lua_Integer l;
+  int isnum;
+  lua_len(L, idx);
+  l = lua_tointegerx(L, -1, &isnum);
+  if (!isnum)
+    luaL_error(L, "object length is not an integer");
+  lua_pop(L, 1);  /* remove object */
+  return l;
+}
+
+
+LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
+  if (!luaL_callmeta(L, idx, "__tostring")) {  /* no metafield? */
+    switch (lua_type(L, idx)) {
+      case LUA_TNUMBER: {
+        if (lua_isinteger(L, idx))
+          lua_pushfstring(L, "%I", lua_tointeger(L, idx));
+        else
+          lua_pushfstring(L, "%f", lua_tonumber(L, idx));
+        break;
+      }
+      case LUA_TSTRING:
+        lua_pushvalue(L, idx);
+        break;
+      case LUA_TBOOLEAN:
+        lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false"));
+        break;
+      case LUA_TNIL:
+        lua_pushliteral(L, "nil");
+        break;
+      default:
+        lua_pushfstring(L, "%s: %p", luaL_typename(L, idx),
+                                            lua_topointer(L, idx));
+        break;
+    }
+  }
+  return lua_tolstring(L, -1, len);
+}
+
+
+/*
+** {======================================================
+** Compatibility with 5.1 module functions
+** =======================================================
+*/
+#if defined(LUA_COMPAT_MODULE)
+
+static const char *luaL_findtable (lua_State *L, int idx,
+                                   const char *fname, int szhint) {
+  const char *e;
+  if (idx) lua_pushvalue(L, idx);
+  do {
+    e = strchr(fname, '.');
+    if (e == NULL) e = fname + strlen(fname);
+    lua_pushlstring(L, fname, e - fname);
+    if (lua_rawget(L, -2) == LUA_TNIL) {  /* no such field? */
+      lua_pop(L, 1);  /* remove this nil */
+      lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
+      lua_pushlstring(L, fname, e - fname);
+      lua_pushvalue(L, -2);
+      lua_settable(L, -4);  /* set new table into field */
+    }
+    else if (!lua_istable(L, -1)) {  /* field has a non-table value? */
+      lua_pop(L, 2);  /* remove table and value */
+      return fname;  /* return problematic part of the name */
+    }
+    lua_remove(L, -2);  /* remove previous table */
+    fname = e + 1;
+  } while (*e == '.');
+  return NULL;
+}
+
+
+/*
+** Count number of elements in a luaL_Reg list.
+*/
+static int libsize (const luaL_Reg *l) {
+  int size = 0;
+  for (; l && l->name; l++) size++;
+  return size;
+}
+
+
+/*
+** Find or create a module table with a given name. The function
+** first looks at the _LOADED table and, if that fails, try a
+** global variable with that name. In any case, leaves on the stack
+** the module table.
+*/
+LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname,
+                                 int sizehint) {
+  luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);  /* get _LOADED table */
+  if (lua_getfield(L, -1, modname) != LUA_TTABLE) {  /* no _LOADED[modname]? */
+    lua_pop(L, 1);  /* remove previous result */
+    /* try global variable (and create one if it does not exist) */
+    lua_pushglobaltable(L);
+    if (luaL_findtable(L, 0, modname, sizehint) != NULL)
+      luaL_error(L, "name conflict for module '%s'", modname);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -3, modname);  /* _LOADED[modname] = new table */
+  }
+  lua_remove(L, -2);  /* remove _LOADED table */
+}
+
+
+LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
+                               const luaL_Reg *l, int nup) {
+  luaL_checkversion(L);
+  if (libname) {
+    luaL_pushmodule(L, libname, libsize(l));  /* get/create library table */
+    lua_insert(L, -(nup + 1));  /* move library table to below upvalues */
+  }
+  if (l)
+    luaL_setfuncs(L, l, nup);
+  else
+    lua_pop(L, nup);  /* remove upvalues */
+}
+
+#endif
+/* }====================================================== */
+
+/*
+** set functions from list 'l' into table at top - 'nup'; each
+** function gets the 'nup' elements at the top as upvalues.
+** Returns with only the table at the stack.
+*/
+LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
+  luaL_checkstack(L, nup, "too many upvalues");
+  for (; l->name != NULL; l++) {  /* fill the table with given functions */
+    int i;
+    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+      lua_pushvalue(L, -nup);
+    lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    lua_setfield(L, -(nup + 2), l->name);
+  }
+  lua_pop(L, nup);  /* remove upvalues */
+}
+
+
+/*
+** ensure that stack[idx][fname] has a table and push that table
+** into the stack
+*/
+LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
+  if (lua_getfield(L, idx, fname) == LUA_TTABLE)
+    return 1;  /* table already there */
+  else {
+    lua_pop(L, 1);  /* remove previous result */
+    idx = lua_absindex(L, idx);
+    lua_newtable(L);
+    lua_pushvalue(L, -1);  /* copy to be left at top */
+    lua_setfield(L, idx, fname);  /* assign new table to field */
+    return 0;  /* false, because did not find table there */
+  }
+}
+
+
+/*
+** Stripped-down 'require': After checking "loaded" table, calls 'openf'
+** to open a module, registers the result in 'package.loaded' table and,
+** if 'glb' is true, also registers the result in the global table.
+** Leaves resulting module on the top.
+*/
+LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
+                               lua_CFunction openf, int glb) {
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_getfield(L, -1, modname);  /* _LOADED[modname] */
+  if (!lua_toboolean(L, -1)) {  /* package not already loaded? */
+    lua_pop(L, 1);  /* remove field */
+    lua_pushcfunction(L, openf);
+    lua_pushstring(L, modname);  /* argument to open function */
+    lua_call(L, 1, 1);  /* call 'openf' to open module */
+    lua_pushvalue(L, -1);  /* make copy of module (call result) */
+    lua_setfield(L, -3, modname);  /* _LOADED[modname] = module */
+  }
+  lua_remove(L, -2);  /* remove _LOADED table */
+  if (glb) {
+    lua_pushvalue(L, -1);  /* copy of module */
+    lua_setglobal(L, modname);  /* _G[modname] = module */
+  }
+}
+
+
+LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
+                                                               const char *r) {
+  const char *wild;
+  size_t l = strlen(p);
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  while ((wild = strstr(s, p)) != NULL) {
+    luaL_addlstring(&b, s, wild - s);  /* push prefix */
+    luaL_addstring(&b, r);  /* push replacement in place of pattern */
+    s = wild + l;  /* continue after 'p' */
+  }
+  luaL_addstring(&b, s);  /* push last suffix */
+  luaL_pushresult(&b);
+  return lua_tostring(L, -1);
+}
+
+
+static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
+  (void)ud; (void)osize;  /* not used */
+  if (nsize == 0) {
+    free(ptr);
+    return NULL;
+  }
+  else
+    return realloc(ptr, nsize);
+}
+
+
+static int panic (lua_State *L) {
+  lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
+                        lua_tostring(L, -1));
+  return 0;  /* return to Lua to abort */
+}
+
+
+LUALIB_API lua_State *luaL_newstate (void) {
+  lua_State *L = lua_newstate(l_alloc, NULL);
+  if (L) lua_atpanic(L, &panic);
+  return L;
+}
+
+
+LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
+  const lua_Number *v = lua_version(L);
+  if (sz != LUAL_NUMSIZES)  /* check numeric types */
+    luaL_error(L, "core and library have incompatible numeric types");
+  if (v != lua_version(NULL))
+    luaL_error(L, "multiple Lua VMs detected");
+  else if (*v != ver)
+    luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
+                  ver, *v);
+}
+
diff --git a/src/lauxlib.h b/src/lauxlib.h
new file mode 100644
index 0000000..ddb7c22
--- /dev/null
+++ b/src/lauxlib.h
@@ -0,0 +1,256 @@
+/*
+** $Id: lauxlib.h,v 1.129 2015/11/23 11:29:43 roberto Exp $
+** Auxiliary functions for building Lua libraries
+** See Copyright Notice in lua.h
+*/
+
+
+#ifndef lauxlib_h
+#define lauxlib_h
+
+
+#include <stddef.h>
+#include <stdio.h>
+
+#include "lua.h"
+
+
+
+/* extra error code for 'luaL_load' */
+#define LUA_ERRFILE     (LUA_ERRERR+1)
+
+
+typedef struct luaL_Reg {
+  const char *name;
+  lua_CFunction func;
+} luaL_Reg;
+
+
+#define LUAL_NUMSIZES	(sizeof(lua_Integer)*16 + sizeof(lua_Number))
+
+LUALIB_API void (luaL_checkversion_) (lua_State *L, lua_Number ver, size_t sz);
+#define luaL_checkversion(L)  \
+	  luaL_checkversion_(L, LUA_VERSION_NUM, LUAL_NUMSIZES)
+
+LUALIB_API int (luaL_getmetafield) (lua_State *L, int obj, const char *e);
+LUALIB_API int (luaL_callmeta) (lua_State *L, int obj, const char *e);
+LUALIB_API const char *(luaL_tolstring) (lua_State *L, int idx, size_t *len);
+LUALIB_API int (luaL_argerror) (lua_State *L, int arg, const char *extramsg);
+LUALIB_API const char *(luaL_checklstring) (lua_State *L, int arg,
+                                                          size_t *l);
+LUALIB_API const char *(luaL_optlstring) (lua_State *L, int arg,
+                                          const char *def, size_t *l);
+LUALIB_API lua_Number (luaL_checknumber) (lua_State *L, int arg);
+LUALIB_API lua_Number (luaL_optnumber) (lua_State *L, int arg, lua_Number def);
+
+LUALIB_API lua_Integer (luaL_checkinteger) (lua_State *L, int arg);
+LUALIB_API lua_Integer (luaL_optinteger) (lua_State *L, int arg,
+                                          lua_Integer def);
+
+LUALIB_API void (luaL_checkstack) (lua_State *L, int sz, const char *msg);
+LUALIB_API void (luaL_checktype) (lua_State *L, int arg, int t);
+LUALIB_API void (luaL_checkany) (lua_State *L, int arg);
+
+LUALIB_API int   (luaL_newmetatable) (lua_State *L, const char *tname);
+LUALIB_API void  (luaL_setmetatable) (lua_State *L, const char *tname);
+LUALIB_API void *(luaL_testudata) (lua_State *L, int ud, const char *tname);
+LUALIB_API void *(luaL_checkudata) (lua_State *L, int ud, const char *tname);
+
+LUALIB_API void (luaL_where) (lua_State *L, int lvl);
+LUALIB_API int (luaL_error) (lua_State *L, const char *fmt, ...);
+
+LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def,
+                                   const char *const lst[]);
+
+LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname);
+LUALIB_API int (luaL_execresult) (lua_State *L, int stat);
+
+/* predefined references */
+#define LUA_NOREF       (-2)
+#define LUA_REFNIL      (-1)
+
+LUALIB_API int (luaL_ref) (lua_State *L, int t);
+LUALIB_API void (luaL_unref) (lua_State *L, int t, int ref);
+
+LUALIB_API int (luaL_loadfilex) (lua_State *L, const char *filename,
+                                               const char *mode);
+
+#define luaL_loadfile(L,f)	luaL_loadfilex(L,f,NULL)
+
+LUALIB_API int (luaL_loadbufferx) (lua_State *L, const char *buff, size_t sz,
+                                   const char *name, const char *mode);
+LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s);
+
+LUALIB_API lua_State *(luaL_newstate) (void);
+
+LUALIB_API lua_Integer (luaL_len) (lua_State *L, int idx);
+
+LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s, const char *p,
+                                                  const char *r);
+
+LUALIB_API void (luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup);
+
+LUALIB_API int (luaL_getsubtable) (lua_State *L, int idx, const char *fname);
+
+LUALIB_API void (luaL_traceback) (lua_State *L, lua_State *L1,
+                                  const char *msg, int level);
+
+LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
+                                 lua_CFunction openf, int glb);
+
+/*
+** ===============================================================
+** some useful macros
+** ===============================================================
+*/
+
+
+#define luaL_newlibtable(L,l)	\
+  lua_createtable(L, 0, sizeof(l)/sizeof((l)[0]) - 1)
+
+#define luaL_newlib(L,l)  \
+  (luaL_checkversion(L), luaL_newlibtable(L,l), luaL_setfuncs(L,l,0))
+
+#define luaL_argcheck(L, cond,arg,extramsg)	\
+		((void)((cond) || luaL_argerror(L, (arg), (extramsg))))
+#define luaL_checkstring(L,n)	(luaL_checklstring(L, (n), NULL))
+#define luaL_optstring(L,n,d)	(luaL_optlstring(L, (n), (d), NULL))
+
+#define luaL_typename(L,i)	lua_typename(L, lua_type(L,(i)))
+
+#define luaL_dofile(L, fn) \
+	(luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0))
+
+#define luaL_dostring(L, s) \
+	(luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0))
+
+#define luaL_getmetatable(L,n)	(lua_getfield(L, LUA_REGISTRYINDEX, (n)))
+
+#define luaL_opt(L,f,n,d)	(lua_isnoneornil(L,(n)) ? (d) : f(L,(n)))
+
+#define luaL_loadbuffer(L,s,sz,n)	luaL_loadbufferx(L,s,sz,n,NULL)
+
+
+/*
+** {======================================================
+** Generic Buffer manipulation
+** =======================================================
+*/
+
+typedef struct luaL_Buffer {
+  char *b;  /* buffer address */
+  size_t size;  /* buffer size */
+  size_t n;  /* number of characters in buffer */
+  lua_State *L;
+  char initb[LUAL_BUFFERSIZE];  /* initial buffer */
+} luaL_Buffer;
+
+
+#define luaL_addchar(B,c) \
+  ((void)((B)->n < (B)->size || luaL_prepbuffsize((B), 1)), \
+   ((B)->b[(B)->n++] = (c)))
+
+#define luaL_addsize(B,s)	((B)->n += (s))
+
+LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B);
+LUALIB_API char *(luaL_prepbuffsize) (luaL_Buffer *B, size_t sz);
+LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l);
+LUALIB_API void (luaL_addstring) (luaL_Buffer *B, const char *s);
+LUALIB_API void (luaL_addvalue) (luaL_Buffer *B);
+LUALIB_API void (luaL_pushresult) (luaL_Buffer *B);
+LUALIB_API void (luaL_pushresultsize) (luaL_Buffer *B, size_t sz);
+LUALIB_API char *(luaL_buffinitsize) (lua_State *L, luaL_Buffer *B, size_t sz);
+
+#define luaL_prepbuffer(B)	luaL_prepbuffsize(B, LUAL_BUFFERSIZE)
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** File handles for IO library
+** =======================================================
+*/
+
+/*
+** A file handle is a userdata with metatable 'LUA_FILEHANDLE' and
+** initial structure 'luaL_Stream' (it may contain other fields
+** after that initial structure).
+*/
+
+#define LUA_FILEHANDLE          "FILE*"
+
+
+typedef struct luaL_Stream {
+  FILE *f;  /* stream (NULL for incompletely created streams) */
+  lua_CFunction closef;  /* to close stream (NULL for closed streams) */
+} luaL_Stream;
+
+/* }====================================================== */
+
+
+
+/* compatibility with old module system */
+#if defined(LUA_COMPAT_MODULE)
+
+LUALIB_API void (luaL_pushmodule) (lua_State *L, const char *modname,
+                                   int sizehint);
+LUALIB_API void (luaL_openlib) (lua_State *L, const char *libname,
+                                const luaL_Reg *l, int nup);
+
+#define luaL_register(L,n,l)	(luaL_openlib(L,(n),(l),0))
+
+#endif
+
+
+/*
+** {==================================================================
+** "Abstraction Layer" for basic report of messages and errors
+** ===================================================================
+*/
+
+/* print a string */
+#if !defined(lua_writestring)
+#define lua_writestring(s,l)   fwrite((s), sizeof(char), (l), stdout)
+#endif
+
+/* print a newline and flush the output */
+#if !defined(lua_writeline)
+#define lua_writeline()        (lua_writestring("\n", 1), fflush(stdout))
+#endif
+
+/* print an error message */
+#if !defined(lua_writestringerror)
+#define lua_writestringerror(s,p) \
+        (fprintf(stderr, (s), (p)), fflush(stderr))
+#endif
+
+/* }================================================================== */
+
+
+/*
+** {============================================================
+** Compatibility with deprecated conversions
+** =============================================================
+*/
+#if defined(LUA_COMPAT_APIINTCASTS)
+
+#define luaL_checkunsigned(L,a)	((lua_Unsigned)luaL_checkinteger(L,a))
+#define luaL_optunsigned(L,a,d)	\
+	((lua_Unsigned)luaL_optinteger(L,a,(lua_Integer)(d)))
+
+#define luaL_checkint(L,n)	((int)luaL_checkinteger(L, (n)))
+#define luaL_optint(L,n,d)	((int)luaL_optinteger(L, (n), (d)))
+
+#define luaL_checklong(L,n)	((long)luaL_checkinteger(L, (n)))
+#define luaL_optlong(L,n,d)	((long)luaL_optinteger(L, (n), (d)))
+
+#endif
+/* }============================================================ */
+
+
+
+#endif
+
+
diff --git a/src/lbaselib.c b/src/lbaselib.c
new file mode 100644
index 0000000..d481c4e
--- /dev/null
+++ b/src/lbaselib.c
@@ -0,0 +1,498 @@
+/*
+** $Id: lbaselib.c,v 1.313 2016/04/11 19:18:40 roberto Exp $
+** Basic library
+** See Copyright Notice in lua.h
+*/
+
+#define lbaselib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+static int luaB_print (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  int i;
+  lua_getglobal(L, "tostring");
+  for (i=1; i<=n; i++) {
+    const char *s;
+    size_t l;
+    lua_pushvalue(L, -1);  /* function to be called */
+    lua_pushvalue(L, i);   /* value to print */
+    lua_call(L, 1, 1);
+    s = lua_tolstring(L, -1, &l);  /* get result */
+    if (s == NULL)
+      return luaL_error(L, "'tostring' must return a string to 'print'");
+    if (i>1) lua_writestring("\t", 1);
+    lua_writestring(s, l);
+    lua_pop(L, 1);  /* pop result */
+  }
+  lua_writeline();
+  return 0;
+}
+
+
+#define SPACECHARS	" \f\n\r\t\v"
+
+static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
+  lua_Unsigned n = 0;
+  int neg = 0;
+  s += strspn(s, SPACECHARS);  /* skip initial spaces */
+  if (*s == '-') { s++; neg = 1; }  /* handle signal */
+  else if (*s == '+') s++;
+  if (!isalnum((unsigned char)*s))  /* no digit? */
+    return NULL;
+  do {
+    int digit = (isdigit((unsigned char)*s)) ? *s - '0'
+                   : (toupper((unsigned char)*s) - 'A') + 10;
+    if (digit >= base) return NULL;  /* invalid numeral */
+    n = n * base + digit;
+    s++;
+  } while (isalnum((unsigned char)*s));
+  s += strspn(s, SPACECHARS);  /* skip trailing spaces */
+  *pn = (lua_Integer)((neg) ? (0u - n) : n);
+  return s;
+}
+
+
+static int luaB_tonumber (lua_State *L) {
+  if (lua_isnoneornil(L, 2)) {  /* standard conversion? */
+    luaL_checkany(L, 1);
+    if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */
+      lua_settop(L, 1);  /* yes; return it */
+      return 1;
+    }
+    else {
+      size_t l;
+      const char *s = lua_tolstring(L, 1, &l);
+      if (s != NULL && lua_stringtonumber(L, s) == l + 1)
+        return 1;  /* successful conversion to number */
+      /* else not a number */
+    }
+  }
+  else {
+    size_t l;
+    const char *s;
+    lua_Integer n = 0;  /* to avoid warnings */
+    lua_Integer base = luaL_checkinteger(L, 2);
+    luaL_checktype(L, 1, LUA_TSTRING);  /* no numbers as strings */
+    s = lua_tolstring(L, 1, &l);
+    luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
+    if (b_str2int(s, (int)base, &n) == s + l) {
+      lua_pushinteger(L, n);
+      return 1;
+    }  /* else not a number */
+  }  /* else not a number */
+  lua_pushnil(L);  /* not a number */
+  return 1;
+}
+
+
+static int luaB_error (lua_State *L) {
+  int level = (int)luaL_optinteger(L, 2, 1);
+  lua_settop(L, 1);
+  if (lua_type(L, 1) == LUA_TSTRING && level > 0) {
+    luaL_where(L, level);   /* add extra information */
+    lua_pushvalue(L, 1);
+    lua_concat(L, 2);
+  }
+  return lua_error(L);
+}
+
+
+static int luaB_getmetatable (lua_State *L) {
+  luaL_checkany(L, 1);
+  if (!lua_getmetatable(L, 1)) {
+    lua_pushnil(L);
+    return 1;  /* no metatable */
+  }
+  luaL_getmetafield(L, 1, "__metatable");
+  return 1;  /* returns either __metatable field (if present) or metatable */
+}
+
+
+static int luaB_setmetatable (lua_State *L) {
+  int t = lua_type(L, 2);
+  luaL_checktype(L, 1, LUA_TTABLE);
+  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
+                    "nil or table expected");
+  if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
+    return luaL_error(L, "cannot change a protected metatable");
+  lua_settop(L, 2);
+  lua_setmetatable(L, 1);
+  return 1;
+}
+
+
+static int luaB_rawequal (lua_State *L) {
+  luaL_checkany(L, 1);
+  luaL_checkany(L, 2);
+  lua_pushboolean(L, lua_rawequal(L, 1, 2));
+  return 1;
+}
+
+
+static int luaB_rawlen (lua_State *L) {
+  int t = lua_type(L, 1);
+  luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
+                   "table or string expected");
+  lua_pushinteger(L, lua_rawlen(L, 1));
+  return 1;
+}
+
+
+static int luaB_rawget (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  luaL_checkany(L, 2);
+  lua_settop(L, 2);
+  lua_rawget(L, 1);
+  return 1;
+}
+
+static int luaB_rawset (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  luaL_checkany(L, 2);
+  luaL_checkany(L, 3);
+  lua_settop(L, 3);
+  lua_rawset(L, 1);
+  return 1;
+}
+
+
+static int luaB_collectgarbage (lua_State *L) {
+  static const char *const opts[] = {"stop", "restart", "collect",
+    "count", "step", "setpause", "setstepmul",
+    "isrunning", NULL};
+  static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
+    LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
+    LUA_GCISRUNNING};
+  int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
+  int ex = (int)luaL_optinteger(L, 2, 0);
+  int res = lua_gc(L, o, ex);
+  switch (o) {
+    case LUA_GCCOUNT: {
+      int b = lua_gc(L, LUA_GCCOUNTB, 0);
+      lua_pushnumber(L, (lua_Number)res + ((lua_Number)b/1024));
+      return 1;
+    }
+    case LUA_GCSTEP: case LUA_GCISRUNNING: {
+      lua_pushboolean(L, res);
+      return 1;
+    }
+    default: {
+      lua_pushinteger(L, res);
+      return 1;
+    }
+  }
+}
+
+
+static int luaB_type (lua_State *L) {
+  int t = lua_type(L, 1);
+  luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
+  lua_pushstring(L, lua_typename(L, t));
+  return 1;
+}
+
+
+static int pairsmeta (lua_State *L, const char *method, int iszero,
+                      lua_CFunction iter) {
+  if (luaL_getmetafield(L, 1, method) == LUA_TNIL) {  /* no metamethod? */
+    luaL_checktype(L, 1, LUA_TTABLE);  /* argument must be a table */
+    lua_pushcfunction(L, iter);  /* will return generator, */
+    lua_pushvalue(L, 1);  /* state, */
+    if (iszero) lua_pushinteger(L, 0);  /* and initial value */
+    else lua_pushnil(L);
+  }
+  else {
+    lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
+    lua_call(L, 1, 3);  /* get 3 values from metamethod */
+  }
+  return 3;
+}
+
+
+static int luaB_next (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
+  if (lua_next(L, 1))
+    return 2;
+  else {
+    lua_pushnil(L);
+    return 1;
+  }
+}
+
+
+static int luaB_pairs (lua_State *L) {
+  return pairsmeta(L, "__pairs", 0, luaB_next);
+}
+
+
+/*
+** Traversal function for 'ipairs'
+*/
+static int ipairsaux (lua_State *L) {
+  lua_Integer i = luaL_checkinteger(L, 2) + 1;
+  lua_pushinteger(L, i);
+  return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
+}
+
+
+/*
+** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
+** (The given "table" may not be a table.)
+*/
+static int luaB_ipairs (lua_State *L) {
+#if defined(LUA_COMPAT_IPAIRS)
+  return pairsmeta(L, "__ipairs", 1, ipairsaux);
+#else
+  luaL_checkany(L, 1);
+  lua_pushcfunction(L, ipairsaux);  /* iteration function */
+  lua_pushvalue(L, 1);  /* state */
+  lua_pushinteger(L, 0);  /* initial value */
+  return 3;
+#endif
+}
+
+
+static int load_aux (lua_State *L, int status, int envidx) {
+  if (status == LUA_OK) {
+    if (envidx != 0) {  /* 'env' parameter? */
+      lua_pushvalue(L, envidx);  /* environment for loaded function */
+      if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
+        lua_pop(L, 1);  /* remove 'env' if not used by previous call */
+    }
+    return 1;
+  }
+  else {  /* error (message is on top of the stack) */
+    lua_pushnil(L);
+    lua_insert(L, -2);  /* put before error message */
+    return 2;  /* return nil plus error message */
+  }
+}
+
+
+static int luaB_loadfile (lua_State *L) {
+  const char *fname = luaL_optstring(L, 1, NULL);
+  const char *mode = luaL_optstring(L, 2, NULL);
+  int env = (!lua_isnone(L, 3) ? 3 : 0);  /* 'env' index or 0 if no 'env' */
+  int status = luaL_loadfilex(L, fname, mode);
+  return load_aux(L, status, env);
+}
+
+
+/*
+** {======================================================
+** Generic Read function
+** =======================================================
+*/
+
+
+/*
+** reserved slot, above all arguments, to hold a copy of the returned
+** string to avoid it being collected while parsed. 'load' has four
+** optional arguments (chunk, source name, mode, and environment).
+*/
+#define RESERVEDSLOT	5
+
+
+/*
+** Reader for generic 'load' function: 'lua_load' uses the
+** stack for internal stuff, so the reader cannot change the
+** stack top. Instead, it keeps its resulting string in a
+** reserved slot inside the stack.
+*/
+static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
+  (void)(ud);  /* not used */
+  luaL_checkstack(L, 2, "too many nested functions");
+  lua_pushvalue(L, 1);  /* get function */
+  lua_call(L, 0, 1);  /* call it */
+  if (lua_isnil(L, -1)) {
+    lua_pop(L, 1);  /* pop result */
+    *size = 0;
+    return NULL;
+  }
+  else if (!lua_isstring(L, -1))
+    luaL_error(L, "reader function must return a string");
+  lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
+  return lua_tolstring(L, RESERVEDSLOT, size);
+}
+
+
+static int luaB_load (lua_State *L) {
+  int status;
+  size_t l;
+  const char *s = lua_tolstring(L, 1, &l);
+  const char *mode = luaL_optstring(L, 3, "bt");
+  int env = (!lua_isnone(L, 4) ? 4 : 0);  /* 'env' index or 0 if no 'env' */
+  if (s != NULL) {  /* loading a string? */
+    const char *chunkname = luaL_optstring(L, 2, s);
+    status = luaL_loadbufferx(L, s, l, chunkname, mode);
+  }
+  else {  /* loading from a reader function */
+    const char *chunkname = luaL_optstring(L, 2, "=(load)");
+    luaL_checktype(L, 1, LUA_TFUNCTION);
+    lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
+    status = lua_load(L, generic_reader, NULL, chunkname, mode);
+  }
+  return load_aux(L, status, env);
+}
+
+/* }====================================================== */
+
+
+static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
+  (void)d1;  (void)d2;  /* only to match 'lua_Kfunction' prototype */
+  return lua_gettop(L) - 1;
+}
+
+
+static int luaB_dofile (lua_State *L) {
+  const char *fname = luaL_optstring(L, 1, NULL);
+  lua_settop(L, 1);
+  if (luaL_loadfile(L, fname) != LUA_OK)
+    return lua_error(L);
+  lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
+  return dofilecont(L, 0, 0);
+}
+
+
+static int luaB_assert (lua_State *L) {
+  if (lua_toboolean(L, 1))  /* condition is true? */
+    return lua_gettop(L);  /* return all arguments */
+  else {  /* error */
+    luaL_checkany(L, 1);  /* there must be a condition */
+    lua_remove(L, 1);  /* remove it */
+    lua_pushliteral(L, "assertion failed!");  /* default message */
+    lua_settop(L, 1);  /* leave only message (default if no other one) */
+    return luaB_error(L);  /* call 'error' */
+  }
+}
+
+
+static int luaB_select (lua_State *L) {
+  int n = lua_gettop(L);
+  if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
+    lua_pushinteger(L, n-1);
+    return 1;
+  }
+  else {
+    lua_Integer i = luaL_checkinteger(L, 1);
+    if (i < 0) i = n + i;
+    else if (i > n) i = n;
+    luaL_argcheck(L, 1 <= i, 1, "index out of range");
+    return n - (int)i;
+  }
+}
+
+
+/*
+** Continuation function for 'pcall' and 'xpcall'. Both functions
+** already pushed a 'true' before doing the call, so in case of success
+** 'finishpcall' only has to return everything in the stack minus
+** 'extra' values (where 'extra' is exactly the number of items to be
+** ignored).
+*/
+static int finishpcall (lua_State *L, int status, lua_KContext extra) {
+  if (status != LUA_OK && status != LUA_YIELD) {  /* error? */
+    lua_pushboolean(L, 0);  /* first result (false) */
+    lua_pushvalue(L, -2);  /* error message */
+    return 2;  /* return false, msg */
+  }
+  else
+    return lua_gettop(L) - (int)extra;  /* return all results */
+}
+
+
+static int luaB_pcall (lua_State *L) {
+  int status;
+  luaL_checkany(L, 1);
+  lua_pushboolean(L, 1);  /* first result if no errors */
+  lua_insert(L, 1);  /* put it in place */
+  status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
+  return finishpcall(L, status, 0);
+}
+
+
+/*
+** Do a protected call with error handling. After 'lua_rotate', the
+** stack will have <f, err, true, f, [args...]>; so, the function passes
+** 2 to 'finishpcall' to skip the 2 first values when returning results.
+*/
+static int luaB_xpcall (lua_State *L) {
+  int status;
+  int n = lua_gettop(L);
+  luaL_checktype(L, 2, LUA_TFUNCTION);  /* check error function */
+  lua_pushboolean(L, 1);  /* first result */
+  lua_pushvalue(L, 1);  /* function */
+  lua_rotate(L, 3, 2);  /* move them below function's arguments */
+  status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
+  return finishpcall(L, status, 2);
+}
+
+
+static int luaB_tostring (lua_State *L) {
+  luaL_checkany(L, 1);
+  luaL_tolstring(L, 1, NULL);
+  return 1;
+}
+
+
+static const luaL_Reg base_funcs[] = {
+  {"assert", luaB_assert},
+  {"collectgarbage", luaB_collectgarbage},
+  {"dofile", luaB_dofile},
+  {"error", luaB_error},
+  {"getmetatable", luaB_getmetatable},
+  {"ipairs", luaB_ipairs},
+  {"loadfile", luaB_loadfile},
+  {"load", luaB_load},
+#if defined(LUA_COMPAT_LOADSTRING)
+  {"loadstring", luaB_load},
+#endif
+  {"next", luaB_next},
+  {"pairs", luaB_pairs},
+  {"pcall", luaB_pcall},
+  {"print", luaB_print},
+  {"rawequal", luaB_rawequal},
+  {"rawlen", luaB_rawlen},
+  {"rawget", luaB_rawget},
+  {"rawset", luaB_rawset},
+  {"select", luaB_select},
+  {"setmetatable", luaB_setmetatable},
+  {"tonumber", luaB_tonumber},
+  {"tostring", luaB_tostring},
+  {"type", luaB_type},
+  {"xpcall", luaB_xpcall},
+  /* placeholders */
+  {"_G", NULL},
+  {"_VERSION", NULL},
+  {NULL, NULL}
+};
+
+
+LUAMOD_API int luaopen_base (lua_State *L) {
+  /* open lib into global table */
+  lua_pushglobaltable(L);
+  luaL_setfuncs(L, base_funcs, 0);
+  /* set global _G */
+  lua_pushvalue(L, -1);
+  lua_setfield(L, -2, "_G");
+  /* set global _VERSION */
+  lua_pushliteral(L, LUA_VERSION);
+  lua_setfield(L, -2, "_VERSION");
+  return 1;
+}
+
diff --git a/src/lbitlib.c b/src/lbitlib.c
new file mode 100644
index 0000000..1cb1d5b
--- /dev/null
+++ b/src/lbitlib.c
@@ -0,0 +1,233 @@
+/*
+** $Id: lbitlib.c,v 1.30 2015/11/11 19:08:09 roberto Exp $
+** Standard library for bitwise operations
+** See Copyright Notice in lua.h
+*/
+
+#define lbitlib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+#if defined(LUA_COMPAT_BITLIB)		/* { */
+
+
+#define pushunsigned(L,n)	lua_pushinteger(L, (lua_Integer)(n))
+#define checkunsigned(L,i)	((lua_Unsigned)luaL_checkinteger(L,i))
+
+
+/* number of bits to consider in a number */
+#if !defined(LUA_NBITS)
+#define LUA_NBITS	32
+#endif
+
+
+/*
+** a lua_Unsigned with its first LUA_NBITS bits equal to 1. (Shift must
+** be made in two parts to avoid problems when LUA_NBITS is equal to the
+** number of bits in a lua_Unsigned.)
+*/
+#define ALLONES		(~(((~(lua_Unsigned)0) << (LUA_NBITS - 1)) << 1))
+
+
+/* macro to trim extra bits */
+#define trim(x)		((x) & ALLONES)
+
+
+/* builds a number with 'n' ones (1 <= n <= LUA_NBITS) */
+#define mask(n)		(~((ALLONES << 1) << ((n) - 1)))
+
+
+
+static lua_Unsigned andaux (lua_State *L) {
+  int i, n = lua_gettop(L);
+  lua_Unsigned r = ~(lua_Unsigned)0;
+  for (i = 1; i <= n; i++)
+    r &= checkunsigned(L, i);
+  return trim(r);
+}
+
+
+static int b_and (lua_State *L) {
+  lua_Unsigned r = andaux(L);
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static int b_test (lua_State *L) {
+  lua_Unsigned r = andaux(L);
+  lua_pushboolean(L, r != 0);
+  return 1;
+}
+
+
+static int b_or (lua_State *L) {
+  int i, n = lua_gettop(L);
+  lua_Unsigned r = 0;
+  for (i = 1; i <= n; i++)
+    r |= checkunsigned(L, i);
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_xor (lua_State *L) {
+  int i, n = lua_gettop(L);
+  lua_Unsigned r = 0;
+  for (i = 1; i <= n; i++)
+    r ^= checkunsigned(L, i);
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_not (lua_State *L) {
+  lua_Unsigned r = ~checkunsigned(L, 1);
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_shift (lua_State *L, lua_Unsigned r, lua_Integer i) {
+  if (i < 0) {  /* shift right? */
+    i = -i;
+    r = trim(r);
+    if (i >= LUA_NBITS) r = 0;
+    else r >>= i;
+  }
+  else {  /* shift left */
+    if (i >= LUA_NBITS) r = 0;
+    else r <<= i;
+    r = trim(r);
+  }
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static int b_lshift (lua_State *L) {
+  return b_shift(L, checkunsigned(L, 1), luaL_checkinteger(L, 2));
+}
+
+
+static int b_rshift (lua_State *L) {
+  return b_shift(L, checkunsigned(L, 1), -luaL_checkinteger(L, 2));
+}
+
+
+static int b_arshift (lua_State *L) {
+  lua_Unsigned r = checkunsigned(L, 1);
+  lua_Integer i = luaL_checkinteger(L, 2);
+  if (i < 0 || !(r & ((lua_Unsigned)1 << (LUA_NBITS - 1))))
+    return b_shift(L, r, -i);
+  else {  /* arithmetic shift for 'negative' number */
+    if (i >= LUA_NBITS) r = ALLONES;
+    else
+      r = trim((r >> i) | ~(trim(~(lua_Unsigned)0) >> i));  /* add signal bit */
+    pushunsigned(L, r);
+    return 1;
+  }
+}
+
+
+static int b_rot (lua_State *L, lua_Integer d) {
+  lua_Unsigned r = checkunsigned(L, 1);
+  int i = d & (LUA_NBITS - 1);  /* i = d % NBITS */
+  r = trim(r);
+  if (i != 0)  /* avoid undefined shift of LUA_NBITS when i == 0 */
+    r = (r << i) | (r >> (LUA_NBITS - i));
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_lrot (lua_State *L) {
+  return b_rot(L, luaL_checkinteger(L, 2));
+}
+
+
+static int b_rrot (lua_State *L) {
+  return b_rot(L, -luaL_checkinteger(L, 2));
+}
+
+
+/*
+** get field and width arguments for field-manipulation functions,
+** checking whether they are valid.
+** ('luaL_error' called without 'return' to avoid later warnings about
+** 'width' being used uninitialized.)
+*/
+static int fieldargs (lua_State *L, int farg, int *width) {
+  lua_Integer f = luaL_checkinteger(L, farg);
+  lua_Integer w = luaL_optinteger(L, farg + 1, 1);
+  luaL_argcheck(L, 0 <= f, farg, "field cannot be negative");
+  luaL_argcheck(L, 0 < w, farg + 1, "width must be positive");
+  if (f + w > LUA_NBITS)
+    luaL_error(L, "trying to access non-existent bits");
+  *width = (int)w;
+  return (int)f;
+}
+
+
+static int b_extract (lua_State *L) {
+  int w;
+  lua_Unsigned r = trim(checkunsigned(L, 1));
+  int f = fieldargs(L, 2, &w);
+  r = (r >> f) & mask(w);
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static int b_replace (lua_State *L) {
+  int w;
+  lua_Unsigned r = trim(checkunsigned(L, 1));
+  lua_Unsigned v = trim(checkunsigned(L, 2));
+  int f = fieldargs(L, 3, &w);
+  lua_Unsigned m = mask(w);
+  r = (r & ~(m << f)) | ((v & m) << f);
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static const luaL_Reg bitlib[] = {
+  {"arshift", b_arshift},
+  {"band", b_and},
+  {"bnot", b_not},
+  {"bor", b_or},
+  {"bxor", b_xor},
+  {"btest", b_test},
+  {"extract", b_extract},
+  {"lrotate", b_lrot},
+  {"lshift", b_lshift},
+  {"replace", b_replace},
+  {"rrotate", b_rrot},
+  {"rshift", b_rshift},
+  {NULL, NULL}
+};
+
+
+
+LUAMOD_API int luaopen_bit32 (lua_State *L) {
+  luaL_newlib(L, bitlib);
+  return 1;
+}
+
+
+#else					/* }{ */
+
+
+LUAMOD_API int luaopen_bit32 (lua_State *L) {
+  return luaL_error(L, "library 'bit32' has been deprecated");
+}
+
+#endif					/* } */
diff --git a/src/lcode.c b/src/lcode.c
new file mode 100644
index 0000000..2cd0dd2
--- /dev/null
+++ b/src/lcode.c
@@ -0,0 +1,1199 @@
+/*
+** $Id: lcode.c,v 2.109 2016/05/13 19:09:21 roberto Exp $
+** Code generator for Lua
+** See Copyright Notice in lua.h
+*/
+
+#define lcode_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <math.h>
+#include <stdlib.h>
+
+#include "lua.h"
+
+#include "lcode.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
+#include "llex.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lparser.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "lvm.h"
+
+
+/* Maximum number of registers in a Lua function (must fit in 8 bits) */
+#define MAXREGS		255
+
+
+#define hasjumps(e)	((e)->t != (e)->f)
+
+
+/*
+** If expression is a numeric constant, fills 'v' with its value
+** and returns 1. Otherwise, returns 0.
+*/
+static int tonumeral(expdesc *e, TValue *v) {
+  if (hasjumps(e))
+    return 0;  /* not a numeral */
+  switch (e->k) {
+    case VKINT:
+      if (v) setivalue(v, e->u.ival);
+      return 1;
+    case VKFLT:
+      if (v) setfltvalue(v, e->u.nval);
+      return 1;
+    default: return 0;
+  }
+}
+
+
+/*
+** Create a OP_LOADNIL instruction, but try to optimize: if the previous
+** instruction is also OP_LOADNIL and ranges are compatible, adjust
+** range of previous instruction instead of emitting a new one. (For
+** instance, 'local a; local b' will generate a single opcode.)
+*/
+void luaK_nil (FuncState *fs, int from, int n) {
+  Instruction *previous;
+  int l = from + n - 1;  /* last register to set nil */
+  if (fs->pc > fs->lasttarget) {  /* no jumps to current position? */
+    previous = &fs->f->code[fs->pc-1];
+    if (GET_OPCODE(*previous) == OP_LOADNIL) {  /* previous is LOADNIL? */
+      int pfrom = GETARG_A(*previous);  /* get previous range */
+      int pl = pfrom + GETARG_B(*previous);
+      if ((pfrom <= from && from <= pl + 1) ||
+          (from <= pfrom && pfrom <= l + 1)) {  /* can connect both? */
+        if (pfrom < from) from = pfrom;  /* from = min(from, pfrom) */
+        if (pl > l) l = pl;  /* l = max(l, pl) */
+        SETARG_A(*previous, from);
+        SETARG_B(*previous, l - from);
+        return;
+      }
+    }  /* else go through */
+  }
+  luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0);  /* else no optimization */
+}
+
+
+/*
+** Gets the destination address of a jump instruction. Used to traverse
+** a list of jumps.
+*/ 
+static int getjump (FuncState *fs, int pc) {
+  int offset = GETARG_sBx(fs->f->code[pc]);
+  if (offset == NO_JUMP)  /* point to itself represents end of list */
+    return NO_JUMP;  /* end of list */
+  else
+    return (pc+1)+offset;  /* turn offset into absolute position */
+}
+
+
+/*
+** Fix jump instruction at position 'pc' to jump to 'dest'.
+** (Jump addresses are relative in Lua)
+*/
+static void fixjump (FuncState *fs, int pc, int dest) {
+  Instruction *jmp = &fs->f->code[pc];
+  int offset = dest - (pc + 1);
+  lua_assert(dest != NO_JUMP);
+  if (abs(offset) > MAXARG_sBx)
+    luaX_syntaxerror(fs->ls, "control structure too long");
+  SETARG_sBx(*jmp, offset);
+}
+
+
+/*
+** Concatenate jump-list 'l2' into jump-list 'l1'
+*/
+void luaK_concat (FuncState *fs, int *l1, int l2) {
+  if (l2 == NO_JUMP) return;  /* nothing to concatenate? */
+  else if (*l1 == NO_JUMP)  /* no original list? */
+    *l1 = l2;  /* 'l1' points to 'l2' */
+  else {
+    int list = *l1;
+    int next;
+    while ((next = getjump(fs, list)) != NO_JUMP)  /* find last element */
+      list = next;
+    fixjump(fs, list, l2);  /* last element links to 'l2' */
+  }
+}
+
+
+/*
+** Create a jump instruction and return its position, so its destination
+** can be fixed later (with 'fixjump'). If there are jumps to
+** this position (kept in 'jpc'), link them all together so that
+** 'patchlistaux' will fix all them directly to the final destination.
+*/
+int luaK_jump (FuncState *fs) {
+  int jpc = fs->jpc;  /* save list of jumps to here */
+  int j;
+  fs->jpc = NO_JUMP;  /* no more jumps to here */
+  j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
+  luaK_concat(fs, &j, jpc);  /* keep them on hold */
+  return j;
+}
+
+
+/*
+** Code a 'return' instruction
+*/
+void luaK_ret (FuncState *fs, int first, int nret) {
+  luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
+}
+
+
+/*
+** Code a "conditional jump", that is, a test or comparison opcode
+** followed by a jump. Return jump position.
+*/
+static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
+  luaK_codeABC(fs, op, A, B, C);
+  return luaK_jump(fs);
+}
+
+
+/*
+** returns current 'pc' and marks it as a jump target (to avoid wrong
+** optimizations with consecutive instructions not in the same basic block).
+*/
+int luaK_getlabel (FuncState *fs) {
+  fs->lasttarget = fs->pc;
+  return fs->pc;
+}
+
+
+/*
+** Returns the position of the instruction "controlling" a given
+** jump (that is, its condition), or the jump itself if it is
+** unconditional.
+*/
+static Instruction *getjumpcontrol (FuncState *fs, int pc) {
+  Instruction *pi = &fs->f->code[pc];
+  if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))
+    return pi-1;
+  else
+    return pi;
+}
+
+
+/*
+** Patch destination register for a TESTSET instruction.
+** If instruction in position 'node' is not a TESTSET, return 0 ("fails").
+** Otherwise, if 'reg' is not 'NO_REG', set it as the destination
+** register. Otherwise, change instruction to a simple 'TEST' (produces
+** no register value)
+*/
+static int patchtestreg (FuncState *fs, int node, int reg) {
+  Instruction *i = getjumpcontrol(fs, node);
+  if (GET_OPCODE(*i) != OP_TESTSET)
+    return 0;  /* cannot patch other instructions */
+  if (reg != NO_REG && reg != GETARG_B(*i))
+    SETARG_A(*i, reg);
+  else {
+     /* no register to put value or register already has the value;
+        change instruction to simple test */
+    *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
+  }
+  return 1;
+}
+
+
+/*
+** Traverse a list of tests ensuring no one produces a value
+*/
+static void removevalues (FuncState *fs, int list) {
+  for (; list != NO_JUMP; list = getjump(fs, list))
+      patchtestreg(fs, list, NO_REG);
+}
+
+
+/*
+** Traverse a list of tests, patching their destination address and
+** registers: tests producing values jump to 'vtarget' (and put their
+** values in 'reg'), other tests jump to 'dtarget'.
+*/
+static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
+                          int dtarget) {
+  while (list != NO_JUMP) {
+    int next = getjump(fs, list);
+    if (patchtestreg(fs, list, reg))
+      fixjump(fs, list, vtarget);
+    else
+      fixjump(fs, list, dtarget);  /* jump to default target */
+    list = next;
+  }
+}
+
+
+/*
+** Ensure all pending jumps to current position are fixed (jumping
+** to current position with no values) and reset list of pending
+** jumps
+*/
+static void dischargejpc (FuncState *fs) {
+  patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
+  fs->jpc = NO_JUMP;
+}
+
+
+/*
+** Add elements in 'list' to list of pending jumps to "here"
+** (current position)
+*/
+void luaK_patchtohere (FuncState *fs, int list) {
+  luaK_getlabel(fs);  /* mark "here" as a jump target */
+  luaK_concat(fs, &fs->jpc, list);
+}
+
+
+/*
+** Path all jumps in 'list' to jump to 'target'.
+** (The assert means that we cannot fix a jump to a forward address
+** because we only know addresses once code is generated.)
+*/
+void luaK_patchlist (FuncState *fs, int list, int target) {
+  if (target == fs->pc)  /* 'target' is current position? */
+    luaK_patchtohere(fs, list);  /* add list to pending jumps */
+  else {
+    lua_assert(target < fs->pc);
+    patchlistaux(fs, list, target, NO_REG, target);
+  }
+}
+
+
+/*
+** Path all jumps in 'list' to close upvalues up to given 'level'
+** (The assertion checks that jumps either were closing nothing
+** or were closing higher levels, from inner blocks.)
+*/
+void luaK_patchclose (FuncState *fs, int list, int level) {
+  level++;  /* argument is +1 to reserve 0 as non-op */
+  for (; list != NO_JUMP; list = getjump(fs, list)) {
+    lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP &&
+                (GETARG_A(fs->f->code[list]) == 0 ||
+                 GETARG_A(fs->f->code[list]) >= level));
+    SETARG_A(fs->f->code[list], level);
+  }
+}
+
+
+/*
+** Emit instruction 'i', checking for array sizes and saving also its
+** line information. Return 'i' position.
+*/
+static int luaK_code (FuncState *fs, Instruction i) {
+  Proto *f = fs->f;
+  dischargejpc(fs);  /* 'pc' will change */
+  /* put new instruction in code array */
+  luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction,
+                  MAX_INT, "opcodes");
+  f->code[fs->pc] = i;
+  /* save corresponding line information */
+  luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
+                  MAX_INT, "opcodes");
+  f->lineinfo[fs->pc] = fs->ls->lastline;
+  return fs->pc++;
+}
+
+
+/*
+** Format and emit an 'iABC' instruction. (Assertions check consistency
+** of parameters versus opcode.)
+*/
+int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
+  lua_assert(getOpMode(o) == iABC);
+  lua_assert(getBMode(o) != OpArgN || b == 0);
+  lua_assert(getCMode(o) != OpArgN || c == 0);
+  lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C);
+  return luaK_code(fs, CREATE_ABC(o, a, b, c));
+}
+
+
+/*
+** Format and emit an 'iABx' instruction.
+*/
+int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
+  lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
+  lua_assert(getCMode(o) == OpArgN);
+  lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx);
+  return luaK_code(fs, CREATE_ABx(o, a, bc));
+}
+
+
+/*
+** Emit an "extra argument" instruction (format 'iAx')
+*/
+static int codeextraarg (FuncState *fs, int a) {
+  lua_assert(a <= MAXARG_Ax);
+  return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a));
+}
+
+
+/*
+** Emit a "load constant" instruction, using either 'OP_LOADK'
+** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX'
+** instruction with "extra argument".
+*/
+int luaK_codek (FuncState *fs, int reg, int k) {
+  if (k <= MAXARG_Bx)
+    return luaK_codeABx(fs, OP_LOADK, reg, k);
+  else {
+    int p = luaK_codeABx(fs, OP_LOADKX, reg, 0);
+    codeextraarg(fs, k);
+    return p;
+  }
+}
+
+
+/*
+** Check register-stack level, keeping track of its maximum size
+** in field 'maxstacksize'
+*/
+void luaK_checkstack (FuncState *fs, int n) {
+  int newstack = fs->freereg + n;
+  if (newstack > fs->f->maxstacksize) {
+    if (newstack >= MAXREGS)
+      luaX_syntaxerror(fs->ls,
+        "function or expression needs too many registers");
+    fs->f->maxstacksize = cast_byte(newstack);
+  }
+}
+
+
+/*
+** Reserve 'n' registers in register stack
+*/
+void luaK_reserveregs (FuncState *fs, int n) {
+  luaK_checkstack(fs, n);
+  fs->freereg += n;
+}
+
+
+/*
+** Free register 'reg', if it is neither a constant index nor
+** a local variable.
+)
+*/
+static void freereg (FuncState *fs, int reg) {
+  if (!ISK(reg) && reg >= fs->nactvar) {
+    fs->freereg--;
+    lua_assert(reg == fs->freereg);
+  }
+}
+
+
+/*
+** Free register used by expression 'e' (if any)
+*/
+static void freeexp (FuncState *fs, expdesc *e) {
+  if (e->k == VNONRELOC)
+    freereg(fs, e->u.info);
+}
+
+
+/*
+** Free registers used by expressions 'e1' and 'e2' (if any) in proper
+** order.
+*/
+static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) {
+  int r1 = (e1->k == VNONRELOC) ? e1->u.info : -1;
+  int r2 = (e2->k == VNONRELOC) ? e2->u.info : -1;
+  if (r1 > r2) {
+    freereg(fs, r1);
+    freereg(fs, r2);
+  }
+  else {
+    freereg(fs, r2);
+    freereg(fs, r1);
+  }
+}
+
+
+/*
+** Add constant 'v' to prototype's list of constants (field 'k').
+** Use scanner's table to cache position of constants in constant list
+** and try to reuse constants. Because some values should not be used
+** as keys (nil cannot be a key, integer keys can collapse with float
+** keys), the caller must provide a useful 'key' for indexing the cache.
+*/
+static int addk (FuncState *fs, TValue *key, TValue *v) {
+  lua_State *L = fs->ls->L;
+  Proto *f = fs->f;
+  TValue *idx = luaH_set(L, fs->ls->h, key);  /* index scanner table */
+  int k, oldsize;
+  if (ttisinteger(idx)) {  /* is there an index there? */
+    k = cast_int(ivalue(idx));
+    /* correct value? (warning: must distinguish floats from integers!) */
+    if (k < fs->nk && ttype(&f->k[k]) == ttype(v) &&
+                      luaV_rawequalobj(&f->k[k], v))
+      return k;  /* reuse index */
+  }
+  /* constant not found; create a new entry */
+  oldsize = f->sizek;
+  k = fs->nk;
+  /* numerical value does not need GC barrier;
+     table has no metatable, so it does not need to invalidate cache */
+  setivalue(idx, k);
+  luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants");
+  while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
+  setobj(L, &f->k[k], v);
+  fs->nk++;
+  luaC_barrier(L, f, v);
+  return k;
+}
+
+
+/*
+** Add a string to list of constants and return its index.
+*/
+int luaK_stringK (FuncState *fs, TString *s) {
+  TValue o;
+  setsvalue(fs->ls->L, &o, s);
+  return addk(fs, &o, &o);  /* use string itself as key */
+}
+
+
+/*
+** Add an integer to list of constants and return its index.
+** Integers use userdata as keys to avoid collision with floats with
+** same value; conversion to 'void*' is used only for hashing, so there
+** are no "precision" problems.
+*/
+int luaK_intK (FuncState *fs, lua_Integer n) {
+  TValue k, o;
+  setpvalue(&k, cast(void*, cast(size_t, n)));
+  setivalue(&o, n);
+  return addk(fs, &k, &o);
+}
+
+/*
+** Add a float to list of constants and return its index.
+*/
+static int luaK_numberK (FuncState *fs, lua_Number r) {
+  TValue o;
+  setfltvalue(&o, r);
+  return addk(fs, &o, &o);  /* use number itself as key */
+}
+
+
+/*
+** Add a boolean to list of constants and return its index.
+*/
+static int boolK (FuncState *fs, int b) {
+  TValue o;
+  setbvalue(&o, b);
+  return addk(fs, &o, &o);  /* use boolean itself as key */
+}
+
+
+/*
+** Add nil to list of constants and return its index.
+*/
+static int nilK (FuncState *fs) {
+  TValue k, v;
+  setnilvalue(&v);
+  /* cannot use nil as key; instead use table itself to represent nil */
+  sethvalue(fs->ls->L, &k, fs->ls->h);
+  return addk(fs, &k, &v);
+}
+
+
+/*
+** Fix an expression to return the number of results 'nresults'.
+** Either 'e' is a multi-ret expression (function call or vararg)
+** or 'nresults' is LUA_MULTRET (as any expression can satisfy that).
+*/
+void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
+  if (e->k == VCALL) {  /* expression is an open function call? */
+    SETARG_C(getinstruction(fs, e), nresults + 1);
+  }
+  else if (e->k == VVARARG) {
+    Instruction *pc = &getinstruction(fs, e);
+    SETARG_B(*pc, nresults + 1);
+    SETARG_A(*pc, fs->freereg);
+    luaK_reserveregs(fs, 1);
+  }
+  else lua_assert(nresults == LUA_MULTRET);
+}
+
+
+/*
+** Fix an expression to return one result.
+** If expression is not a multi-ret expression (function call or
+** vararg), it already returns one result, so nothing needs to be done.
+** Function calls become VNONRELOC expressions (as its result comes
+** fixed in the base register of the call), while vararg expressions
+** become VRELOCABLE (as OP_VARARG puts its results where it wants).
+** (Calls are created returning one result, so that does not need
+** to be fixed.)
+*/
+void luaK_setoneret (FuncState *fs, expdesc *e) {
+  if (e->k == VCALL) {  /* expression is an open function call? */
+    /* already returns 1 value */
+    lua_assert(GETARG_C(getinstruction(fs, e)) == 2);
+    e->k = VNONRELOC;  /* result has fixed position */
+    e->u.info = GETARG_A(getinstruction(fs, e));
+  }
+  else if (e->k == VVARARG) {
+    SETARG_B(getinstruction(fs, e), 2);
+    e->k = VRELOCABLE;  /* can relocate its simple result */
+  }
+}
+
+
+/*
+** Ensure that expression 'e' is not a variable.
+*/
+void luaK_dischargevars (FuncState *fs, expdesc *e) {
+  switch (e->k) {
+    case VLOCAL: {  /* already in a register */
+      e->k = VNONRELOC;  /* becomes a non-relocatable value */
+      break;
+    }
+    case VUPVAL: {  /* move value to some (pending) register */
+      e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);
+      e->k = VRELOCABLE;
+      break;
+    }
+    case VINDEXED: {
+      OpCode op;
+      freereg(fs, e->u.ind.idx);
+      if (e->u.ind.vt == VLOCAL) {  /* is 't' in a register? */
+        freereg(fs, e->u.ind.t);
+        op = OP_GETTABLE;
+      }
+      else {
+        lua_assert(e->u.ind.vt == VUPVAL);
+        op = OP_GETTABUP;  /* 't' is in an upvalue */
+      }
+      e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx);
+      e->k = VRELOCABLE;
+      break;
+    }
+    case VVARARG: case VCALL: {
+      luaK_setoneret(fs, e);
+      break;
+    }
+    default: break;  /* there is one value available (somewhere) */
+  }
+}
+
+
+/*
+** Ensures expression value is in register 'reg' (and therefore
+** 'e' will become a non-relocatable expression).
+*/
+static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VNIL: {
+      luaK_nil(fs, reg, 1);
+      break;
+    }
+    case VFALSE: case VTRUE: {
+      luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
+      break;
+    }
+    case VK: {
+      luaK_codek(fs, reg, e->u.info);
+      break;
+    }
+    case VKFLT: {
+      luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval));
+      break;
+    }
+    case VKINT: {
+      luaK_codek(fs, reg, luaK_intK(fs, e->u.ival));
+      break;
+    }
+    case VRELOCABLE: {
+      Instruction *pc = &getinstruction(fs, e);
+      SETARG_A(*pc, reg);  /* instruction will put result in 'reg' */
+      break;
+    }
+    case VNONRELOC: {
+      if (reg != e->u.info)
+        luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0);
+      break;
+    }
+    default: {
+      lua_assert(e->k == VJMP);
+      return;  /* nothing to do... */
+    }
+  }
+  e->u.info = reg;
+  e->k = VNONRELOC;
+}
+
+
+/*
+** Ensures expression value is in any register.
+*/
+static void discharge2anyreg (FuncState *fs, expdesc *e) {
+  if (e->k != VNONRELOC) {  /* no fixed register yet? */
+    luaK_reserveregs(fs, 1);  /* get a register */
+    discharge2reg(fs, e, fs->freereg-1);  /* put value there */
+  }
+}
+
+
+static int code_loadbool (FuncState *fs, int A, int b, int jump) {
+  luaK_getlabel(fs);  /* those instructions may be jump targets */
+  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
+}
+
+
+/*
+** check whether list has any jump that do not produce a value
+** or produce an inverted value
+*/
+static int need_value (FuncState *fs, int list) {
+  for (; list != NO_JUMP; list = getjump(fs, list)) {
+    Instruction i = *getjumpcontrol(fs, list);
+    if (GET_OPCODE(i) != OP_TESTSET) return 1;
+  }
+  return 0;  /* not found */
+}
+
+
+/*
+** Ensures final expression result (including results from its jump
+** lists) is in register 'reg'.
+** If expression has jumps, need to patch these jumps either to
+** its final position or to "load" instructions (for those tests
+** that do not produce values).
+*/
+static void exp2reg (FuncState *fs, expdesc *e, int reg) {
+  discharge2reg(fs, e, reg);
+  if (e->k == VJMP)  /* expression itself is a test? */
+    luaK_concat(fs, &e->t, e->u.info);  /* put this jump in 't' list */
+  if (hasjumps(e)) {
+    int final;  /* position after whole expression */
+    int p_f = NO_JUMP;  /* position of an eventual LOAD false */
+    int p_t = NO_JUMP;  /* position of an eventual LOAD true */
+    if (need_value(fs, e->t) || need_value(fs, e->f)) {
+      int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
+      p_f = code_loadbool(fs, reg, 0, 1);
+      p_t = code_loadbool(fs, reg, 1, 0);
+      luaK_patchtohere(fs, fj);
+    }
+    final = luaK_getlabel(fs);
+    patchlistaux(fs, e->f, final, reg, p_f);
+    patchlistaux(fs, e->t, final, reg, p_t);
+  }
+  e->f = e->t = NO_JUMP;
+  e->u.info = reg;
+  e->k = VNONRELOC;
+}
+
+
+/*
+** Ensures final expression result (including results from its jump
+** lists) is in next available register.
+*/
+void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
+  luaK_dischargevars(fs, e);
+  freeexp(fs, e);
+  luaK_reserveregs(fs, 1);
+  exp2reg(fs, e, fs->freereg - 1);
+}
+
+
+/*
+** Ensures final expression result (including results from its jump
+** lists) is in some (any) register and return that register.
+*/
+int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
+  luaK_dischargevars(fs, e);
+  if (e->k == VNONRELOC) {  /* expression already has a register? */
+    if (!hasjumps(e))  /* no jumps? */
+      return e->u.info;  /* result is already in a register */
+    if (e->u.info >= fs->nactvar) {  /* reg. is not a local? */
+      exp2reg(fs, e, e->u.info);  /* put final result in it */
+      return e->u.info;
+    }
+  }
+  luaK_exp2nextreg(fs, e);  /* otherwise, use next available register */
+  return e->u.info;
+}
+
+
+/*
+** Ensures final expression result is either in a register or in an
+** upvalue.
+*/
+void luaK_exp2anyregup (FuncState *fs, expdesc *e) {
+  if (e->k != VUPVAL || hasjumps(e))
+    luaK_exp2anyreg(fs, e);
+}
+
+
+/*
+** Ensures final expression result is either in a register or it is
+** a constant.
+*/
+void luaK_exp2val (FuncState *fs, expdesc *e) {
+  if (hasjumps(e))
+    luaK_exp2anyreg(fs, e);
+  else
+    luaK_dischargevars(fs, e);
+}
+
+
+/*
+** Ensures final expression result is in a valid R/K index
+** (that is, it is either in a register or in 'k' with an index
+** in the range of R/K indices).
+** Returns R/K index.
+*/  
+int luaK_exp2RK (FuncState *fs, expdesc *e) {
+  luaK_exp2val(fs, e);
+  switch (e->k) {  /* move constants to 'k' */
+    case VTRUE: e->u.info = boolK(fs, 1); goto vk;
+    case VFALSE: e->u.info = boolK(fs, 0); goto vk;
+    case VNIL: e->u.info = nilK(fs); goto vk;
+    case VKINT: e->u.info = luaK_intK(fs, e->u.ival); goto vk;
+    case VKFLT: e->u.info = luaK_numberK(fs, e->u.nval); goto vk;
+    case VK:
+     vk:
+      e->k = VK;
+      if (e->u.info <= MAXINDEXRK)  /* constant fits in 'argC'? */
+        return RKASK(e->u.info);
+      else break;
+    default: break;
+  }
+  /* not a constant in the right range: put it in a register */
+  return luaK_exp2anyreg(fs, e);
+}
+
+
+/*
+** Generate code to store result of expression 'ex' into variable 'var'.
+*/
+void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
+  switch (var->k) {
+    case VLOCAL: {
+      freeexp(fs, ex);
+      exp2reg(fs, ex, var->u.info);  /* compute 'ex' into proper place */
+      return;
+    }
+    case VUPVAL: {
+      int e = luaK_exp2anyreg(fs, ex);
+      luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0);
+      break;
+    }
+    case VINDEXED: {
+      OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP;
+      int e = luaK_exp2RK(fs, ex);
+      luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e);
+      break;
+    }
+    default: lua_assert(0);  /* invalid var kind to store */
+  }
+  freeexp(fs, ex);
+}
+
+
+/*
+** Emit SELF instruction (convert expression 'e' into 'e:key(e,').
+*/
+void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
+  int ereg;
+  luaK_exp2anyreg(fs, e);
+  ereg = e->u.info;  /* register where 'e' was placed */
+  freeexp(fs, e);
+  e->u.info = fs->freereg;  /* base register for op_self */
+  e->k = VNONRELOC;  /* self expression has a fixed register */
+  luaK_reserveregs(fs, 2);  /* function and 'self' produced by op_self */
+  luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key));
+  freeexp(fs, key);
+}
+
+
+/*
+** Negate condition 'e' (where 'e' is a comparison).
+*/
+static void negatecondition (FuncState *fs, expdesc *e) {
+  Instruction *pc = getjumpcontrol(fs, e->u.info);
+  lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
+                                           GET_OPCODE(*pc) != OP_TEST);
+  SETARG_A(*pc, !(GETARG_A(*pc)));
+}
+
+
+/*
+** Emit instruction to jump if 'e' is 'cond' (that is, if 'cond'
+** is true, code will jump if 'e' is true.) Return jump position.
+** Optimize when 'e' is 'not' something, inverting the condition
+** and removing the 'not'.
+*/
+static int jumponcond (FuncState *fs, expdesc *e, int cond) {
+  if (e->k == VRELOCABLE) {
+    Instruction ie = getinstruction(fs, e);
+    if (GET_OPCODE(ie) == OP_NOT) {
+      fs->pc--;  /* remove previous OP_NOT */
+      return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
+    }
+    /* else go through */
+  }
+  discharge2anyreg(fs, e);
+  freeexp(fs, e);
+  return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond);
+}
+
+
+/*
+** Emit code to go through if 'e' is true, jump otherwise.
+*/
+void luaK_goiftrue (FuncState *fs, expdesc *e) {
+  int pc;  /* pc of new jump */
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VJMP: {  /* condition? */
+      negatecondition(fs, e);  /* jump when it is false */
+      pc = e->u.info;  /* save jump position */
+      break;
+    }
+    case VK: case VKFLT: case VKINT: case VTRUE: {
+      pc = NO_JUMP;  /* always true; do nothing */
+      break;
+    }
+    default: {
+      pc = jumponcond(fs, e, 0);  /* jump when false */
+      break;
+    }
+  }
+  luaK_concat(fs, &e->f, pc);  /* insert new jump in false list */
+  luaK_patchtohere(fs, e->t);  /* true list jumps to here (to go through) */
+  e->t = NO_JUMP;
+}
+
+
+/*
+** Emit code to go through if 'e' is false, jump otherwise.
+*/
+void luaK_goiffalse (FuncState *fs, expdesc *e) {
+  int pc;  /* pc of new jump */
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VJMP: {
+      pc = e->u.info;  /* already jump if true */
+      break;
+    }
+    case VNIL: case VFALSE: {
+      pc = NO_JUMP;  /* always false; do nothing */
+      break;
+    }
+    default: {
+      pc = jumponcond(fs, e, 1);  /* jump if true */
+      break;
+    }
+  }
+  luaK_concat(fs, &e->t, pc);  /* insert new jump in 't' list */
+  luaK_patchtohere(fs, e->f);  /* false list jumps to here (to go through) */
+  e->f = NO_JUMP;
+}
+
+
+/*
+** Code 'not e', doing constant folding.
+*/
+static void codenot (FuncState *fs, expdesc *e) {
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VNIL: case VFALSE: {
+      e->k = VTRUE;  /* true == not nil == not false */
+      break;
+    }
+    case VK: case VKFLT: case VKINT: case VTRUE: {
+      e->k = VFALSE;  /* false == not "x" == not 0.5 == not 1 == not true */
+      break;
+    }
+    case VJMP: {
+      negatecondition(fs, e);
+      break;
+    }
+    case VRELOCABLE:
+    case VNONRELOC: {
+      discharge2anyreg(fs, e);
+      freeexp(fs, e);
+      e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0);
+      e->k = VRELOCABLE;
+      break;
+    }
+    default: lua_assert(0);  /* cannot happen */
+  }
+  /* interchange true and false lists */
+  { int temp = e->f; e->f = e->t; e->t = temp; }
+  removevalues(fs, e->f);  /* values are useless when negated */
+  removevalues(fs, e->t);
+}
+
+
+/*
+** Create expression 't[k]'. 't' must have its final result already in a
+** register or upvalue.
+*/
+void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
+  lua_assert(!hasjumps(t) && (vkisinreg(t->k) || t->k == VUPVAL));
+  t->u.ind.t = t->u.info;  /* register or upvalue index */
+  t->u.ind.idx = luaK_exp2RK(fs, k);  /* R/K index for key */
+  t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL : VLOCAL;
+  t->k = VINDEXED;
+}
+
+
+/*
+** Return false if folding can raise an error.
+** Bitwise operations need operands convertible to integers; division
+** operations cannot have 0 as divisor.
+*/
+static int validop (int op, TValue *v1, TValue *v2) {
+  switch (op) {
+    case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
+    case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: {  /* conversion errors */
+      lua_Integer i;
+      return (tointeger(v1, &i) && tointeger(v2, &i));
+    }
+    case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD:  /* division by 0 */
+      return (nvalue(v2) != 0);
+    default: return 1;  /* everything else is valid */
+  }
+}
+
+
+/*
+** Try to "constant-fold" an operation; return 1 iff successful.
+** (In this case, 'e1' has the final result.)
+*/
+static int constfolding (FuncState *fs, int op, expdesc *e1, expdesc *e2) {
+  TValue v1, v2, res;
+  if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2))
+    return 0;  /* non-numeric operands or not safe to fold */
+  luaO_arith(fs->ls->L, op, &v1, &v2, &res);  /* does operation */
+  if (ttisinteger(&res)) {
+    e1->k = VKINT;
+    e1->u.ival = ivalue(&res);
+  }
+  else {  /* folds neither NaN nor 0.0 (to avoid problems with -0.0) */
+    lua_Number n = fltvalue(&res);
+    if (luai_numisnan(n) || n == 0)
+      return 0;
+    e1->k = VKFLT;
+    e1->u.nval = n;
+  }
+  return 1;
+}
+
+
+/*
+** Emit code for unary expressions that "produce values"
+** (everything but 'not').
+** Expression to produce final result will be encoded in 'e'.
+*/
+static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) {
+  int r = luaK_exp2anyreg(fs, e);  /* opcodes operate only on registers */
+  freeexp(fs, e);
+  e->u.info = luaK_codeABC(fs, op, 0, r, 0);  /* generate opcode */
+  e->k = VRELOCABLE;  /* all those operations are relocatable */
+  luaK_fixline(fs, line);
+}
+
+
+/*
+** Emit code for binary expressions that "produce values"
+** (everything but logical operators 'and'/'or' and comparison
+** operators).
+** Expression to produce final result will be encoded in 'e1'.
+*/
+static void codebinexpval (FuncState *fs, OpCode op,
+                           expdesc *e1, expdesc *e2, int line) {
+  int rk1 = luaK_exp2RK(fs, e1);  /* both operands are "RK" */
+  int rk2 = luaK_exp2RK(fs, e2);
+  freeexps(fs, e1, e2);
+  e1->u.info = luaK_codeABC(fs, op, 0, rk1, rk2);  /* generate opcode */
+  e1->k = VRELOCABLE;  /* all those operations are relocatable */
+  luaK_fixline(fs, line);
+}
+
+
+/*
+** Emit code for comparisons.
+** 'e1' was already put in R/K form by 'luaK_infix'.
+*/
+static void codecomp (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
+  int rk1 = (e1->k == VK) ? RKASK(e1->u.info)
+                          : check_exp(e1->k == VNONRELOC, e1->u.info);
+  int rk2 = luaK_exp2RK(fs, e2);
+  freeexps(fs, e1, e2);
+  switch (opr) {
+    case OPR_NE: {  /* '(a ~= b)' ==> 'not (a == b)' */
+      e1->u.info = condjump(fs, OP_EQ, 0, rk1, rk2);
+      break;
+    }
+    case OPR_GT: case OPR_GE: {
+      /* '(a > b)' ==> '(b < a)';  '(a >= b)' ==> '(b <= a)' */
+      OpCode op = cast(OpCode, (opr - OPR_NE) + OP_EQ);
+      e1->u.info = condjump(fs, op, 1, rk2, rk1);  /* invert operands */
+      break;
+    }
+    default: {  /* '==', '<', '<=' use their own opcodes */
+      OpCode op = cast(OpCode, (opr - OPR_EQ) + OP_EQ);
+      e1->u.info = condjump(fs, op, 1, rk1, rk2);
+      break;
+    }
+  }
+  e1->k = VJMP;
+}
+
+
+/*
+** Aplly prefix operation 'op' to expression 'e'.
+*/
+void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {
+  static expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP};  /* fake 2nd operand */
+  switch (op) {
+    case OPR_MINUS: case OPR_BNOT:
+      if (constfolding(fs, op + LUA_OPUNM, e, &ef))
+        break;
+      /* FALLTHROUGH */
+    case OPR_LEN:
+      codeunexpval(fs, cast(OpCode, op + OP_UNM), e, line);
+      break;
+    case OPR_NOT: codenot(fs, e); break;
+    default: lua_assert(0);
+  }
+}
+
+
+/*
+** Process 1st operand 'v' of binary operation 'op' before reading
+** 2nd operand.
+*/
+void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
+  switch (op) {
+    case OPR_AND: {
+      luaK_goiftrue(fs, v);  /* go ahead only if 'v' is true */
+      break;
+    }
+    case OPR_OR: {
+      luaK_goiffalse(fs, v);  /* go ahead only if 'v' is false */
+      break;
+    }
+    case OPR_CONCAT: {
+      luaK_exp2nextreg(fs, v);  /* operand must be on the 'stack' */
+      break;
+    }
+    case OPR_ADD: case OPR_SUB:
+    case OPR_MUL: case OPR_DIV: case OPR_IDIV:
+    case OPR_MOD: case OPR_POW:
+    case OPR_BAND: case OPR_BOR: case OPR_BXOR:
+    case OPR_SHL: case OPR_SHR: {
+      if (!tonumeral(v, NULL))
+        luaK_exp2RK(fs, v);
+      /* else keep numeral, which may be folded with 2nd operand */
+      break;
+    }
+    default: {
+      luaK_exp2RK(fs, v);
+      break;
+    }
+  }
+}
+
+
+/*
+** Finalize code for binary operation, after reading 2nd operand.
+** For '(a .. b .. c)' (which is '(a .. (b .. c))', because
+** concatenation is right associative), merge second CONCAT into first
+** one.
+*/
+void luaK_posfix (FuncState *fs, BinOpr op,
+                  expdesc *e1, expdesc *e2, int line) {
+  switch (op) {
+    case OPR_AND: {
+      lua_assert(e1->t == NO_JUMP);  /* list closed by 'luK_infix' */
+      luaK_dischargevars(fs, e2);
+      luaK_concat(fs, &e2->f, e1->f);
+      *e1 = *e2;
+      break;
+    }
+    case OPR_OR: {
+      lua_assert(e1->f == NO_JUMP);  /* list closed by 'luK_infix' */
+      luaK_dischargevars(fs, e2);
+      luaK_concat(fs, &e2->t, e1->t);
+      *e1 = *e2;
+      break;
+    }
+    case OPR_CONCAT: {
+      luaK_exp2val(fs, e2);
+      if (e2->k == VRELOCABLE &&
+          GET_OPCODE(getinstruction(fs, e2)) == OP_CONCAT) {
+        lua_assert(e1->u.info == GETARG_B(getinstruction(fs, e2))-1);
+        freeexp(fs, e1);
+        SETARG_B(getinstruction(fs, e2), e1->u.info);
+        e1->k = VRELOCABLE; e1->u.info = e2->u.info;
+      }
+      else {
+        luaK_exp2nextreg(fs, e2);  /* operand must be on the 'stack' */
+        codebinexpval(fs, OP_CONCAT, e1, e2, line);
+      }
+      break;
+    }
+    case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
+    case OPR_IDIV: case OPR_MOD: case OPR_POW:
+    case OPR_BAND: case OPR_BOR: case OPR_BXOR:
+    case OPR_SHL: case OPR_SHR: {
+      if (!constfolding(fs, op + LUA_OPADD, e1, e2))
+        codebinexpval(fs, cast(OpCode, op + OP_ADD), e1, e2, line);
+      break;
+    }
+    case OPR_EQ: case OPR_LT: case OPR_LE:
+    case OPR_NE: case OPR_GT: case OPR_GE: {
+      codecomp(fs, op, e1, e2);
+      break;
+    }
+    default: lua_assert(0);
+  }
+}
+
+
+/*
+** Change line information associated with current position.
+*/
+void luaK_fixline (FuncState *fs, int line) {
+  fs->f->lineinfo[fs->pc - 1] = line;
+}
+
+
+/*
+** Emit a SETLIST instruction.
+** 'base' is register that keeps table;
+** 'nelems' is #table plus those to be stored now;
+** 'tostore' is number of values (in registers 'base + 1',...) to add to
+** table (or LUA_MULTRET to add up to stack top).
+*/
+void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
+  int c =  (nelems - 1)/LFIELDS_PER_FLUSH + 1;
+  int b = (tostore == LUA_MULTRET) ? 0 : tostore;
+  lua_assert(tostore != 0 && tostore <= LFIELDS_PER_FLUSH);
+  if (c <= MAXARG_C)
+    luaK_codeABC(fs, OP_SETLIST, base, b, c);
+  else if (c <= MAXARG_Ax) {
+    luaK_codeABC(fs, OP_SETLIST, base, b, 0);
+    codeextraarg(fs, c);
+  }
+  else
+    luaX_syntaxerror(fs->ls, "constructor too long");
+  fs->freereg = base + 1;  /* free registers with list values */
+}
+
diff --git a/src/lcode.h b/src/lcode.h
new file mode 100644
index 0000000..cd306d5
--- /dev/null
+++ b/src/lcode.h
@@ -0,0 +1,88 @@
+/*
+** $Id: lcode.h,v 1.64 2016/01/05 16:22:37 roberto Exp $
+** Code generator for Lua
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lcode_h
+#define lcode_h
+
+#include "llex.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lparser.h"
+
+
+/*
+** Marks the end of a patch list. It is an invalid value both as an absolute
+** address, and as a list link (would link an element to itself).
+*/
+#define NO_JUMP (-1)
+
+
+/*
+** grep "ORDER OPR" if you change these enums  (ORDER OP)
+*/
+typedef enum BinOpr {
+  OPR_ADD, OPR_SUB, OPR_MUL, OPR_MOD, OPR_POW,
+  OPR_DIV,
+  OPR_IDIV,
+  OPR_BAND, OPR_BOR, OPR_BXOR,
+  OPR_SHL, OPR_SHR,
+  OPR_CONCAT,
+  OPR_EQ, OPR_LT, OPR_LE,
+  OPR_NE, OPR_GT, OPR_GE,
+  OPR_AND, OPR_OR,
+  OPR_NOBINOPR
+} BinOpr;
+
+
+typedef enum UnOpr { OPR_MINUS, OPR_BNOT, OPR_NOT, OPR_LEN, OPR_NOUNOPR } UnOpr;
+
+
+/* get (pointer to) instruction of given 'expdesc' */
+#define getinstruction(fs,e)	((fs)->f->code[(e)->u.info])
+
+#define luaK_codeAsBx(fs,o,A,sBx)	luaK_codeABx(fs,o,A,(sBx)+MAXARG_sBx)
+
+#define luaK_setmultret(fs,e)	luaK_setreturns(fs, e, LUA_MULTRET)
+
+#define luaK_jumpto(fs,t)	luaK_patchlist(fs, luaK_jump(fs), t)
+
+LUAI_FUNC int luaK_codeABx (FuncState *fs, OpCode o, int A, unsigned int Bx);
+LUAI_FUNC int luaK_codeABC (FuncState *fs, OpCode o, int A, int B, int C);
+LUAI_FUNC int luaK_codek (FuncState *fs, int reg, int k);
+LUAI_FUNC void luaK_fixline (FuncState *fs, int line);
+LUAI_FUNC void luaK_nil (FuncState *fs, int from, int n);
+LUAI_FUNC void luaK_reserveregs (FuncState *fs, int n);
+LUAI_FUNC void luaK_checkstack (FuncState *fs, int n);
+LUAI_FUNC int luaK_stringK (FuncState *fs, TString *s);
+LUAI_FUNC int luaK_intK (FuncState *fs, lua_Integer n);
+LUAI_FUNC void luaK_dischargevars (FuncState *fs, expdesc *e);
+LUAI_FUNC int luaK_exp2anyreg (FuncState *fs, expdesc *e);
+LUAI_FUNC void luaK_exp2anyregup (FuncState *fs, expdesc *e);
+LUAI_FUNC void luaK_exp2nextreg (FuncState *fs, expdesc *e);
+LUAI_FUNC void luaK_exp2val (FuncState *fs, expdesc *e);
+LUAI_FUNC int luaK_exp2RK (FuncState *fs, expdesc *e);
+LUAI_FUNC void luaK_self (FuncState *fs, expdesc *e, expdesc *key);
+LUAI_FUNC void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k);
+LUAI_FUNC void luaK_goiftrue (FuncState *fs, expdesc *e);
+LUAI_FUNC void luaK_goiffalse (FuncState *fs, expdesc *e);
+LUAI_FUNC void luaK_storevar (FuncState *fs, expdesc *var, expdesc *e);
+LUAI_FUNC void luaK_setreturns (FuncState *fs, expdesc *e, int nresults);
+LUAI_FUNC void luaK_setoneret (FuncState *fs, expdesc *e);
+LUAI_FUNC int luaK_jump (FuncState *fs);
+LUAI_FUNC void luaK_ret (FuncState *fs, int first, int nret);
+LUAI_FUNC void luaK_patchlist (FuncState *fs, int list, int target);
+LUAI_FUNC void luaK_patchtohere (FuncState *fs, int list);
+LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level);
+LUAI_FUNC void luaK_concat (FuncState *fs, int *l1, int l2);
+LUAI_FUNC int luaK_getlabel (FuncState *fs);
+LUAI_FUNC void luaK_prefix (FuncState *fs, UnOpr op, expdesc *v, int line);
+LUAI_FUNC void luaK_infix (FuncState *fs, BinOpr op, expdesc *v);
+LUAI_FUNC void luaK_posfix (FuncState *fs, BinOpr op, expdesc *v1,
+                            expdesc *v2, int line);
+LUAI_FUNC void luaK_setlist (FuncState *fs, int base, int nelems, int tostore);
+
+
+#endif
diff --git a/src/lcorolib.c b/src/lcorolib.c
new file mode 100644
index 0000000..2303429
--- /dev/null
+++ b/src/lcorolib.c
@@ -0,0 +1,168 @@
+/*
+** $Id: lcorolib.c,v 1.10 2016/04/11 19:19:55 roberto Exp $
+** Coroutine Library
+** See Copyright Notice in lua.h
+*/
+
+#define lcorolib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <stdlib.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+static lua_State *getco (lua_State *L) {
+  lua_State *co = lua_tothread(L, 1);
+  luaL_argcheck(L, co, 1, "thread expected");
+  return co;
+}
+
+
+static int auxresume (lua_State *L, lua_State *co, int narg) {
+  int status;
+  if (!lua_checkstack(co, narg)) {
+    lua_pushliteral(L, "too many arguments to resume");
+    return -1;  /* error flag */
+  }
+  if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
+    lua_pushliteral(L, "cannot resume dead coroutine");
+    return -1;  /* error flag */
+  }
+  lua_xmove(L, co, narg);
+  status = lua_resume(co, L, narg);
+  if (status == LUA_OK || status == LUA_YIELD) {
+    int nres = lua_gettop(co);
+    if (!lua_checkstack(L, nres + 1)) {
+      lua_pop(co, nres);  /* remove results anyway */
+      lua_pushliteral(L, "too many results to resume");
+      return -1;  /* error flag */
+    }
+    lua_xmove(co, L, nres);  /* move yielded values */
+    return nres;
+  }
+  else {
+    lua_xmove(co, L, 1);  /* move error message */
+    return -1;  /* error flag */
+  }
+}
+
+
+static int luaB_coresume (lua_State *L) {
+  lua_State *co = getco(L);
+  int r;
+  r = auxresume(L, co, lua_gettop(L) - 1);
+  if (r < 0) {
+    lua_pushboolean(L, 0);
+    lua_insert(L, -2);
+    return 2;  /* return false + error message */
+  }
+  else {
+    lua_pushboolean(L, 1);
+    lua_insert(L, -(r + 1));
+    return r + 1;  /* return true + 'resume' returns */
+  }
+}
+
+
+static int luaB_auxwrap (lua_State *L) {
+  lua_State *co = lua_tothread(L, lua_upvalueindex(1));
+  int r = auxresume(L, co, lua_gettop(L));
+  if (r < 0) {
+    if (lua_type(L, -1) == LUA_TSTRING) {  /* error object is a string? */
+      luaL_where(L, 1);  /* add extra info */
+      lua_insert(L, -2);
+      lua_concat(L, 2);
+    }
+    return lua_error(L);  /* propagate error */
+  }
+  return r;
+}
+
+
+static int luaB_cocreate (lua_State *L) {
+  lua_State *NL;
+  luaL_checktype(L, 1, LUA_TFUNCTION);
+  NL = lua_newthread(L);
+  lua_pushvalue(L, 1);  /* move function to top */
+  lua_xmove(L, NL, 1);  /* move function from L to NL */
+  return 1;
+}
+
+
+static int luaB_cowrap (lua_State *L) {
+  luaB_cocreate(L);
+  lua_pushcclosure(L, luaB_auxwrap, 1);
+  return 1;
+}
+
+
+static int luaB_yield (lua_State *L) {
+  return lua_yield(L, lua_gettop(L));
+}
+
+
+static int luaB_costatus (lua_State *L) {
+  lua_State *co = getco(L);
+  if (L == co) lua_pushliteral(L, "running");
+  else {
+    switch (lua_status(co)) {
+      case LUA_YIELD:
+        lua_pushliteral(L, "suspended");
+        break;
+      case LUA_OK: {
+        lua_Debug ar;
+        if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
+          lua_pushliteral(L, "normal");  /* it is running */
+        else if (lua_gettop(co) == 0)
+            lua_pushliteral(L, "dead");
+        else
+          lua_pushliteral(L, "suspended");  /* initial state */
+        break;
+      }
+      default:  /* some error occurred */
+        lua_pushliteral(L, "dead");
+        break;
+    }
+  }
+  return 1;
+}
+
+
+static int luaB_yieldable (lua_State *L) {
+  lua_pushboolean(L, lua_isyieldable(L));
+  return 1;
+}
+
+
+static int luaB_corunning (lua_State *L) {
+  int ismain = lua_pushthread(L);
+  lua_pushboolean(L, ismain);
+  return 2;
+}
+
+
+static const luaL_Reg co_funcs[] = {
+  {"create", luaB_cocreate},
+  {"resume", luaB_coresume},
+  {"running", luaB_corunning},
+  {"status", luaB_costatus},
+  {"wrap", luaB_cowrap},
+  {"yield", luaB_yield},
+  {"isyieldable", luaB_yieldable},
+  {NULL, NULL}
+};
+
+
+
+LUAMOD_API int luaopen_coroutine (lua_State *L) {
+  luaL_newlib(L, co_funcs);
+  return 1;
+}
+
diff --git a/src/lctype.c b/src/lctype.c
new file mode 100644
index 0000000..ae9367e
--- /dev/null
+++ b/src/lctype.c
@@ -0,0 +1,55 @@
+/*
+** $Id: lctype.c,v 1.12 2014/11/02 19:19:04 roberto Exp $
+** 'ctype' functions for Lua
+** See Copyright Notice in lua.h
+*/
+
+#define lctype_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include "lctype.h"
+
+#if !LUA_USE_CTYPE	/* { */
+
+#include <limits.h>
+
+LUAI_DDEF const lu_byte luai_ctype_[UCHAR_MAX + 2] = {
+  0x00,  /* EOZ */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 0. */
+  0x00,  0x08,  0x08,  0x08,  0x08,  0x08,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 1. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x0c,  0x04,  0x04,  0x04,  0x04,  0x04,  0x04,  0x04,	/* 2. */
+  0x04,  0x04,  0x04,  0x04,  0x04,  0x04,  0x04,  0x04,
+  0x16,  0x16,  0x16,  0x16,  0x16,  0x16,  0x16,  0x16,	/* 3. */
+  0x16,  0x16,  0x04,  0x04,  0x04,  0x04,  0x04,  0x04,
+  0x04,  0x15,  0x15,  0x15,  0x15,  0x15,  0x15,  0x05,	/* 4. */
+  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,
+  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,	/* 5. */
+  0x05,  0x05,  0x05,  0x04,  0x04,  0x04,  0x04,  0x05,
+  0x04,  0x15,  0x15,  0x15,  0x15,  0x15,  0x15,  0x05,	/* 6. */
+  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,
+  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,	/* 7. */
+  0x05,  0x05,  0x05,  0x04,  0x04,  0x04,  0x04,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 8. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 9. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* a. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* b. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* c. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* d. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* e. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* f. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+};
+
+#endif			/* } */
diff --git a/src/lctype.h b/src/lctype.h
new file mode 100644
index 0000000..99c7d12
--- /dev/null
+++ b/src/lctype.h
@@ -0,0 +1,95 @@
+/*
+** $Id: lctype.h,v 1.12 2011/07/15 12:50:29 roberto Exp $
+** 'ctype' functions for Lua
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lctype_h
+#define lctype_h
+
+#include "lua.h"
+
+
+/*
+** WARNING: the functions defined here do not necessarily correspond
+** to the similar functions in the standard C ctype.h. They are
+** optimized for the specific needs of Lua
+*/
+
+#if !defined(LUA_USE_CTYPE)
+
+#if 'A' == 65 && '0' == 48
+/* ASCII case: can use its own tables; faster and fixed */
+#define LUA_USE_CTYPE	0
+#else
+/* must use standard C ctype */
+#define LUA_USE_CTYPE	1
+#endif
+
+#endif
+
+
+#if !LUA_USE_CTYPE	/* { */
+
+#include <limits.h>
+
+#include "llimits.h"
+
+
+#define ALPHABIT	0
+#define DIGITBIT	1
+#define PRINTBIT	2
+#define SPACEBIT	3
+#define XDIGITBIT	4
+
+
+#define MASK(B)		(1 << (B))
+
+
+/*
+** add 1 to char to allow index -1 (EOZ)
+*/
+#define testprop(c,p)	(luai_ctype_[(c)+1] & (p))
+
+/*
+** 'lalpha' (Lua alphabetic) and 'lalnum' (Lua alphanumeric) both include '_'
+*/
+#define lislalpha(c)	testprop(c, MASK(ALPHABIT))
+#define lislalnum(c)	testprop(c, (MASK(ALPHABIT) | MASK(DIGITBIT)))
+#define lisdigit(c)	testprop(c, MASK(DIGITBIT))
+#define lisspace(c)	testprop(c, MASK(SPACEBIT))
+#define lisprint(c)	testprop(c, MASK(PRINTBIT))
+#define lisxdigit(c)	testprop(c, MASK(XDIGITBIT))
+
+/*
+** this 'ltolower' only works for alphabetic characters
+*/
+#define ltolower(c)	((c) | ('A' ^ 'a'))
+
+
+/* two more entries for 0 and -1 (EOZ) */
+LUAI_DDEC const lu_byte luai_ctype_[UCHAR_MAX + 2];
+
+
+#else			/* }{ */
+
+/*
+** use standard C ctypes
+*/
+
+#include <ctype.h>
+
+
+#define lislalpha(c)	(isalpha(c) || (c) == '_')
+#define lislalnum(c)	(isalnum(c) || (c) == '_')
+#define lisdigit(c)	(isdigit(c))
+#define lisspace(c)	(isspace(c))
+#define lisprint(c)	(isprint(c))
+#define lisxdigit(c)	(isxdigit(c))
+
+#define ltolower(c)	(tolower(c))
+
+#endif			/* } */
+
+#endif
+
diff --git a/src/ldblib.c b/src/ldblib.c
new file mode 100644
index 0000000..786f6cd
--- /dev/null
+++ b/src/ldblib.c
@@ -0,0 +1,456 @@
+/*
+** $Id: ldblib.c,v 1.151 2015/11/23 11:29:43 roberto Exp $
+** Interface from Lua to its debug API
+** See Copyright Notice in lua.h
+*/
+
+#define ldblib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** The hook table at registry[&HOOKKEY] maps threads to their current
+** hook function. (We only need the unique address of 'HOOKKEY'.)
+*/
+static const int HOOKKEY = 0;
+
+
+/*
+** If L1 != L, L1 can be in any state, and therefore there are no
+** guarantees about its stack space; any push in L1 must be
+** checked.
+*/
+static void checkstack (lua_State *L, lua_State *L1, int n) {
+  if (L != L1 && !lua_checkstack(L1, n))
+    luaL_error(L, "stack overflow");
+}
+
+
+static int db_getregistry (lua_State *L) {
+  lua_pushvalue(L, LUA_REGISTRYINDEX);
+  return 1;
+}
+
+
+static int db_getmetatable (lua_State *L) {
+  luaL_checkany(L, 1);
+  if (!lua_getmetatable(L, 1)) {
+    lua_pushnil(L);  /* no metatable */
+  }
+  return 1;
+}
+
+
+static int db_setmetatable (lua_State *L) {
+  int t = lua_type(L, 2);
+  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
+                    "nil or table expected");
+  lua_settop(L, 2);
+  lua_setmetatable(L, 1);
+  return 1;  /* return 1st argument */
+}
+
+
+static int db_getuservalue (lua_State *L) {
+  if (lua_type(L, 1) != LUA_TUSERDATA)
+    lua_pushnil(L);
+  else
+    lua_getuservalue(L, 1);
+  return 1;
+}
+
+
+static int db_setuservalue (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TUSERDATA);
+  luaL_checkany(L, 2);
+  lua_settop(L, 2);
+  lua_setuservalue(L, 1);
+  return 1;
+}
+
+
+/*
+** Auxiliary function used by several library functions: check for
+** an optional thread as function's first argument and set 'arg' with
+** 1 if this argument is present (so that functions can skip it to
+** access their other arguments)
+*/
+static lua_State *getthread (lua_State *L, int *arg) {
+  if (lua_isthread(L, 1)) {
+    *arg = 1;
+    return lua_tothread(L, 1);
+  }
+  else {
+    *arg = 0;
+    return L;  /* function will operate over current thread */
+  }
+}
+
+
+/*
+** Variations of 'lua_settable', used by 'db_getinfo' to put results
+** from 'lua_getinfo' into result table. Key is always a string;
+** value can be a string, an int, or a boolean.
+*/
+static void settabss (lua_State *L, const char *k, const char *v) {
+  lua_pushstring(L, v);
+  lua_setfield(L, -2, k);
+}
+
+static void settabsi (lua_State *L, const char *k, int v) {
+  lua_pushinteger(L, v);
+  lua_setfield(L, -2, k);
+}
+
+static void settabsb (lua_State *L, const char *k, int v) {
+  lua_pushboolean(L, v);
+  lua_setfield(L, -2, k);
+}
+
+
+/*
+** In function 'db_getinfo', the call to 'lua_getinfo' may push
+** results on the stack; later it creates the result table to put
+** these objects. Function 'treatstackoption' puts the result from
+** 'lua_getinfo' on top of the result table so that it can call
+** 'lua_setfield'.
+*/
+static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
+  if (L == L1)
+    lua_rotate(L, -2, 1);  /* exchange object and table */
+  else
+    lua_xmove(L1, L, 1);  /* move object to the "main" stack */
+  lua_setfield(L, -2, fname);  /* put object into table */
+}
+
+
+/*
+** Calls 'lua_getinfo' and collects all results in a new table.
+** L1 needs stack space for an optional input (function) plus
+** two optional outputs (function and line table) from function
+** 'lua_getinfo'.
+*/
+static int db_getinfo (lua_State *L) {
+  lua_Debug ar;
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  const char *options = luaL_optstring(L, arg+2, "flnStu");
+  checkstack(L, L1, 3);
+  if (lua_isfunction(L, arg + 1)) {  /* info about a function? */
+    options = lua_pushfstring(L, ">%s", options);  /* add '>' to 'options' */
+    lua_pushvalue(L, arg + 1);  /* move function to 'L1' stack */
+    lua_xmove(L, L1, 1);
+  }
+  else {  /* stack level */
+    if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) {
+      lua_pushnil(L);  /* level out of range */
+      return 1;
+    }
+  }
+  if (!lua_getinfo(L1, options, &ar))
+    return luaL_argerror(L, arg+2, "invalid option");
+  lua_newtable(L);  /* table to collect results */
+  if (strchr(options, 'S')) {
+    settabss(L, "source", ar.source);
+    settabss(L, "short_src", ar.short_src);
+    settabsi(L, "linedefined", ar.linedefined);
+    settabsi(L, "lastlinedefined", ar.lastlinedefined);
+    settabss(L, "what", ar.what);
+  }
+  if (strchr(options, 'l'))
+    settabsi(L, "currentline", ar.currentline);
+  if (strchr(options, 'u')) {
+    settabsi(L, "nups", ar.nups);
+    settabsi(L, "nparams", ar.nparams);
+    settabsb(L, "isvararg", ar.isvararg);
+  }
+  if (strchr(options, 'n')) {
+    settabss(L, "name", ar.name);
+    settabss(L, "namewhat", ar.namewhat);
+  }
+  if (strchr(options, 't'))
+    settabsb(L, "istailcall", ar.istailcall);
+  if (strchr(options, 'L'))
+    treatstackoption(L, L1, "activelines");
+  if (strchr(options, 'f'))
+    treatstackoption(L, L1, "func");
+  return 1;  /* return table */
+}
+
+
+static int db_getlocal (lua_State *L) {
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  lua_Debug ar;
+  const char *name;
+  int nvar = (int)luaL_checkinteger(L, arg + 2);  /* local-variable index */
+  if (lua_isfunction(L, arg + 1)) {  /* function argument? */
+    lua_pushvalue(L, arg + 1);  /* push function */
+    lua_pushstring(L, lua_getlocal(L, NULL, nvar));  /* push local name */
+    return 1;  /* return only name (there is no value) */
+  }
+  else {  /* stack-level argument */
+    int level = (int)luaL_checkinteger(L, arg + 1);
+    if (!lua_getstack(L1, level, &ar))  /* out of range? */
+      return luaL_argerror(L, arg+1, "level out of range");
+    checkstack(L, L1, 1);
+    name = lua_getlocal(L1, &ar, nvar);
+    if (name) {
+      lua_xmove(L1, L, 1);  /* move local value */
+      lua_pushstring(L, name);  /* push name */
+      lua_rotate(L, -2, 1);  /* re-order */
+      return 2;
+    }
+    else {
+      lua_pushnil(L);  /* no name (nor value) */
+      return 1;
+    }
+  }
+}
+
+
+static int db_setlocal (lua_State *L) {
+  int arg;
+  const char *name;
+  lua_State *L1 = getthread(L, &arg);
+  lua_Debug ar;
+  int level = (int)luaL_checkinteger(L, arg + 1);
+  int nvar = (int)luaL_checkinteger(L, arg + 2);
+  if (!lua_getstack(L1, level, &ar))  /* out of range? */
+    return luaL_argerror(L, arg+1, "level out of range");
+  luaL_checkany(L, arg+3);
+  lua_settop(L, arg+3);
+  checkstack(L, L1, 1);
+  lua_xmove(L, L1, 1);
+  name = lua_setlocal(L1, &ar, nvar);
+  if (name == NULL)
+    lua_pop(L1, 1);  /* pop value (if not popped by 'lua_setlocal') */
+  lua_pushstring(L, name);
+  return 1;
+}
+
+
+/*
+** get (if 'get' is true) or set an upvalue from a closure
+*/
+static int auxupvalue (lua_State *L, int get) {
+  const char *name;
+  int n = (int)luaL_checkinteger(L, 2);  /* upvalue index */
+  luaL_checktype(L, 1, LUA_TFUNCTION);  /* closure */
+  name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
+  if (name == NULL) return 0;
+  lua_pushstring(L, name);
+  lua_insert(L, -(get+1));  /* no-op if get is false */
+  return get + 1;
+}
+
+
+static int db_getupvalue (lua_State *L) {
+  return auxupvalue(L, 1);
+}
+
+
+static int db_setupvalue (lua_State *L) {
+  luaL_checkany(L, 3);
+  return auxupvalue(L, 0);
+}
+
+
+/*
+** Check whether a given upvalue from a given closure exists and
+** returns its index
+*/
+static int checkupval (lua_State *L, int argf, int argnup) {
+  int nup = (int)luaL_checkinteger(L, argnup);  /* upvalue index */
+  luaL_checktype(L, argf, LUA_TFUNCTION);  /* closure */
+  luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup,
+                   "invalid upvalue index");
+  return nup;
+}
+
+
+static int db_upvalueid (lua_State *L) {
+  int n = checkupval(L, 1, 2);
+  lua_pushlightuserdata(L, lua_upvalueid(L, 1, n));
+  return 1;
+}
+
+
+static int db_upvaluejoin (lua_State *L) {
+  int n1 = checkupval(L, 1, 2);
+  int n2 = checkupval(L, 3, 4);
+  luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");
+  luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");
+  lua_upvaluejoin(L, 1, n1, 3, n2);
+  return 0;
+}
+
+
+/*
+** Call hook function registered at hook table for the current
+** thread (if there is one)
+*/
+static void hookf (lua_State *L, lua_Debug *ar) {
+  static const char *const hooknames[] =
+    {"call", "return", "line", "count", "tail call"};
+  lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
+  lua_pushthread(L);
+  if (lua_rawget(L, -2) == LUA_TFUNCTION) {  /* is there a hook function? */
+    lua_pushstring(L, hooknames[(int)ar->event]);  /* push event name */
+    if (ar->currentline >= 0)
+      lua_pushinteger(L, ar->currentline);  /* push current line */
+    else lua_pushnil(L);
+    lua_assert(lua_getinfo(L, "lS", ar));
+    lua_call(L, 2, 0);  /* call hook function */
+  }
+}
+
+
+/*
+** Convert a string mask (for 'sethook') into a bit mask
+*/
+static int makemask (const char *smask, int count) {
+  int mask = 0;
+  if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
+  if (strchr(smask, 'r')) mask |= LUA_MASKRET;
+  if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
+  if (count > 0) mask |= LUA_MASKCOUNT;
+  return mask;
+}
+
+
+/*
+** Convert a bit mask (for 'gethook') into a string mask
+*/
+static char *unmakemask (int mask, char *smask) {
+  int i = 0;
+  if (mask & LUA_MASKCALL) smask[i++] = 'c';
+  if (mask & LUA_MASKRET) smask[i++] = 'r';
+  if (mask & LUA_MASKLINE) smask[i++] = 'l';
+  smask[i] = '\0';
+  return smask;
+}
+
+
+static int db_sethook (lua_State *L) {
+  int arg, mask, count;
+  lua_Hook func;
+  lua_State *L1 = getthread(L, &arg);
+  if (lua_isnoneornil(L, arg+1)) {  /* no hook? */
+    lua_settop(L, arg+1);
+    func = NULL; mask = 0; count = 0;  /* turn off hooks */
+  }
+  else {
+    const char *smask = luaL_checkstring(L, arg+2);
+    luaL_checktype(L, arg+1, LUA_TFUNCTION);
+    count = (int)luaL_optinteger(L, arg + 3, 0);
+    func = hookf; mask = makemask(smask, count);
+  }
+  if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) {
+    lua_createtable(L, 0, 2);  /* create a hook table */
+    lua_pushvalue(L, -1);
+    lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY);  /* set it in position */
+    lua_pushstring(L, "k");
+    lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */
+    lua_pushvalue(L, -1);
+    lua_setmetatable(L, -2);  /* setmetatable(hooktable) = hooktable */
+  }
+  checkstack(L, L1, 1);
+  lua_pushthread(L1); lua_xmove(L1, L, 1);  /* key (thread) */
+  lua_pushvalue(L, arg + 1);  /* value (hook function) */
+  lua_rawset(L, -3);  /* hooktable[L1] = new Lua hook */
+  lua_sethook(L1, func, mask, count);
+  return 0;
+}
+
+
+static int db_gethook (lua_State *L) {
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  char buff[5];
+  int mask = lua_gethookmask(L1);
+  lua_Hook hook = lua_gethook(L1);
+  if (hook == NULL)  /* no hook? */
+    lua_pushnil(L);
+  else if (hook != hookf)  /* external hook? */
+    lua_pushliteral(L, "external hook");
+  else {  /* hook table must exist */
+    lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
+    checkstack(L, L1, 1);
+    lua_pushthread(L1); lua_xmove(L1, L, 1);
+    lua_rawget(L, -2);   /* 1st result = hooktable[L1] */
+    lua_remove(L, -2);  /* remove hook table */
+  }
+  lua_pushstring(L, unmakemask(mask, buff));  /* 2nd result = mask */
+  lua_pushinteger(L, lua_gethookcount(L1));  /* 3rd result = count */
+  return 3;
+}
+
+
+static int db_debug (lua_State *L) {
+  for (;;) {
+    char buffer[250];
+    lua_writestringerror("%s", "lua_debug> ");
+    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
+        strcmp(buffer, "cont\n") == 0)
+      return 0;
+    if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
+        lua_pcall(L, 0, 0, 0))
+      lua_writestringerror("%s\n", lua_tostring(L, -1));
+    lua_settop(L, 0);  /* remove eventual returns */
+  }
+}
+
+
+static int db_traceback (lua_State *L) {
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  const char *msg = lua_tostring(L, arg + 1);
+  if (msg == NULL && !lua_isnoneornil(L, arg + 1))  /* non-string 'msg'? */
+    lua_pushvalue(L, arg + 1);  /* return it untouched */
+  else {
+    int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0);
+    luaL_traceback(L, L1, msg, level);
+  }
+  return 1;
+}
+
+
+static const luaL_Reg dblib[] = {
+  {"debug", db_debug},
+  {"getuservalue", db_getuservalue},
+  {"gethook", db_gethook},
+  {"getinfo", db_getinfo},
+  {"getlocal", db_getlocal},
+  {"getregistry", db_getregistry},
+  {"getmetatable", db_getmetatable},
+  {"getupvalue", db_getupvalue},
+  {"upvaluejoin", db_upvaluejoin},
+  {"upvalueid", db_upvalueid},
+  {"setuservalue", db_setuservalue},
+  {"sethook", db_sethook},
+  {"setlocal", db_setlocal},
+  {"setmetatable", db_setmetatable},
+  {"setupvalue", db_setupvalue},
+  {"traceback", db_traceback},
+  {NULL, NULL}
+};
+
+
+LUAMOD_API int luaopen_debug (lua_State *L) {
+  luaL_newlib(L, dblib);
+  return 1;
+}
+
diff --git a/src/ldebug.c b/src/ldebug.c
new file mode 100644
index 0000000..e499ee3
--- /dev/null
+++ b/src/ldebug.c
@@ -0,0 +1,679 @@
+/*
+** $Id: ldebug.c,v 2.120 2016/03/31 19:01:21 roberto Exp $
+** Debug Interface
+** See Copyright Notice in lua.h
+*/
+
+#define ldebug_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lapi.h"
+#include "lcode.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lvm.h"
+
+
+
+#define noLuaClosure(f)		((f) == NULL || (f)->c.tt == LUA_TCCL)
+
+
+/* Active Lua function (given call info) */
+#define ci_func(ci)		(clLvalue((ci)->func))
+
+
+static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
+
+
+static int currentpc (CallInfo *ci) {
+  lua_assert(isLua(ci));
+  return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
+}
+
+
+static int currentline (CallInfo *ci) {
+  return getfuncline(ci_func(ci)->p, currentpc(ci));
+}
+
+
+/*
+** If function yielded, its 'func' can be in the 'extra' field. The
+** next function restores 'func' to its correct value for debugging
+** purposes. (It exchanges 'func' and 'extra'; so, when called again,
+** after debugging, it also "re-restores" ** 'func' to its altered value.
+*/
+static void swapextra (lua_State *L) {
+  if (L->status == LUA_YIELD) {
+    CallInfo *ci = L->ci;  /* get function that yielded */
+    StkId temp = ci->func;  /* exchange its 'func' and 'extra' values */
+    ci->func = restorestack(L, ci->extra);
+    ci->extra = savestack(L, temp);
+  }
+}
+
+
+/*
+** This function can be called asynchronously (e.g. during a signal).
+** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
+** 'resethookcount') are for debug only, and it is no problem if they
+** get arbitrary values (causes at most one wrong hook call). 'hookmask'
+** is an atomic value. We assume that pointers are atomic too (e.g., gcc
+** ensures that for all platforms where it runs). Moreover, 'hook' is
+** always checked before being called (see 'luaD_hook').
+*/
+LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
+  if (func == NULL || mask == 0) {  /* turn off hooks? */
+    mask = 0;
+    func = NULL;
+  }
+  if (isLua(L->ci))
+    L->oldpc = L->ci->u.l.savedpc;
+  L->hook = func;
+  L->basehookcount = count;
+  resethookcount(L);
+  L->hookmask = cast_byte(mask);
+}
+
+
+LUA_API lua_Hook lua_gethook (lua_State *L) {
+  return L->hook;
+}
+
+
+LUA_API int lua_gethookmask (lua_State *L) {
+  return L->hookmask;
+}
+
+
+LUA_API int lua_gethookcount (lua_State *L) {
+  return L->basehookcount;
+}
+
+
+LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
+  int status;
+  CallInfo *ci;
+  if (level < 0) return 0;  /* invalid (negative) level */
+  lua_lock(L);
+  for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
+    level--;
+  if (level == 0 && ci != &L->base_ci) {  /* level found? */
+    status = 1;
+    ar->i_ci = ci;
+  }
+  else status = 0;  /* no such level */
+  lua_unlock(L);
+  return status;
+}
+
+
+static const char *upvalname (Proto *p, int uv) {
+  TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
+  if (s == NULL) return "?";
+  else return getstr(s);
+}
+
+
+static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
+  int nparams = clLvalue(ci->func)->p->numparams;
+  if (n >= cast_int(ci->u.l.base - ci->func) - nparams)
+    return NULL;  /* no such vararg */
+  else {
+    *pos = ci->func + nparams + n;
+    return "(*vararg)";  /* generic name for any vararg */
+  }
+}
+
+
+static const char *findlocal (lua_State *L, CallInfo *ci, int n,
+                              StkId *pos) {
+  const char *name = NULL;
+  StkId base;
+  if (isLua(ci)) {
+    if (n < 0)  /* access to vararg values? */
+      return findvararg(ci, -n, pos);
+    else {
+      base = ci->u.l.base;
+      name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
+    }
+  }
+  else
+    base = ci->func + 1;
+  if (name == NULL) {  /* no 'standard' name? */
+    StkId limit = (ci == L->ci) ? L->top : ci->next->func;
+    if (limit - base >= n && n > 0)  /* is 'n' inside 'ci' stack? */
+      name = "(*temporary)";  /* generic name for any valid slot */
+    else
+      return NULL;  /* no name */
+  }
+  *pos = base + (n - 1);
+  return name;
+}
+
+
+LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
+  const char *name;
+  lua_lock(L);
+  swapextra(L);
+  if (ar == NULL) {  /* information about non-active function? */
+    if (!isLfunction(L->top - 1))  /* not a Lua function? */
+      name = NULL;
+    else  /* consider live variables at function start (parameters) */
+      name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
+  }
+  else {  /* active function; get information through 'ar' */
+    StkId pos = NULL;  /* to avoid warnings */
+    name = findlocal(L, ar->i_ci, n, &pos);
+    if (name) {
+      setobj2s(L, L->top, pos);
+      api_incr_top(L);
+    }
+  }
+  swapextra(L);
+  lua_unlock(L);
+  return name;
+}
+
+
+LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
+  StkId pos = NULL;  /* to avoid warnings */
+  const char *name;
+  lua_lock(L);
+  swapextra(L);
+  name = findlocal(L, ar->i_ci, n, &pos);
+  if (name) {
+    setobjs2s(L, pos, L->top - 1);
+    L->top--;  /* pop value */
+  }
+  swapextra(L);
+  lua_unlock(L);
+  return name;
+}
+
+
+static void funcinfo (lua_Debug *ar, Closure *cl) {
+  if (noLuaClosure(cl)) {
+    ar->source = "=[C]";
+    ar->linedefined = -1;
+    ar->lastlinedefined = -1;
+    ar->what = "C";
+  }
+  else {
+    Proto *p = cl->l.p;
+    ar->source = p->source ? getstr(p->source) : "=?";
+    ar->linedefined = p->linedefined;
+    ar->lastlinedefined = p->lastlinedefined;
+    ar->what = (ar->linedefined == 0) ? "main" : "Lua";
+  }
+  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
+}
+
+
+static void collectvalidlines (lua_State *L, Closure *f) {
+  if (noLuaClosure(f)) {
+    setnilvalue(L->top);
+    api_incr_top(L);
+  }
+  else {
+    int i;
+    TValue v;
+    int *lineinfo = f->l.p->lineinfo;
+    Table *t = luaH_new(L);  /* new table to store active lines */
+    sethvalue(L, L->top, t);  /* push it on stack */
+    api_incr_top(L);
+    setbvalue(&v, 1);  /* boolean 'true' to be the value of all indices */
+    for (i = 0; i < f->l.p->sizelineinfo; i++)  /* for all lines with code */
+      luaH_setint(L, t, lineinfo[i], &v);  /* table[line] = true */
+  }
+}
+
+
+static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
+                       Closure *f, CallInfo *ci) {
+  int status = 1;
+  for (; *what; what++) {
+    switch (*what) {
+      case 'S': {
+        funcinfo(ar, f);
+        break;
+      }
+      case 'l': {
+        ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
+        break;
+      }
+      case 'u': {
+        ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
+        if (noLuaClosure(f)) {
+          ar->isvararg = 1;
+          ar->nparams = 0;
+        }
+        else {
+          ar->isvararg = f->l.p->is_vararg;
+          ar->nparams = f->l.p->numparams;
+        }
+        break;
+      }
+      case 't': {
+        ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
+        break;
+      }
+      case 'n': {
+        /* calling function is a known Lua function? */
+        if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
+          ar->namewhat = getfuncname(L, ci->previous, &ar->name);
+        else
+          ar->namewhat = NULL;
+        if (ar->namewhat == NULL) {
+          ar->namewhat = "";  /* not found */
+          ar->name = NULL;
+        }
+        break;
+      }
+      case 'L':
+      case 'f':  /* handled by lua_getinfo */
+        break;
+      default: status = 0;  /* invalid option */
+    }
+  }
+  return status;
+}
+
+
+LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
+  int status;
+  Closure *cl;
+  CallInfo *ci;
+  StkId func;
+  lua_lock(L);
+  swapextra(L);
+  if (*what == '>') {
+    ci = NULL;
+    func = L->top - 1;
+    api_check(L, ttisfunction(func), "function expected");
+    what++;  /* skip the '>' */
+    L->top--;  /* pop function */
+  }
+  else {
+    ci = ar->i_ci;
+    func = ci->func;
+    lua_assert(ttisfunction(ci->func));
+  }
+  cl = ttisclosure(func) ? clvalue(func) : NULL;
+  status = auxgetinfo(L, what, ar, cl, ci);
+  if (strchr(what, 'f')) {
+    setobjs2s(L, L->top, func);
+    api_incr_top(L);
+  }
+  swapextra(L);  /* correct before option 'L', which can raise a mem. error */
+  if (strchr(what, 'L'))
+    collectvalidlines(L, cl);
+  lua_unlock(L);
+  return status;
+}
+
+
+/*
+** {======================================================
+** Symbolic Execution
+** =======================================================
+*/
+
+static const char *getobjname (Proto *p, int lastpc, int reg,
+                               const char **name);
+
+
+/*
+** find a "name" for the RK value 'c'
+*/
+static void kname (Proto *p, int pc, int c, const char **name) {
+  if (ISK(c)) {  /* is 'c' a constant? */
+    TValue *kvalue = &p->k[INDEXK(c)];
+    if (ttisstring(kvalue)) {  /* literal constant? */
+      *name = svalue(kvalue);  /* it is its own name */
+      return;
+    }
+    /* else no reasonable name found */
+  }
+  else {  /* 'c' is a register */
+    const char *what = getobjname(p, pc, c, name); /* search for 'c' */
+    if (what && *what == 'c') {  /* found a constant name? */
+      return;  /* 'name' already filled */
+    }
+    /* else no reasonable name found */
+  }
+  *name = "?";  /* no reasonable name found */
+}
+
+
+static int filterpc (int pc, int jmptarget) {
+  if (pc < jmptarget)  /* is code conditional (inside a jump)? */
+    return -1;  /* cannot know who sets that register */
+  else return pc;  /* current position sets that register */
+}
+
+
+/*
+** try to find last instruction before 'lastpc' that modified register 'reg'
+*/
+static int findsetreg (Proto *p, int lastpc, int reg) {
+  int pc;
+  int setreg = -1;  /* keep last instruction that changed 'reg' */
+  int jmptarget = 0;  /* any code before this address is conditional */
+  for (pc = 0; pc < lastpc; pc++) {
+    Instruction i = p->code[pc];
+    OpCode op = GET_OPCODE(i);
+    int a = GETARG_A(i);
+    switch (op) {
+      case OP_LOADNIL: {
+        int b = GETARG_B(i);
+        if (a <= reg && reg <= a + b)  /* set registers from 'a' to 'a+b' */
+          setreg = filterpc(pc, jmptarget);
+        break;
+      }
+      case OP_TFORCALL: {
+        if (reg >= a + 2)  /* affect all regs above its base */
+          setreg = filterpc(pc, jmptarget);
+        break;
+      }
+      case OP_CALL:
+      case OP_TAILCALL: {
+        if (reg >= a)  /* affect all registers above base */
+          setreg = filterpc(pc, jmptarget);
+        break;
+      }
+      case OP_JMP: {
+        int b = GETARG_sBx(i);
+        int dest = pc + 1 + b;
+        /* jump is forward and do not skip 'lastpc'? */
+        if (pc < dest && dest <= lastpc) {
+          if (dest > jmptarget)
+            jmptarget = dest;  /* update 'jmptarget' */
+        }
+        break;
+      }
+      default:
+        if (testAMode(op) && reg == a)  /* any instruction that set A */
+          setreg = filterpc(pc, jmptarget);
+        break;
+    }
+  }
+  return setreg;
+}
+
+
+static const char *getobjname (Proto *p, int lastpc, int reg,
+                               const char **name) {
+  int pc;
+  *name = luaF_getlocalname(p, reg + 1, lastpc);
+  if (*name)  /* is a local? */
+    return "local";
+  /* else try symbolic execution */
+  pc = findsetreg(p, lastpc, reg);
+  if (pc != -1) {  /* could find instruction? */
+    Instruction i = p->code[pc];
+    OpCode op = GET_OPCODE(i);
+    switch (op) {
+      case OP_MOVE: {
+        int b = GETARG_B(i);  /* move from 'b' to 'a' */
+        if (b < GETARG_A(i))
+          return getobjname(p, pc, b, name);  /* get name for 'b' */
+        break;
+      }
+      case OP_GETTABUP:
+      case OP_GETTABLE: {
+        int k = GETARG_C(i);  /* key index */
+        int t = GETARG_B(i);  /* table index */
+        const char *vn = (op == OP_GETTABLE)  /* name of indexed variable */
+                         ? luaF_getlocalname(p, t + 1, pc)
+                         : upvalname(p, t);
+        kname(p, pc, k, name);
+        return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
+      }
+      case OP_GETUPVAL: {
+        *name = upvalname(p, GETARG_B(i));
+        return "upvalue";
+      }
+      case OP_LOADK:
+      case OP_LOADKX: {
+        int b = (op == OP_LOADK) ? GETARG_Bx(i)
+                                 : GETARG_Ax(p->code[pc + 1]);
+        if (ttisstring(&p->k[b])) {
+          *name = svalue(&p->k[b]);
+          return "constant";
+        }
+        break;
+      }
+      case OP_SELF: {
+        int k = GETARG_C(i);  /* key index */
+        kname(p, pc, k, name);
+        return "method";
+      }
+      default: break;  /* go through to return NULL */
+    }
+  }
+  return NULL;  /* could not find reasonable name */
+}
+
+
+static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
+  TMS tm = (TMS)0;  /* to avoid warnings */
+  Proto *p = ci_func(ci)->p;  /* calling function */
+  int pc = currentpc(ci);  /* calling instruction index */
+  Instruction i = p->code[pc];  /* calling instruction */
+  if (ci->callstatus & CIST_HOOKED) {  /* was it called inside a hook? */
+    *name = "?";
+    return "hook";
+  }
+  switch (GET_OPCODE(i)) {
+    case OP_CALL:
+    case OP_TAILCALL:  /* get function name */
+      return getobjname(p, pc, GETARG_A(i), name);
+    case OP_TFORCALL: {  /* for iterator */
+      *name = "for iterator";
+       return "for iterator";
+    }
+    /* all other instructions can call only through metamethods */
+    case OP_SELF: case OP_GETTABUP: case OP_GETTABLE:
+      tm = TM_INDEX;
+      break;
+    case OP_SETTABUP: case OP_SETTABLE:
+      tm = TM_NEWINDEX;
+      break;
+    case OP_ADD: case OP_SUB: case OP_MUL: case OP_MOD:
+    case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND:
+    case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: {
+      int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD);  /* ORDER OP */
+      tm = cast(TMS, offset + cast_int(TM_ADD));  /* ORDER TM */
+      break;
+    }
+    case OP_UNM: tm = TM_UNM; break;
+    case OP_BNOT: tm = TM_BNOT; break;
+    case OP_LEN: tm = TM_LEN; break;
+    case OP_CONCAT: tm = TM_CONCAT; break;
+    case OP_EQ: tm = TM_EQ; break;
+    case OP_LT: tm = TM_LT; break;
+    case OP_LE: tm = TM_LE; break;
+    default: lua_assert(0);  /* other instructions cannot call a function */
+  }
+  *name = getstr(G(L)->tmname[tm]);
+  return "metamethod";
+}
+
+/* }====================================================== */
+
+
+
+/*
+** The subtraction of two potentially unrelated pointers is
+** not ISO C, but it should not crash a program; the subsequent
+** checks are ISO C and ensure a correct result.
+*/
+static int isinstack (CallInfo *ci, const TValue *o) {
+  ptrdiff_t i = o - ci->u.l.base;
+  return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o);
+}
+
+
+/*
+** Checks whether value 'o' came from an upvalue. (That can only happen
+** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on
+** upvalues.)
+*/
+static const char *getupvalname (CallInfo *ci, const TValue *o,
+                                 const char **name) {
+  LClosure *c = ci_func(ci);
+  int i;
+  for (i = 0; i < c->nupvalues; i++) {
+    if (c->upvals[i]->v == o) {
+      *name = upvalname(c->p, i);
+      return "upvalue";
+    }
+  }
+  return NULL;
+}
+
+
+static const char *varinfo (lua_State *L, const TValue *o) {
+  const char *name = NULL;  /* to avoid warnings */
+  CallInfo *ci = L->ci;
+  const char *kind = NULL;
+  if (isLua(ci)) {
+    kind = getupvalname(ci, o, &name);  /* check whether 'o' is an upvalue */
+    if (!kind && isinstack(ci, o))  /* no? try a register */
+      kind = getobjname(ci_func(ci)->p, currentpc(ci),
+                        cast_int(o - ci->u.l.base), &name);
+  }
+  return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : "";
+}
+
+
+l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
+  const char *t = luaT_objtypename(L, o);
+  luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o));
+}
+
+
+l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
+  if (ttisstring(p1) || cvt2str(p1)) p1 = p2;
+  luaG_typeerror(L, p1, "concatenate");
+}
+
+
+l_noret luaG_opinterror (lua_State *L, const TValue *p1,
+                         const TValue *p2, const char *msg) {
+  lua_Number temp;
+  if (!tonumber(p1, &temp))  /* first operand is wrong? */
+    p2 = p1;  /* now second is wrong */
+  luaG_typeerror(L, p2, msg);
+}
+
+
+/*
+** Error when both values are convertible to numbers, but not to integers
+*/
+l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
+  lua_Integer temp;
+  if (!tointeger(p1, &temp))
+    p2 = p1;
+  luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
+}
+
+
+l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
+  const char *t1 = luaT_objtypename(L, p1);
+  const char *t2 = luaT_objtypename(L, p2);
+  if (strcmp(t1, t2) == 0)
+    luaG_runerror(L, "attempt to compare two %s values", t1);
+  else
+    luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
+}
+
+
+/* add src:line information to 'msg' */
+const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
+                                        int line) {
+  char buff[LUA_IDSIZE];
+  if (src)
+    luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
+  else {  /* no source available; use "?" instead */
+    buff[0] = '?'; buff[1] = '\0';
+  }
+  return luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
+}
+
+
+l_noret luaG_errormsg (lua_State *L) {
+  if (L->errfunc != 0) {  /* is there an error handling function? */
+    StkId errfunc = restorestack(L, L->errfunc);
+    setobjs2s(L, L->top, L->top - 1);  /* move argument */
+    setobjs2s(L, L->top - 1, errfunc);  /* push function */
+    L->top++;  /* assume EXTRA_STACK */
+    luaD_callnoyield(L, L->top - 2, 1);  /* call it */
+  }
+  luaD_throw(L, LUA_ERRRUN);
+}
+
+
+l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
+  CallInfo *ci = L->ci;
+  const char *msg;
+  va_list argp;
+  va_start(argp, fmt);
+  msg = luaO_pushvfstring(L, fmt, argp);  /* format message */
+  va_end(argp);
+  if (isLua(ci))  /* if Lua function, add source:line information */
+    luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci));
+  luaG_errormsg(L);
+}
+
+
+void luaG_traceexec (lua_State *L) {
+  CallInfo *ci = L->ci;
+  lu_byte mask = L->hookmask;
+  int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
+  if (counthook)
+    resethookcount(L);  /* reset count */
+  else if (!(mask & LUA_MASKLINE))
+    return;  /* no line hook and count != 0; nothing to be done */
+  if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
+    ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
+    return;  /* do not call hook again (VM yielded, so it did not move) */
+  }
+  if (counthook)
+    luaD_hook(L, LUA_HOOKCOUNT, -1);  /* call count hook */
+  if (mask & LUA_MASKLINE) {
+    Proto *p = ci_func(ci)->p;
+    int npc = pcRel(ci->u.l.savedpc, p);
+    int newline = getfuncline(p, npc);
+    if (npc == 0 ||  /* call linehook when enter a new function, */
+        ci->u.l.savedpc <= L->oldpc ||  /* when jump back (loop), or when */
+        newline != getfuncline(p, pcRel(L->oldpc, p)))  /* enter a new line */
+      luaD_hook(L, LUA_HOOKLINE, newline);  /* call line hook */
+  }
+  L->oldpc = ci->u.l.savedpc;
+  if (L->status == LUA_YIELD) {  /* did hook yield? */
+    if (counthook)
+      L->hookcount = 1;  /* undo decrement to zero */
+    ci->u.l.savedpc--;  /* undo increment (resume will increment it again) */
+    ci->callstatus |= CIST_HOOKYIELD;  /* mark that it yielded */
+    ci->func = L->top - 1;  /* protect stack below results */
+    luaD_throw(L, LUA_YIELD);
+  }
+}
+
diff --git a/src/ldebug.h b/src/ldebug.h
new file mode 100644
index 0000000..0e31546
--- /dev/null
+++ b/src/ldebug.h
@@ -0,0 +1,39 @@
+/*
+** $Id: ldebug.h,v 2.14 2015/05/22 17:45:56 roberto Exp $
+** Auxiliary functions from Debug Interface module
+** See Copyright Notice in lua.h
+*/
+
+#ifndef ldebug_h
+#define ldebug_h
+
+
+#include "lstate.h"
+
+
+#define pcRel(pc, p)	(cast(int, (pc) - (p)->code) - 1)
+
+#define getfuncline(f,pc)	(((f)->lineinfo) ? (f)->lineinfo[pc] : -1)
+
+#define resethookcount(L)	(L->hookcount = L->basehookcount)
+
+
+LUAI_FUNC l_noret luaG_typeerror (lua_State *L, const TValue *o,
+                                                const char *opname);
+LUAI_FUNC l_noret luaG_concaterror (lua_State *L, const TValue *p1,
+                                                  const TValue *p2);
+LUAI_FUNC l_noret luaG_opinterror (lua_State *L, const TValue *p1,
+                                                 const TValue *p2,
+                                                 const char *msg);
+LUAI_FUNC l_noret luaG_tointerror (lua_State *L, const TValue *p1,
+                                                 const TValue *p2);
+LUAI_FUNC l_noret luaG_ordererror (lua_State *L, const TValue *p1,
+                                                 const TValue *p2);
+LUAI_FUNC l_noret luaG_runerror (lua_State *L, const char *fmt, ...);
+LUAI_FUNC const char *luaG_addinfo (lua_State *L, const char *msg,
+                                                  TString *src, int line);
+LUAI_FUNC l_noret luaG_errormsg (lua_State *L);
+LUAI_FUNC void luaG_traceexec (lua_State *L);
+
+
+#endif
diff --git a/src/ldo.c b/src/ldo.c
new file mode 100644
index 0000000..8804c99
--- /dev/null
+++ b/src/ldo.c
@@ -0,0 +1,800 @@
+/*
+** $Id: ldo.c,v 2.151 2015/12/16 16:40:07 roberto Exp $
+** Stack and Call structure of Lua
+** See Copyright Notice in lua.h
+*/
+
+#define ldo_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <setjmp.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lapi.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lparser.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lundump.h"
+#include "lvm.h"
+#include "lzio.h"
+
+
+
+#define errorstatus(s)	((s) > LUA_YIELD)
+
+
+/*
+** {======================================================
+** Error-recovery functions
+** =======================================================
+*/
+
+/*
+** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By
+** default, Lua handles errors with exceptions when compiling as
+** C++ code, with _longjmp/_setjmp when asked to use them, and with
+** longjmp/setjmp otherwise.
+*/
+#if !defined(LUAI_THROW)				/* { */
+
+#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP)	/* { */
+
+/* C++ exceptions */
+#define LUAI_THROW(L,c)		throw(c)
+#define LUAI_TRY(L,c,a) \
+	try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; }
+#define luai_jmpbuf		int  /* dummy variable */
+
+#elif defined(LUA_USE_POSIX)				/* }{ */
+
+/* in POSIX, try _longjmp/_setjmp (more efficient) */
+#define LUAI_THROW(L,c)		_longjmp((c)->b, 1)
+#define LUAI_TRY(L,c,a)		if (_setjmp((c)->b) == 0) { a }
+#define luai_jmpbuf		jmp_buf
+
+#else							/* }{ */
+
+/* ISO C handling with long jumps */
+#define LUAI_THROW(L,c)		longjmp((c)->b, 1)
+#define LUAI_TRY(L,c,a)		if (setjmp((c)->b) == 0) { a }
+#define luai_jmpbuf		jmp_buf
+
+#endif							/* } */
+
+#endif							/* } */
+
+
+
+/* chain list of long jump buffers */
+struct lua_longjmp {
+  struct lua_longjmp *previous;
+  luai_jmpbuf b;
+  volatile int status;  /* error code */
+};
+
+
+static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
+  switch (errcode) {
+    case LUA_ERRMEM: {  /* memory error? */
+      setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */
+      break;
+    }
+    case LUA_ERRERR: {
+      setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
+      break;
+    }
+    default: {
+      setobjs2s(L, oldtop, L->top - 1);  /* error message on current top */
+      break;
+    }
+  }
+  L->top = oldtop + 1;
+}
+
+
+l_noret luaD_throw (lua_State *L, int errcode) {
+  if (L->errorJmp) {  /* thread has an error handler? */
+    L->errorJmp->status = errcode;  /* set status */
+    LUAI_THROW(L, L->errorJmp);  /* jump to it */
+  }
+  else {  /* thread has no error handler */
+    global_State *g = G(L);
+    L->status = cast_byte(errcode);  /* mark it as dead */
+    if (g->mainthread->errorJmp) {  /* main thread has a handler? */
+      setobjs2s(L, g->mainthread->top++, L->top - 1);  /* copy error obj. */
+      luaD_throw(g->mainthread, errcode);  /* re-throw in main thread */
+    }
+    else {  /* no handler at all; abort */
+      if (g->panic) {  /* panic function? */
+        seterrorobj(L, errcode, L->top);  /* assume EXTRA_STACK */
+        if (L->ci->top < L->top)
+          L->ci->top = L->top;  /* pushing msg. can break this invariant */
+        lua_unlock(L);
+        g->panic(L);  /* call panic function (last chance to jump out) */
+      }
+      abort();
+    }
+  }
+}
+
+
+int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
+  unsigned short oldnCcalls = L->nCcalls;
+  struct lua_longjmp lj;
+  lj.status = LUA_OK;
+  lj.previous = L->errorJmp;  /* chain new error handler */
+  L->errorJmp = &lj;
+  LUAI_TRY(L, &lj,
+    (*f)(L, ud);
+  );
+  L->errorJmp = lj.previous;  /* restore old error handler */
+  L->nCcalls = oldnCcalls;
+  return lj.status;
+}
+
+/* }====================================================== */
+
+
+/*
+** {==================================================================
+** Stack reallocation
+** ===================================================================
+*/
+static void correctstack (lua_State *L, TValue *oldstack) {
+  CallInfo *ci;
+  UpVal *up;
+  L->top = (L->top - oldstack) + L->stack;
+  for (up = L->openupval; up != NULL; up = up->u.open.next)
+    up->v = (up->v - oldstack) + L->stack;
+  for (ci = L->ci; ci != NULL; ci = ci->previous) {
+    ci->top = (ci->top - oldstack) + L->stack;
+    ci->func = (ci->func - oldstack) + L->stack;
+    if (isLua(ci))
+      ci->u.l.base = (ci->u.l.base - oldstack) + L->stack;
+  }
+}
+
+
+/* some space for error handling */
+#define ERRORSTACKSIZE	(LUAI_MAXSTACK + 200)
+
+
+void luaD_reallocstack (lua_State *L, int newsize) {
+  TValue *oldstack = L->stack;
+  int lim = L->stacksize;
+  lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
+  lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK);
+  luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue);
+  for (; lim < newsize; lim++)
+    setnilvalue(L->stack + lim); /* erase new segment */
+  L->stacksize = newsize;
+  L->stack_last = L->stack + newsize - EXTRA_STACK;
+  correctstack(L, oldstack);
+}
+
+
+void luaD_growstack (lua_State *L, int n) {
+  int size = L->stacksize;
+  if (size > LUAI_MAXSTACK)  /* error after extra size? */
+    luaD_throw(L, LUA_ERRERR);
+  else {
+    int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK;
+    int newsize = 2 * size;
+    if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK;
+    if (newsize < needed) newsize = needed;
+    if (newsize > LUAI_MAXSTACK) {  /* stack overflow? */
+      luaD_reallocstack(L, ERRORSTACKSIZE);
+      luaG_runerror(L, "stack overflow");
+    }
+    else
+      luaD_reallocstack(L, newsize);
+  }
+}
+
+
+static int stackinuse (lua_State *L) {
+  CallInfo *ci;
+  StkId lim = L->top;
+  for (ci = L->ci; ci != NULL; ci = ci->previous) {
+    lua_assert(ci->top <= L->stack_last);
+    if (lim < ci->top) lim = ci->top;
+  }
+  return cast_int(lim - L->stack) + 1;  /* part of stack in use */
+}
+
+
+void luaD_shrinkstack (lua_State *L) {
+  int inuse = stackinuse(L);
+  int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
+  if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK;
+  if (L->stacksize > LUAI_MAXSTACK)  /* was handling stack overflow? */
+    luaE_freeCI(L);  /* free all CIs (list grew because of an error) */
+  else
+    luaE_shrinkCI(L);  /* shrink list */
+  if (inuse <= LUAI_MAXSTACK &&  /* not handling stack overflow? */
+      goodsize < L->stacksize)  /* trying to shrink? */
+    luaD_reallocstack(L, goodsize);  /* shrink it */
+  else
+    condmovestack(L,,);  /* don't change stack (change only for debugging) */
+}
+
+
+void luaD_inctop (lua_State *L) {
+  luaD_checkstack(L, 1);
+  L->top++;
+}
+
+/* }================================================================== */
+
+
+/*
+** Call a hook for the given event. Make sure there is a hook to be
+** called. (Both 'L->hook' and 'L->hookmask', which triggers this
+** function, can be changed asynchronously by signals.)
+*/
+void luaD_hook (lua_State *L, int event, int line) {
+  lua_Hook hook = L->hook;
+  if (hook && L->allowhook) {  /* make sure there is a hook */
+    CallInfo *ci = L->ci;
+    ptrdiff_t top = savestack(L, L->top);
+    ptrdiff_t ci_top = savestack(L, ci->top);
+    lua_Debug ar;
+    ar.event = event;
+    ar.currentline = line;
+    ar.i_ci = ci;
+    luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
+    ci->top = L->top + LUA_MINSTACK;
+    lua_assert(ci->top <= L->stack_last);
+    L->allowhook = 0;  /* cannot call hooks inside a hook */
+    ci->callstatus |= CIST_HOOKED;
+    lua_unlock(L);
+    (*hook)(L, &ar);
+    lua_lock(L);
+    lua_assert(!L->allowhook);
+    L->allowhook = 1;
+    ci->top = restorestack(L, ci_top);
+    L->top = restorestack(L, top);
+    ci->callstatus &= ~CIST_HOOKED;
+  }
+}
+
+
+static void callhook (lua_State *L, CallInfo *ci) {
+  int hook = LUA_HOOKCALL;
+  ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
+  if (isLua(ci->previous) &&
+      GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
+    ci->callstatus |= CIST_TAIL;
+    hook = LUA_HOOKTAILCALL;
+  }
+  luaD_hook(L, hook, -1);
+  ci->u.l.savedpc--;  /* correct 'pc' */
+}
+
+
+static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
+  int i;
+  int nfixargs = p->numparams;
+  StkId base, fixed;
+  /* move fixed parameters to final position */
+  fixed = L->top - actual;  /* first fixed argument */
+  base = L->top;  /* final position of first argument */
+  for (i = 0; i < nfixargs && i < actual; i++) {
+    setobjs2s(L, L->top++, fixed + i);
+    setnilvalue(fixed + i);  /* erase original copy (for GC) */
+  }
+  for (; i < nfixargs; i++)
+    setnilvalue(L->top++);  /* complete missing arguments */
+  return base;
+}
+
+
+/*
+** Check whether __call metafield of 'func' is a function. If so, put
+** it in stack below original 'func' so that 'luaD_precall' can call
+** it. Raise an error if __call metafield is not a function.
+*/
+static void tryfuncTM (lua_State *L, StkId func) {
+  const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL);
+  StkId p;
+  if (!ttisfunction(tm))
+    luaG_typeerror(L, func, "call");
+  /* Open a hole inside the stack at 'func' */
+  for (p = L->top; p > func; p--)
+    setobjs2s(L, p, p-1);
+  L->top++;  /* slot ensured by caller */
+  setobj2s(L, func, tm);  /* tag method is the new function to be called */
+}
+
+
+
+#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
+
+
+/* macro to check stack size, preserving 'p' */
+#define checkstackp(L,n,p)  \
+  luaD_checkstackaux(L, n, \
+    ptrdiff_t t__ = savestack(L, p);  /* save 'p' */ \
+    luaC_checkGC(L),  /* stack grow uses memory */ \
+    p = restorestack(L, t__))  /* 'pos' part: restore 'p' */
+
+
+/*
+** Prepares a function call: checks the stack, creates a new CallInfo
+** entry, fills in the relevant information, calls hook if needed.
+** If function is a C function, does the call, too. (Otherwise, leave
+** the execution ('luaV_execute') to the caller, to allow stackless
+** calls.) Returns true iff function has been executed (C function).
+*/
+int luaD_precall (lua_State *L, StkId func, int nresults) {
+  lua_CFunction f;
+  CallInfo *ci;
+  switch (ttype(func)) {
+    case LUA_TCCL:  /* C closure */
+      f = clCvalue(func)->f;
+      goto Cfunc;
+    case LUA_TLCF:  /* light C function */
+      f = fvalue(func);
+     Cfunc: {
+      int n;  /* number of returns */
+      checkstackp(L, LUA_MINSTACK, func);  /* ensure minimum stack size */
+      ci = next_ci(L);  /* now 'enter' new function */
+      ci->nresults = nresults;
+      ci->func = func;
+      ci->top = L->top + LUA_MINSTACK;
+      lua_assert(ci->top <= L->stack_last);
+      ci->callstatus = 0;
+      if (L->hookmask & LUA_MASKCALL)
+        luaD_hook(L, LUA_HOOKCALL, -1);
+      lua_unlock(L);
+      n = (*f)(L);  /* do the actual call */
+      lua_lock(L);
+      api_checknelems(L, n);
+      luaD_poscall(L, ci, L->top - n, n);
+      return 1;
+    }
+    case LUA_TLCL: {  /* Lua function: prepare its call */
+      StkId base;
+      Proto *p = clLvalue(func)->p;
+      int n = cast_int(L->top - func) - 1;  /* number of real arguments */
+      int fsize = p->maxstacksize;  /* frame size */
+      checkstackp(L, fsize, func);
+      if (p->is_vararg != 1) {  /* do not use vararg? */
+        for (; n < p->numparams; n++)
+          setnilvalue(L->top++);  /* complete missing arguments */
+        base = func + 1;
+      }
+      else
+        base = adjust_varargs(L, p, n);
+      ci = next_ci(L);  /* now 'enter' new function */
+      ci->nresults = nresults;
+      ci->func = func;
+      ci->u.l.base = base;
+      L->top = ci->top = base + fsize;
+      lua_assert(ci->top <= L->stack_last);
+      ci->u.l.savedpc = p->code;  /* starting point */
+      ci->callstatus = CIST_LUA;
+      if (L->hookmask & LUA_MASKCALL)
+        callhook(L, ci);
+      return 0;
+    }
+    default: {  /* not a function */
+      checkstackp(L, 1, func);  /* ensure space for metamethod */
+      tryfuncTM(L, func);  /* try to get '__call' metamethod */
+      return luaD_precall(L, func, nresults);  /* now it must be a function */
+    }
+  }
+}
+
+
+/*
+** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'.
+** Handle most typical cases (zero results for commands, one result for
+** expressions, multiple results for tail calls/single parameters)
+** separated.
+*/
+static int moveresults (lua_State *L, const TValue *firstResult, StkId res,
+                                      int nres, int wanted) {
+  switch (wanted) {  /* handle typical cases separately */
+    case 0: break;  /* nothing to move */
+    case 1: {  /* one result needed */
+      if (nres == 0)   /* no results? */
+        firstResult = luaO_nilobject;  /* adjust with nil */
+      setobjs2s(L, res, firstResult);  /* move it to proper place */
+      break;
+    }
+    case LUA_MULTRET: {
+      int i;
+      for (i = 0; i < nres; i++)  /* move all results to correct place */
+        setobjs2s(L, res + i, firstResult + i);
+      L->top = res + nres;
+      return 0;  /* wanted == LUA_MULTRET */
+    }
+    default: {
+      int i;
+      if (wanted <= nres) {  /* enough results? */
+        for (i = 0; i < wanted; i++)  /* move wanted results to correct place */
+          setobjs2s(L, res + i, firstResult + i);
+      }
+      else {  /* not enough results; use all of them plus nils */
+        for (i = 0; i < nres; i++)  /* move all results to correct place */
+          setobjs2s(L, res + i, firstResult + i);
+        for (; i < wanted; i++)  /* complete wanted number of results */
+          setnilvalue(res + i);
+      }
+      break;
+    }
+  }
+  L->top = res + wanted;  /* top points after the last result */
+  return 1;
+}
+
+
+/*
+** Finishes a function call: calls hook if necessary, removes CallInfo,
+** moves current number of results to proper place; returns 0 iff call
+** wanted multiple (variable number of) results.
+*/
+int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
+  StkId res;
+  int wanted = ci->nresults;
+  if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
+    if (L->hookmask & LUA_MASKRET) {
+      ptrdiff_t fr = savestack(L, firstResult);  /* hook may change stack */
+      luaD_hook(L, LUA_HOOKRET, -1);
+      firstResult = restorestack(L, fr);
+    }
+    L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
+  }
+  res = ci->func;  /* res == final position of 1st result */
+  L->ci = ci->previous;  /* back to caller */
+  /* move results to proper place */
+  return moveresults(L, firstResult, res, nres, wanted);
+}
+
+
+/*
+** Check appropriate error for stack overflow ("regular" overflow or
+** overflow while handling stack overflow). If 'nCalls' is larger than
+** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
+** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to
+** allow overflow handling to work)
+*/
+static void stackerror (lua_State *L) {
+  if (L->nCcalls == LUAI_MAXCCALLS)
+    luaG_runerror(L, "C stack overflow");
+  else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3)))
+    luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
+}
+
+
+/*
+** Call a function (C or Lua). The function to be called is at *func.
+** The arguments are on the stack, right after the function.
+** When returns, all the results are on the stack, starting at the original
+** function position.
+*/
+void luaD_call (lua_State *L, StkId func, int nResults) {
+  if (++L->nCcalls >= LUAI_MAXCCALLS)
+    stackerror(L);
+  if (!luaD_precall(L, func, nResults))  /* is a Lua function? */
+    luaV_execute(L);  /* call it */
+  L->nCcalls--;
+}
+
+
+/*
+** Similar to 'luaD_call', but does not allow yields during the call
+*/
+void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
+  L->nny++;
+  luaD_call(L, func, nResults);
+  L->nny--;
+}
+
+
+/*
+** Completes the execution of an interrupted C function, calling its
+** continuation function.
+*/
+static void finishCcall (lua_State *L, int status) {
+  CallInfo *ci = L->ci;
+  int n;
+  /* must have a continuation and must be able to call it */
+  lua_assert(ci->u.c.k != NULL && L->nny == 0);
+  /* error status can only happen in a protected call */
+  lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
+  if (ci->callstatus & CIST_YPCALL) {  /* was inside a pcall? */
+    ci->callstatus &= ~CIST_YPCALL;  /* finish 'lua_pcall' */
+    L->errfunc = ci->u.c.old_errfunc;
+  }
+  /* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already
+     handled */
+  adjustresults(L, ci->nresults);
+  /* call continuation function */
+  lua_unlock(L);
+  n = (*ci->u.c.k)(L, status, ci->u.c.ctx);
+  lua_lock(L);
+  api_checknelems(L, n);
+  /* finish 'luaD_precall' */
+  luaD_poscall(L, ci, L->top - n, n);
+}
+
+
+/*
+** Executes "full continuation" (everything in the stack) of a
+** previously interrupted coroutine until the stack is empty (or another
+** interruption long-jumps out of the loop). If the coroutine is
+** recovering from an error, 'ud' points to the error status, which must
+** be passed to the first continuation function (otherwise the default
+** status is LUA_YIELD).
+*/
+static void unroll (lua_State *L, void *ud) {
+  if (ud != NULL)  /* error status? */
+    finishCcall(L, *(int *)ud);  /* finish 'lua_pcallk' callee */
+  while (L->ci != &L->base_ci) {  /* something in the stack */
+    if (!isLua(L->ci))  /* C function? */
+      finishCcall(L, LUA_YIELD);  /* complete its execution */
+    else {  /* Lua function */
+      luaV_finishOp(L);  /* finish interrupted instruction */
+      luaV_execute(L);  /* execute down to higher C 'boundary' */
+    }
+  }
+}
+
+
+/*
+** Try to find a suspended protected call (a "recover point") for the
+** given thread.
+*/
+static CallInfo *findpcall (lua_State *L) {
+  CallInfo *ci;
+  for (ci = L->ci; ci != NULL; ci = ci->previous) {  /* search for a pcall */
+    if (ci->callstatus & CIST_YPCALL)
+      return ci;
+  }
+  return NULL;  /* no pending pcall */
+}
+
+
+/*
+** Recovers from an error in a coroutine. Finds a recover point (if
+** there is one) and completes the execution of the interrupted
+** 'luaD_pcall'. If there is no recover point, returns zero.
+*/
+static int recover (lua_State *L, int status) {
+  StkId oldtop;
+  CallInfo *ci = findpcall(L);
+  if (ci == NULL) return 0;  /* no recovery point */
+  /* "finish" luaD_pcall */
+  oldtop = restorestack(L, ci->extra);
+  luaF_close(L, oldtop);
+  seterrorobj(L, status, oldtop);
+  L->ci = ci;
+  L->allowhook = getoah(ci->callstatus);  /* restore original 'allowhook' */
+  L->nny = 0;  /* should be zero to be yieldable */
+  luaD_shrinkstack(L);
+  L->errfunc = ci->u.c.old_errfunc;
+  return 1;  /* continue running the coroutine */
+}
+
+
+/*
+** signal an error in the call to 'resume', not in the execution of the
+** coroutine itself. (Such errors should not be handled by any coroutine
+** error handler and should not kill the coroutine.)
+*/
+static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
+  L->top = firstArg;  /* remove args from the stack */
+  setsvalue2s(L, L->top, luaS_new(L, msg));  /* push error message */
+  api_incr_top(L);
+  luaD_throw(L, -1);  /* jump back to 'lua_resume' */
+}
+
+
+/*
+** Do the work for 'lua_resume' in protected mode. Most of the work
+** depends on the status of the coroutine: initial state, suspended
+** inside a hook, or regularly suspended (optionally with a continuation
+** function), plus erroneous cases: non-suspended coroutine or dead
+** coroutine.
+*/
+static void resume (lua_State *L, void *ud) {
+  int nCcalls = L->nCcalls;
+  int n = *(cast(int*, ud));  /* number of arguments */
+  StkId firstArg = L->top - n;  /* first argument */
+  CallInfo *ci = L->ci;
+  if (nCcalls >= LUAI_MAXCCALLS)
+    resume_error(L, "C stack overflow", firstArg);
+  if (L->status == LUA_OK) {  /* may be starting a coroutine */
+    if (ci != &L->base_ci)  /* not in base level? */
+      resume_error(L, "cannot resume non-suspended coroutine", firstArg);
+    /* coroutine is in base level; start running it */
+    if (!luaD_precall(L, firstArg - 1, LUA_MULTRET))  /* Lua function? */
+      luaV_execute(L);  /* call it */
+  }
+  else if (L->status != LUA_YIELD)
+    resume_error(L, "cannot resume dead coroutine", firstArg);
+  else {  /* resuming from previous yield */
+    L->status = LUA_OK;  /* mark that it is running (again) */
+    ci->func = restorestack(L, ci->extra);
+    if (isLua(ci))  /* yielded inside a hook? */
+      luaV_execute(L);  /* just continue running Lua code */
+    else {  /* 'common' yield */
+      if (ci->u.c.k != NULL) {  /* does it have a continuation function? */
+        lua_unlock(L);
+        n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */
+        lua_lock(L);
+        api_checknelems(L, n);
+        firstArg = L->top - n;  /* yield results come from continuation */
+      }
+      luaD_poscall(L, ci, firstArg, n);  /* finish 'luaD_precall' */
+    }
+    unroll(L, NULL);  /* run continuation */
+  }
+  lua_assert(nCcalls == L->nCcalls);
+}
+
+
+LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
+  int status;
+  unsigned short oldnny = L->nny;  /* save "number of non-yieldable" calls */
+  lua_lock(L);
+  luai_userstateresume(L, nargs);
+  L->nCcalls = (from) ? from->nCcalls + 1 : 1;
+  L->nny = 0;  /* allow yields */
+  api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
+  status = luaD_rawrunprotected(L, resume, &nargs);
+  if (status == -1)  /* error calling 'lua_resume'? */
+    status = LUA_ERRRUN;
+  else {  /* continue running after recoverable errors */
+    while (errorstatus(status) && recover(L, status)) {
+      /* unroll continuation */
+      status = luaD_rawrunprotected(L, unroll, &status);
+    }
+    if (errorstatus(status)) {  /* unrecoverable error? */
+      L->status = cast_byte(status);  /* mark thread as 'dead' */
+      seterrorobj(L, status, L->top);  /* push error message */
+      L->ci->top = L->top;
+    }
+    else lua_assert(status == L->status);  /* normal end or yield */
+  }
+  L->nny = oldnny;  /* restore 'nny' */
+  L->nCcalls--;
+  lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_isyieldable (lua_State *L) {
+  return (L->nny == 0);
+}
+
+
+LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
+                        lua_KFunction k) {
+  CallInfo *ci = L->ci;
+  luai_userstateyield(L, nresults);
+  lua_lock(L);
+  api_checknelems(L, nresults);
+  if (L->nny > 0) {
+    if (L != G(L)->mainthread)
+      luaG_runerror(L, "attempt to yield across a C-call boundary");
+    else
+      luaG_runerror(L, "attempt to yield from outside a coroutine");
+  }
+  L->status = LUA_YIELD;
+  ci->extra = savestack(L, ci->func);  /* save current 'func' */
+  if (isLua(ci)) {  /* inside a hook? */
+    api_check(L, k == NULL, "hooks cannot continue after yielding");
+  }
+  else {
+    if ((ci->u.c.k = k) != NULL)  /* is there a continuation? */
+      ci->u.c.ctx = ctx;  /* save context */
+    ci->func = L->top - nresults - 1;  /* protect stack below results */
+    luaD_throw(L, LUA_YIELD);
+  }
+  lua_assert(ci->callstatus & CIST_HOOKED);  /* must be inside a hook */
+  lua_unlock(L);
+  return 0;  /* return to 'luaD_hook' */
+}
+
+
+int luaD_pcall (lua_State *L, Pfunc func, void *u,
+                ptrdiff_t old_top, ptrdiff_t ef) {
+  int status;
+  CallInfo *old_ci = L->ci;
+  lu_byte old_allowhooks = L->allowhook;
+  unsigned short old_nny = L->nny;
+  ptrdiff_t old_errfunc = L->errfunc;
+  L->errfunc = ef;
+  status = luaD_rawrunprotected(L, func, u);
+  if (status != LUA_OK) {  /* an error occurred? */
+    StkId oldtop = restorestack(L, old_top);
+    luaF_close(L, oldtop);  /* close possible pending closures */
+    seterrorobj(L, status, oldtop);
+    L->ci = old_ci;
+    L->allowhook = old_allowhooks;
+    L->nny = old_nny;
+    luaD_shrinkstack(L);
+  }
+  L->errfunc = old_errfunc;
+  return status;
+}
+
+
+
+/*
+** Execute a protected parser.
+*/
+struct SParser {  /* data to 'f_parser' */
+  ZIO *z;
+  Mbuffer buff;  /* dynamic structure used by the scanner */
+  Dyndata dyd;  /* dynamic structures used by the parser */
+  const char *mode;
+  const char *name;
+};
+
+
+static void checkmode (lua_State *L, const char *mode, const char *x) {
+  if (mode && strchr(mode, x[0]) == NULL) {
+    luaO_pushfstring(L,
+       "attempt to load a %s chunk (mode is '%s')", x, mode);
+    luaD_throw(L, LUA_ERRSYNTAX);
+  }
+}
+
+
+static void f_parser (lua_State *L, void *ud) {
+  LClosure *cl;
+  struct SParser *p = cast(struct SParser *, ud);
+  int c = zgetc(p->z);  /* read first character */
+  if (c == LUA_SIGNATURE[0]) {
+    checkmode(L, p->mode, "binary");
+    cl = luaU_undump(L, p->z, p->name);
+  }
+  else {
+    checkmode(L, p->mode, "text");
+    cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
+  }
+  lua_assert(cl->nupvalues == cl->p->sizeupvalues);
+  luaF_initupvals(L, cl);
+}
+
+
+int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
+                                        const char *mode) {
+  struct SParser p;
+  int status;
+  L->nny++;  /* cannot yield during parsing */
+  p.z = z; p.name = name; p.mode = mode;
+  p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0;
+  p.dyd.gt.arr = NULL; p.dyd.gt.size = 0;
+  p.dyd.label.arr = NULL; p.dyd.label.size = 0;
+  luaZ_initbuffer(L, &p.buff);
+  status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc);
+  luaZ_freebuffer(L, &p.buff);
+  luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size);
+  luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size);
+  luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size);
+  L->nny--;
+  return status;
+}
+
+
diff --git a/src/ldo.h b/src/ldo.h
new file mode 100644
index 0000000..4f5d51c
--- /dev/null
+++ b/src/ldo.h
@@ -0,0 +1,58 @@
+/*
+** $Id: ldo.h,v 2.29 2015/12/21 13:02:14 roberto Exp $
+** Stack and Call structure of Lua
+** See Copyright Notice in lua.h
+*/
+
+#ifndef ldo_h
+#define ldo_h
+
+
+#include "lobject.h"
+#include "lstate.h"
+#include "lzio.h"
+
+
+/*
+** Macro to check stack size and grow stack if needed.  Parameters
+** 'pre'/'pos' allow the macro to preserve a pointer into the
+** stack across reallocations, doing the work only when needed.
+** 'condmovestack' is used in heavy tests to force a stack reallocation
+** at every check.
+*/
+#define luaD_checkstackaux(L,n,pre,pos)  \
+	if (L->stack_last - L->top <= (n)) \
+	  { pre; luaD_growstack(L, n); pos; } else { condmovestack(L,pre,pos); }
+
+/* In general, 'pre'/'pos' are empty (nothing to save) */
+#define luaD_checkstack(L,n)	luaD_checkstackaux(L,n,(void)0,(void)0)
+
+
+
+#define savestack(L,p)		((char *)(p) - (char *)L->stack)
+#define restorestack(L,n)	((TValue *)((char *)L->stack + (n)))
+
+
+/* type of protected functions, to be ran by 'runprotected' */
+typedef void (*Pfunc) (lua_State *L, void *ud);
+
+LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
+                                                  const char *mode);
+LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
+LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults);
+LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
+LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
+LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u,
+                                        ptrdiff_t oldtop, ptrdiff_t ef);
+LUAI_FUNC int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult,
+                                          int nres);
+LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize);
+LUAI_FUNC void luaD_growstack (lua_State *L, int n);
+LUAI_FUNC void luaD_shrinkstack (lua_State *L);
+LUAI_FUNC void luaD_inctop (lua_State *L);
+
+LUAI_FUNC l_noret luaD_throw (lua_State *L, int errcode);
+LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
+
+#endif
+
diff --git a/src/ldump.c b/src/ldump.c
new file mode 100644
index 0000000..016e300
--- /dev/null
+++ b/src/ldump.c
@@ -0,0 +1,215 @@
+/*
+** $Id: ldump.c,v 2.37 2015/10/08 15:53:49 roberto Exp $
+** save precompiled Lua chunks
+** See Copyright Notice in lua.h
+*/
+
+#define ldump_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+
+#include "lua.h"
+
+#include "lobject.h"
+#include "lstate.h"
+#include "lundump.h"
+
+
+typedef struct {
+  lua_State *L;
+  lua_Writer writer;
+  void *data;
+  int strip;
+  int status;
+} DumpState;
+
+
+/*
+** All high-level dumps go through DumpVector; you can change it to
+** change the endianness of the result
+*/
+#define DumpVector(v,n,D)	DumpBlock(v,(n)*sizeof((v)[0]),D)
+
+#define DumpLiteral(s,D)	DumpBlock(s, sizeof(s) - sizeof(char), D)
+
+
+static void DumpBlock (const void *b, size_t size, DumpState *D) {
+  if (D->status == 0 && size > 0) {
+    lua_unlock(D->L);
+    D->status = (*D->writer)(D->L, b, size, D->data);
+    lua_lock(D->L);
+  }
+}
+
+
+#define DumpVar(x,D)		DumpVector(&x,1,D)
+
+
+static void DumpByte (int y, DumpState *D) {
+  lu_byte x = (lu_byte)y;
+  DumpVar(x, D);
+}
+
+
+static void DumpInt (int x, DumpState *D) {
+  DumpVar(x, D);
+}
+
+
+static void DumpNumber (lua_Number x, DumpState *D) {
+  DumpVar(x, D);
+}
+
+
+static void DumpInteger (lua_Integer x, DumpState *D) {
+  DumpVar(x, D);
+}
+
+
+static void DumpString (const TString *s, DumpState *D) {
+  if (s == NULL)
+    DumpByte(0, D);
+  else {
+    size_t size = tsslen(s) + 1;  /* include trailing '\0' */
+    const char *str = getstr(s);
+    if (size < 0xFF)
+      DumpByte(cast_int(size), D);
+    else {
+      DumpByte(0xFF, D);
+      DumpVar(size, D);
+    }
+    DumpVector(str, size - 1, D);  /* no need to save '\0' */
+  }
+}
+
+
+static void DumpCode (const Proto *f, DumpState *D) {
+  DumpInt(f->sizecode, D);
+  DumpVector(f->code, f->sizecode, D);
+}
+
+
+static void DumpFunction(const Proto *f, TString *psource, DumpState *D);
+
+static void DumpConstants (const Proto *f, DumpState *D) {
+  int i;
+  int n = f->sizek;
+  DumpInt(n, D);
+  for (i = 0; i < n; i++) {
+    const TValue *o = &f->k[i];
+    DumpByte(ttype(o), D);
+    switch (ttype(o)) {
+    case LUA_TNIL:
+      break;
+    case LUA_TBOOLEAN:
+      DumpByte(bvalue(o), D);
+      break;
+    case LUA_TNUMFLT:
+      DumpNumber(fltvalue(o), D);
+      break;
+    case LUA_TNUMINT:
+      DumpInteger(ivalue(o), D);
+      break;
+    case LUA_TSHRSTR:
+    case LUA_TLNGSTR:
+      DumpString(tsvalue(o), D);
+      break;
+    default:
+      lua_assert(0);
+    }
+  }
+}
+
+
+static void DumpProtos (const Proto *f, DumpState *D) {
+  int i;
+  int n = f->sizep;
+  DumpInt(n, D);
+  for (i = 0; i < n; i++)
+    DumpFunction(f->p[i], f->source, D);
+}
+
+
+static void DumpUpvalues (const Proto *f, DumpState *D) {
+  int i, n = f->sizeupvalues;
+  DumpInt(n, D);
+  for (i = 0; i < n; i++) {
+    DumpByte(f->upvalues[i].instack, D);
+    DumpByte(f->upvalues[i].idx, D);
+  }
+}
+
+
+static void DumpDebug (const Proto *f, DumpState *D) {
+  int i, n;
+  n = (D->strip) ? 0 : f->sizelineinfo;
+  DumpInt(n, D);
+  DumpVector(f->lineinfo, n, D);
+  n = (D->strip) ? 0 : f->sizelocvars;
+  DumpInt(n, D);
+  for (i = 0; i < n; i++) {
+    DumpString(f->locvars[i].varname, D);
+    DumpInt(f->locvars[i].startpc, D);
+    DumpInt(f->locvars[i].endpc, D);
+  }
+  n = (D->strip) ? 0 : f->sizeupvalues;
+  DumpInt(n, D);
+  for (i = 0; i < n; i++)
+    DumpString(f->upvalues[i].name, D);
+}
+
+
+static void DumpFunction (const Proto *f, TString *psource, DumpState *D) {
+  if (D->strip || f->source == psource)
+    DumpString(NULL, D);  /* no debug info or same source as its parent */
+  else
+    DumpString(f->source, D);
+  DumpInt(f->linedefined, D);
+  DumpInt(f->lastlinedefined, D);
+  DumpByte(f->numparams, D);
+  DumpByte(f->is_vararg, D);
+  DumpByte(f->maxstacksize, D);
+  DumpCode(f, D);
+  DumpConstants(f, D);
+  DumpUpvalues(f, D);
+  DumpProtos(f, D);
+  DumpDebug(f, D);
+}
+
+
+static void DumpHeader (DumpState *D) {
+  DumpLiteral(LUA_SIGNATURE, D);
+  DumpByte(LUAC_VERSION, D);
+  DumpByte(LUAC_FORMAT, D);
+  DumpLiteral(LUAC_DATA, D);
+  DumpByte(sizeof(int), D);
+  DumpByte(sizeof(size_t), D);
+  DumpByte(sizeof(Instruction), D);
+  DumpByte(sizeof(lua_Integer), D);
+  DumpByte(sizeof(lua_Number), D);
+  DumpInteger(LUAC_INT, D);
+  DumpNumber(LUAC_NUM, D);
+}
+
+
+/*
+** dump Lua function as precompiled chunk
+*/
+int luaU_dump(lua_State *L, const Proto *f, lua_Writer w, void *data,
+              int strip) {
+  DumpState D;
+  D.L = L;
+  D.writer = w;
+  D.data = data;
+  D.strip = strip;
+  D.status = 0;
+  DumpHeader(&D);
+  DumpByte(f->sizeupvalues, &D);
+  DumpFunction(f, NULL, &D);
+  return D.status;
+}
+
diff --git a/src/lfunc.c b/src/lfunc.c
new file mode 100644
index 0000000..67967da
--- /dev/null
+++ b/src/lfunc.c
@@ -0,0 +1,151 @@
+/*
+** $Id: lfunc.c,v 2.45 2014/11/02 19:19:04 roberto Exp $
+** Auxiliary functions to manipulate prototypes and closures
+** See Copyright Notice in lua.h
+*/
+
+#define lfunc_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+
+#include "lua.h"
+
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+
+
+
+CClosure *luaF_newCclosure (lua_State *L, int n) {
+  GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n));
+  CClosure *c = gco2ccl(o);
+  c->nupvalues = cast_byte(n);
+  return c;
+}
+
+
+LClosure *luaF_newLclosure (lua_State *L, int n) {
+  GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n));
+  LClosure *c = gco2lcl(o);
+  c->p = NULL;
+  c->nupvalues = cast_byte(n);
+  while (n--) c->upvals[n] = NULL;
+  return c;
+}
+
+/*
+** fill a closure with new closed upvalues
+*/
+void luaF_initupvals (lua_State *L, LClosure *cl) {
+  int i;
+  for (i = 0; i < cl->nupvalues; i++) {
+    UpVal *uv = luaM_new(L, UpVal);
+    uv->refcount = 1;
+    uv->v = &uv->u.value;  /* make it closed */
+    setnilvalue(uv->v);
+    cl->upvals[i] = uv;
+  }
+}
+
+
+UpVal *luaF_findupval (lua_State *L, StkId level) {
+  UpVal **pp = &L->openupval;
+  UpVal *p;
+  UpVal *uv;
+  lua_assert(isintwups(L) || L->openupval == NULL);
+  while (*pp != NULL && (p = *pp)->v >= level) {
+    lua_assert(upisopen(p));
+    if (p->v == level)  /* found a corresponding upvalue? */
+      return p;  /* return it */
+    pp = &p->u.open.next;
+  }
+  /* not found: create a new upvalue */
+  uv = luaM_new(L, UpVal);
+  uv->refcount = 0;
+  uv->u.open.next = *pp;  /* link it to list of open upvalues */
+  uv->u.open.touched = 1;
+  *pp = uv;
+  uv->v = level;  /* current value lives in the stack */
+  if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
+    L->twups = G(L)->twups;  /* link it to the list */
+    G(L)->twups = L;
+  }
+  return uv;
+}
+
+
+void luaF_close (lua_State *L, StkId level) {
+  UpVal *uv;
+  while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
+    lua_assert(upisopen(uv));
+    L->openupval = uv->u.open.next;  /* remove from 'open' list */
+    if (uv->refcount == 0)  /* no references? */
+      luaM_free(L, uv);  /* free upvalue */
+    else {
+      setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
+      uv->v = &uv->u.value;  /* now current value lives here */
+      luaC_upvalbarrier(L, uv);
+    }
+  }
+}
+
+
+Proto *luaF_newproto (lua_State *L) {
+  GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto));
+  Proto *f = gco2p(o);
+  f->k = NULL;
+  f->sizek = 0;
+  f->p = NULL;
+  f->sizep = 0;
+  f->code = NULL;
+  f->cache = NULL;
+  f->sizecode = 0;
+  f->lineinfo = NULL;
+  f->sizelineinfo = 0;
+  f->upvalues = NULL;
+  f->sizeupvalues = 0;
+  f->numparams = 0;
+  f->is_vararg = 0;
+  f->maxstacksize = 0;
+  f->locvars = NULL;
+  f->sizelocvars = 0;
+  f->linedefined = 0;
+  f->lastlinedefined = 0;
+  f->source = NULL;
+  return f;
+}
+
+
+void luaF_freeproto (lua_State *L, Proto *f) {
+  luaM_freearray(L, f->code, f->sizecode);
+  luaM_freearray(L, f->p, f->sizep);
+  luaM_freearray(L, f->k, f->sizek);
+  luaM_freearray(L, f->lineinfo, f->sizelineinfo);
+  luaM_freearray(L, f->locvars, f->sizelocvars);
+  luaM_freearray(L, f->upvalues, f->sizeupvalues);
+  luaM_free(L, f);
+}
+
+
+/*
+** Look for n-th local variable at line 'line' in function 'func'.
+** Returns NULL if not found.
+*/
+const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
+  int i;
+  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
+    if (pc < f->locvars[i].endpc) {  /* is variable active? */
+      local_number--;
+      if (local_number == 0)
+        return getstr(f->locvars[i].varname);
+    }
+  }
+  return NULL;  /* not found */
+}
+
diff --git a/src/lfunc.h b/src/lfunc.h
new file mode 100644
index 0000000..2eeb0d5
--- /dev/null
+++ b/src/lfunc.h
@@ -0,0 +1,61 @@
+/*
+** $Id: lfunc.h,v 2.15 2015/01/13 15:49:11 roberto Exp $
+** Auxiliary functions to manipulate prototypes and closures
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lfunc_h
+#define lfunc_h
+
+
+#include "lobject.h"
+
+
+#define sizeCclosure(n)	(cast(int, sizeof(CClosure)) + \
+                         cast(int, sizeof(TValue)*((n)-1)))
+
+#define sizeLclosure(n)	(cast(int, sizeof(LClosure)) + \
+                         cast(int, sizeof(TValue *)*((n)-1)))
+
+
+/* test whether thread is in 'twups' list */
+#define isintwups(L)	(L->twups != L)
+
+
+/*
+** maximum number of upvalues in a closure (both C and Lua). (Value
+** must fit in a VM register.)
+*/
+#define MAXUPVAL	255
+
+
+/*
+** Upvalues for Lua closures
+*/
+struct UpVal {
+  TValue *v;  /* points to stack or to its own value */
+  lu_mem refcount;  /* reference counter */
+  union {
+    struct {  /* (when open) */
+      UpVal *next;  /* linked list */
+      int touched;  /* mark to avoid cycles with dead threads */
+    } open;
+    TValue value;  /* the value (when closed) */
+  } u;
+};
+
+#define upisopen(up)	((up)->v != &(up)->u.value)
+
+
+LUAI_FUNC Proto *luaF_newproto (lua_State *L);
+LUAI_FUNC CClosure *luaF_newCclosure (lua_State *L, int nelems);
+LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nelems);
+LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl);
+LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
+LUAI_FUNC void luaF_close (lua_State *L, StkId level);
+LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
+LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
+                                         int pc);
+
+
+#endif
diff --git a/src/lgc.c b/src/lgc.c
new file mode 100644
index 0000000..7c29fb0
--- /dev/null
+++ b/src/lgc.c
@@ -0,0 +1,1176 @@
+/*
+** $Id: lgc.c,v 2.212 2016/03/31 19:02:03 roberto Exp $
+** Garbage Collector
+** See Copyright Notice in lua.h
+*/
+
+#define lgc_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+
+
+/*
+** internal state for collector while inside the atomic phase. The
+** collector should never be in this state while running regular code.
+*/
+#define GCSinsideatomic		(GCSpause + 1)
+
+/*
+** cost of sweeping one element (the size of a small object divided
+** by some adjust for the sweep speed)
+*/
+#define GCSWEEPCOST	((sizeof(TString) + 4) / 4)
+
+/* maximum number of elements to sweep in each single step */
+#define GCSWEEPMAX	(cast_int((GCSTEPSIZE / GCSWEEPCOST) / 4))
+
+/* cost of calling one finalizer */
+#define GCFINALIZECOST	GCSWEEPCOST
+
+
+/*
+** macro to adjust 'stepmul': 'stepmul' is actually used like
+** 'stepmul / STEPMULADJ' (value chosen by tests)
+*/
+#define STEPMULADJ		200
+
+
+/*
+** macro to adjust 'pause': 'pause' is actually used like
+** 'pause / PAUSEADJ' (value chosen by tests)
+*/
+#define PAUSEADJ		100
+
+
+/*
+** 'makewhite' erases all color bits then sets only the current white
+** bit
+*/
+#define maskcolors	(~(bitmask(BLACKBIT) | WHITEBITS))
+#define makewhite(g,x)	\
+ (x->marked = cast_byte((x->marked & maskcolors) | luaC_white(g)))
+
+#define white2gray(x)	resetbits(x->marked, WHITEBITS)
+#define black2gray(x)	resetbit(x->marked, BLACKBIT)
+
+
+#define valiswhite(x)   (iscollectable(x) && iswhite(gcvalue(x)))
+
+#define checkdeadkey(n)	lua_assert(!ttisdeadkey(gkey(n)) || ttisnil(gval(n)))
+
+
+#define checkconsistency(obj)  \
+  lua_longassert(!iscollectable(obj) || righttt(obj))
+
+
+#define markvalue(g,o) { checkconsistency(o); \
+  if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); }
+
+#define markobject(g,t)	{ if (iswhite(t)) reallymarkobject(g, obj2gco(t)); }
+
+/*
+** mark an object that can be NULL (either because it is really optional,
+** or it was stripped as debug info, or inside an uncompleted structure)
+*/
+#define markobjectN(g,t)	{ if (t) markobject(g,t); }
+
+static void reallymarkobject (global_State *g, GCObject *o);
+
+
+/*
+** {======================================================
+** Generic functions
+** =======================================================
+*/
+
+
+/*
+** one after last element in a hash array
+*/
+#define gnodelast(h)	gnode(h, cast(size_t, sizenode(h)))
+
+
+/*
+** link collectable object 'o' into list pointed by 'p'
+*/
+#define linkgclist(o,p)	((o)->gclist = (p), (p) = obj2gco(o))
+
+
+/*
+** If key is not marked, mark its entry as dead. This allows key to be
+** collected, but keeps its entry in the table.  A dead node is needed
+** when Lua looks up for a key (it may be part of a chain) and when
+** traversing a weak table (key might be removed from the table during
+** traversal). Other places never manipulate dead keys, because its
+** associated nil value is enough to signal that the entry is logically
+** empty.
+*/
+static void removeentry (Node *n) {
+  lua_assert(ttisnil(gval(n)));
+  if (valiswhite(gkey(n)))
+    setdeadvalue(wgkey(n));  /* unused and unmarked key; remove it */
+}
+
+
+/*
+** tells whether a key or value can be cleared from a weak
+** table. Non-collectable objects are never removed from weak
+** tables. Strings behave as 'values', so are never removed too. for
+** other objects: if really collected, cannot keep them; for objects
+** being finalized, keep them in keys, but not in values
+*/
+static int iscleared (global_State *g, const TValue *o) {
+  if (!iscollectable(o)) return 0;
+  else if (ttisstring(o)) {
+    markobject(g, tsvalue(o));  /* strings are 'values', so are never weak */
+    return 0;
+  }
+  else return iswhite(gcvalue(o));
+}
+
+
+/*
+** barrier that moves collector forward, that is, mark the white object
+** being pointed by a black object. (If in sweep phase, clear the black
+** object to white [sweep it] to avoid other barrier calls for this
+** same object.)
+*/
+void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
+  global_State *g = G(L);
+  lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
+  if (keepinvariant(g))  /* must keep invariant? */
+    reallymarkobject(g, v);  /* restore invariant */
+  else {  /* sweep phase */
+    lua_assert(issweepphase(g));
+    makewhite(g, o);  /* mark main obj. as white to avoid other barriers */
+  }
+}
+
+
+/*
+** barrier that moves collector backward, that is, mark the black object
+** pointing to a white object as gray again.
+*/
+void luaC_barrierback_ (lua_State *L, Table *t) {
+  global_State *g = G(L);
+  lua_assert(isblack(t) && !isdead(g, t));
+  black2gray(t);  /* make table gray (again) */
+  linkgclist(t, g->grayagain);
+}
+
+
+/*
+** barrier for assignments to closed upvalues. Because upvalues are
+** shared among closures, it is impossible to know the color of all
+** closures pointing to it. So, we assume that the object being assigned
+** must be marked.
+*/
+void luaC_upvalbarrier_ (lua_State *L, UpVal *uv) {
+  global_State *g = G(L);
+  GCObject *o = gcvalue(uv->v);
+  lua_assert(!upisopen(uv));  /* ensured by macro luaC_upvalbarrier */
+  if (keepinvariant(g))
+    markobject(g, o);
+}
+
+
+void luaC_fix (lua_State *L, GCObject *o) {
+  global_State *g = G(L);
+  lua_assert(g->allgc == o);  /* object must be 1st in 'allgc' list! */
+  white2gray(o);  /* they will be gray forever */
+  g->allgc = o->next;  /* remove object from 'allgc' list */
+  o->next = g->fixedgc;  /* link it to 'fixedgc' list */
+  g->fixedgc = o;
+}
+
+
+/*
+** create a new collectable object (with given type and size) and link
+** it to 'allgc' list.
+*/
+GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) {
+  global_State *g = G(L);
+  GCObject *o = cast(GCObject *, luaM_newobject(L, novariant(tt), sz));
+  o->marked = luaC_white(g);
+  o->tt = tt;
+  o->next = g->allgc;
+  g->allgc = o;
+  return o;
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** Mark functions
+** =======================================================
+*/
+
+
+/*
+** mark an object. Userdata, strings, and closed upvalues are visited
+** and turned black here. Other objects are marked gray and added
+** to appropriate list to be visited (and turned black) later. (Open
+** upvalues are already linked in 'headuv' list.)
+*/
+static void reallymarkobject (global_State *g, GCObject *o) {
+ reentry:
+  white2gray(o);
+  switch (o->tt) {
+    case LUA_TSHRSTR: {
+      gray2black(o);
+      g->GCmemtrav += sizelstring(gco2ts(o)->shrlen);
+      break;
+    }
+    case LUA_TLNGSTR: {
+      gray2black(o);
+      g->GCmemtrav += sizelstring(gco2ts(o)->u.lnglen);
+      break;
+    }
+    case LUA_TUSERDATA: {
+      TValue uvalue;
+      markobjectN(g, gco2u(o)->metatable);  /* mark its metatable */
+      gray2black(o);
+      g->GCmemtrav += sizeudata(gco2u(o));
+      getuservalue(g->mainthread, gco2u(o), &uvalue);
+      if (valiswhite(&uvalue)) {  /* markvalue(g, &uvalue); */
+        o = gcvalue(&uvalue);
+        goto reentry;
+      }
+      break;
+    }
+    case LUA_TLCL: {
+      linkgclist(gco2lcl(o), g->gray);
+      break;
+    }
+    case LUA_TCCL: {
+      linkgclist(gco2ccl(o), g->gray);
+      break;
+    }
+    case LUA_TTABLE: {
+      linkgclist(gco2t(o), g->gray);
+      break;
+    }
+    case LUA_TTHREAD: {
+      linkgclist(gco2th(o), g->gray);
+      break;
+    }
+    case LUA_TPROTO: {
+      linkgclist(gco2p(o), g->gray);
+      break;
+    }
+    default: lua_assert(0); break;
+  }
+}
+
+
+/*
+** mark metamethods for basic types
+*/
+static void markmt (global_State *g) {
+  int i;
+  for (i=0; i < LUA_NUMTAGS; i++)
+    markobjectN(g, g->mt[i]);
+}
+
+
+/*
+** mark all objects in list of being-finalized
+*/
+static void markbeingfnz (global_State *g) {
+  GCObject *o;
+  for (o = g->tobefnz; o != NULL; o = o->next)
+    markobject(g, o);
+}
+
+
+/*
+** Mark all values stored in marked open upvalues from non-marked threads.
+** (Values from marked threads were already marked when traversing the
+** thread.) Remove from the list threads that no longer have upvalues and
+** not-marked threads.
+*/
+static void remarkupvals (global_State *g) {
+  lua_State *thread;
+  lua_State **p = &g->twups;
+  while ((thread = *p) != NULL) {
+    lua_assert(!isblack(thread));  /* threads are never black */
+    if (isgray(thread) && thread->openupval != NULL)
+      p = &thread->twups;  /* keep marked thread with upvalues in the list */
+    else {  /* thread is not marked or without upvalues */
+      UpVal *uv;
+      *p = thread->twups;  /* remove thread from the list */
+      thread->twups = thread;  /* mark that it is out of list */
+      for (uv = thread->openupval; uv != NULL; uv = uv->u.open.next) {
+        if (uv->u.open.touched) {
+          markvalue(g, uv->v);  /* remark upvalue's value */
+          uv->u.open.touched = 0;
+        }
+      }
+    }
+  }
+}
+
+
+/*
+** mark root set and reset all gray lists, to start a new collection
+*/
+static void restartcollection (global_State *g) {
+  g->gray = g->grayagain = NULL;
+  g->weak = g->allweak = g->ephemeron = NULL;
+  markobject(g, g->mainthread);
+  markvalue(g, &g->l_registry);
+  markmt(g);
+  markbeingfnz(g);  /* mark any finalizing object left from previous cycle */
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Traverse functions
+** =======================================================
+*/
+
+/*
+** Traverse a table with weak values and link it to proper list. During
+** propagate phase, keep it in 'grayagain' list, to be revisited in the
+** atomic phase. In the atomic phase, if table has any white value,
+** put it in 'weak' list, to be cleared.
+*/
+static void traverseweakvalue (global_State *g, Table *h) {
+  Node *n, *limit = gnodelast(h);
+  /* if there is array part, assume it may have white values (it is not
+     worth traversing it now just to check) */
+  int hasclears = (h->sizearray > 0);
+  for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
+    checkdeadkey(n);
+    if (ttisnil(gval(n)))  /* entry is empty? */
+      removeentry(n);  /* remove it */
+    else {
+      lua_assert(!ttisnil(gkey(n)));
+      markvalue(g, gkey(n));  /* mark key */
+      if (!hasclears && iscleared(g, gval(n)))  /* is there a white value? */
+        hasclears = 1;  /* table will have to be cleared */
+    }
+  }
+  if (g->gcstate == GCSpropagate)
+    linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
+  else if (hasclears)
+    linkgclist(h, g->weak);  /* has to be cleared later */
+}
+
+
+/*
+** Traverse an ephemeron table and link it to proper list. Returns true
+** iff any object was marked during this traversal (which implies that
+** convergence has to continue). During propagation phase, keep table
+** in 'grayagain' list, to be visited again in the atomic phase. In
+** the atomic phase, if table has any white->white entry, it has to
+** be revisited during ephemeron convergence (as that key may turn
+** black). Otherwise, if it has any white key, table has to be cleared
+** (in the atomic phase).
+*/
+static int traverseephemeron (global_State *g, Table *h) {
+  int marked = 0;  /* true if an object is marked in this traversal */
+  int hasclears = 0;  /* true if table has white keys */
+  int hasww = 0;  /* true if table has entry "white-key -> white-value" */
+  Node *n, *limit = gnodelast(h);
+  unsigned int i;
+  /* traverse array part */
+  for (i = 0; i < h->sizearray; i++) {
+    if (valiswhite(&h->array[i])) {
+      marked = 1;
+      reallymarkobject(g, gcvalue(&h->array[i]));
+    }
+  }
+  /* traverse hash part */
+  for (n = gnode(h, 0); n < limit; n++) {
+    checkdeadkey(n);
+    if (ttisnil(gval(n)))  /* entry is empty? */
+      removeentry(n);  /* remove it */
+    else if (iscleared(g, gkey(n))) {  /* key is not marked (yet)? */
+      hasclears = 1;  /* table must be cleared */
+      if (valiswhite(gval(n)))  /* value not marked yet? */
+        hasww = 1;  /* white-white entry */
+    }
+    else if (valiswhite(gval(n))) {  /* value not marked yet? */
+      marked = 1;
+      reallymarkobject(g, gcvalue(gval(n)));  /* mark it now */
+    }
+  }
+  /* link table into proper list */
+  if (g->gcstate == GCSpropagate)
+    linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
+  else if (hasww)  /* table has white->white entries? */
+    linkgclist(h, g->ephemeron);  /* have to propagate again */
+  else if (hasclears)  /* table has white keys? */
+    linkgclist(h, g->allweak);  /* may have to clean white keys */
+  return marked;
+}
+
+
+static void traversestrongtable (global_State *g, Table *h) {
+  Node *n, *limit = gnodelast(h);
+  unsigned int i;
+  for (i = 0; i < h->sizearray; i++)  /* traverse array part */
+    markvalue(g, &h->array[i]);
+  for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
+    checkdeadkey(n);
+    if (ttisnil(gval(n)))  /* entry is empty? */
+      removeentry(n);  /* remove it */
+    else {
+      lua_assert(!ttisnil(gkey(n)));
+      markvalue(g, gkey(n));  /* mark key */
+      markvalue(g, gval(n));  /* mark value */
+    }
+  }
+}
+
+
+static lu_mem traversetable (global_State *g, Table *h) {
+  const char *weakkey, *weakvalue;
+  const TValue *mode = gfasttm(g, h->metatable, TM_MODE);
+  markobjectN(g, h->metatable);
+  if (mode && ttisstring(mode) &&  /* is there a weak mode? */
+      ((weakkey = strchr(svalue(mode), 'k')),
+       (weakvalue = strchr(svalue(mode), 'v')),
+       (weakkey || weakvalue))) {  /* is really weak? */
+    black2gray(h);  /* keep table gray */
+    if (!weakkey)  /* strong keys? */
+      traverseweakvalue(g, h);
+    else if (!weakvalue)  /* strong values? */
+      traverseephemeron(g, h);
+    else  /* all weak */
+      linkgclist(h, g->allweak);  /* nothing to traverse now */
+  }
+  else  /* not weak */
+    traversestrongtable(g, h);
+  return sizeof(Table) + sizeof(TValue) * h->sizearray +
+                         sizeof(Node) * cast(size_t, sizenode(h));
+}
+
+
+/*
+** Traverse a prototype. (While a prototype is being build, its
+** arrays can be larger than needed; the extra slots are filled with
+** NULL, so the use of 'markobjectN')
+*/
+static int traverseproto (global_State *g, Proto *f) {
+  int i;
+  if (f->cache && iswhite(f->cache))
+    f->cache = NULL;  /* allow cache to be collected */
+  markobjectN(g, f->source);
+  for (i = 0; i < f->sizek; i++)  /* mark literals */
+    markvalue(g, &f->k[i]);
+  for (i = 0; i < f->sizeupvalues; i++)  /* mark upvalue names */
+    markobjectN(g, f->upvalues[i].name);
+  for (i = 0; i < f->sizep; i++)  /* mark nested protos */
+    markobjectN(g, f->p[i]);
+  for (i = 0; i < f->sizelocvars; i++)  /* mark local-variable names */
+    markobjectN(g, f->locvars[i].varname);
+  return sizeof(Proto) + sizeof(Instruction) * f->sizecode +
+                         sizeof(Proto *) * f->sizep +
+                         sizeof(TValue) * f->sizek +
+                         sizeof(int) * f->sizelineinfo +
+                         sizeof(LocVar) * f->sizelocvars +
+                         sizeof(Upvaldesc) * f->sizeupvalues;
+}
+
+
+static lu_mem traverseCclosure (global_State *g, CClosure *cl) {
+  int i;
+  for (i = 0; i < cl->nupvalues; i++)  /* mark its upvalues */
+    markvalue(g, &cl->upvalue[i]);
+  return sizeCclosure(cl->nupvalues);
+}
+
+/*
+** open upvalues point to values in a thread, so those values should
+** be marked when the thread is traversed except in the atomic phase
+** (because then the value cannot be changed by the thread and the
+** thread may not be traversed again)
+*/
+static lu_mem traverseLclosure (global_State *g, LClosure *cl) {
+  int i;
+  markobjectN(g, cl->p);  /* mark its prototype */
+  for (i = 0; i < cl->nupvalues; i++) {  /* mark its upvalues */
+    UpVal *uv = cl->upvals[i];
+    if (uv != NULL) {
+      if (upisopen(uv) && g->gcstate != GCSinsideatomic)
+        uv->u.open.touched = 1;  /* can be marked in 'remarkupvals' */
+      else
+        markvalue(g, uv->v);
+    }
+  }
+  return sizeLclosure(cl->nupvalues);
+}
+
+
+static lu_mem traversethread (global_State *g, lua_State *th) {
+  StkId o = th->stack;
+  if (o == NULL)
+    return 1;  /* stack not completely built yet */
+  lua_assert(g->gcstate == GCSinsideatomic ||
+             th->openupval == NULL || isintwups(th));
+  for (; o < th->top; o++)  /* mark live elements in the stack */
+    markvalue(g, o);
+  if (g->gcstate == GCSinsideatomic) {  /* final traversal? */
+    StkId lim = th->stack + th->stacksize;  /* real end of stack */
+    for (; o < lim; o++)  /* clear not-marked stack slice */
+      setnilvalue(o);
+    /* 'remarkupvals' may have removed thread from 'twups' list */ 
+    if (!isintwups(th) && th->openupval != NULL) {
+      th->twups = g->twups;  /* link it back to the list */
+      g->twups = th;
+    }
+  }
+  else if (g->gckind != KGC_EMERGENCY)
+    luaD_shrinkstack(th); /* do not change stack in emergency cycle */
+  return (sizeof(lua_State) + sizeof(TValue) * th->stacksize +
+          sizeof(CallInfo) * th->nci);
+}
+
+
+/*
+** traverse one gray object, turning it to black (except for threads,
+** which are always gray).
+*/
+static void propagatemark (global_State *g) {
+  lu_mem size;
+  GCObject *o = g->gray;
+  lua_assert(isgray(o));
+  gray2black(o);
+  switch (o->tt) {
+    case LUA_TTABLE: {
+      Table *h = gco2t(o);
+      g->gray = h->gclist;  /* remove from 'gray' list */
+      size = traversetable(g, h);
+      break;
+    }
+    case LUA_TLCL: {
+      LClosure *cl = gco2lcl(o);
+      g->gray = cl->gclist;  /* remove from 'gray' list */
+      size = traverseLclosure(g, cl);
+      break;
+    }
+    case LUA_TCCL: {
+      CClosure *cl = gco2ccl(o);
+      g->gray = cl->gclist;  /* remove from 'gray' list */
+      size = traverseCclosure(g, cl);
+      break;
+    }
+    case LUA_TTHREAD: {
+      lua_State *th = gco2th(o);
+      g->gray = th->gclist;  /* remove from 'gray' list */
+      linkgclist(th, g->grayagain);  /* insert into 'grayagain' list */
+      black2gray(o);
+      size = traversethread(g, th);
+      break;
+    }
+    case LUA_TPROTO: {
+      Proto *p = gco2p(o);
+      g->gray = p->gclist;  /* remove from 'gray' list */
+      size = traverseproto(g, p);
+      break;
+    }
+    default: lua_assert(0); return;
+  }
+  g->GCmemtrav += size;
+}
+
+
+static void propagateall (global_State *g) {
+  while (g->gray) propagatemark(g);
+}
+
+
+static void convergeephemerons (global_State *g) {
+  int changed;
+  do {
+    GCObject *w;
+    GCObject *next = g->ephemeron;  /* get ephemeron list */
+    g->ephemeron = NULL;  /* tables may return to this list when traversed */
+    changed = 0;
+    while ((w = next) != NULL) {
+      next = gco2t(w)->gclist;
+      if (traverseephemeron(g, gco2t(w))) {  /* traverse marked some value? */
+        propagateall(g);  /* propagate changes */
+        changed = 1;  /* will have to revisit all ephemeron tables */
+      }
+    }
+  } while (changed);
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Sweep Functions
+** =======================================================
+*/
+
+
+/*
+** clear entries with unmarked keys from all weaktables in list 'l' up
+** to element 'f'
+*/
+static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
+  for (; l != f; l = gco2t(l)->gclist) {
+    Table *h = gco2t(l);
+    Node *n, *limit = gnodelast(h);
+    for (n = gnode(h, 0); n < limit; n++) {
+      if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
+        setnilvalue(gval(n));  /* remove value ... */
+        removeentry(n);  /* and remove entry from table */
+      }
+    }
+  }
+}
+
+
+/*
+** clear entries with unmarked values from all weaktables in list 'l' up
+** to element 'f'
+*/
+static void clearvalues (global_State *g, GCObject *l, GCObject *f) {
+  for (; l != f; l = gco2t(l)->gclist) {
+    Table *h = gco2t(l);
+    Node *n, *limit = gnodelast(h);
+    unsigned int i;
+    for (i = 0; i < h->sizearray; i++) {
+      TValue *o = &h->array[i];
+      if (iscleared(g, o))  /* value was collected? */
+        setnilvalue(o);  /* remove value */
+    }
+    for (n = gnode(h, 0); n < limit; n++) {
+      if (!ttisnil(gval(n)) && iscleared(g, gval(n))) {
+        setnilvalue(gval(n));  /* remove value ... */
+        removeentry(n);  /* and remove entry from table */
+      }
+    }
+  }
+}
+
+
+void luaC_upvdeccount (lua_State *L, UpVal *uv) {
+  lua_assert(uv->refcount > 0);
+  uv->refcount--;
+  if (uv->refcount == 0 && !upisopen(uv))
+    luaM_free(L, uv);
+}
+
+
+static void freeLclosure (lua_State *L, LClosure *cl) {
+  int i;
+  for (i = 0; i < cl->nupvalues; i++) {
+    UpVal *uv = cl->upvals[i];
+    if (uv)
+      luaC_upvdeccount(L, uv);
+  }
+  luaM_freemem(L, cl, sizeLclosure(cl->nupvalues));
+}
+
+
+static void freeobj (lua_State *L, GCObject *o) {
+  switch (o->tt) {
+    case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break;
+    case LUA_TLCL: {
+      freeLclosure(L, gco2lcl(o));
+      break;
+    }
+    case LUA_TCCL: {
+      luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues));
+      break;
+    }
+    case LUA_TTABLE: luaH_free(L, gco2t(o)); break;
+    case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break;
+    case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
+    case LUA_TSHRSTR:
+      luaS_remove(L, gco2ts(o));  /* remove it from hash table */
+      luaM_freemem(L, o, sizelstring(gco2ts(o)->shrlen));
+      break;
+    case LUA_TLNGSTR: {
+      luaM_freemem(L, o, sizelstring(gco2ts(o)->u.lnglen));
+      break;
+    }
+    default: lua_assert(0);
+  }
+}
+
+
+#define sweepwholelist(L,p)	sweeplist(L,p,MAX_LUMEM)
+static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count);
+
+
+/*
+** sweep at most 'count' elements from a list of GCObjects erasing dead
+** objects, where a dead object is one marked with the old (non current)
+** white; change all non-dead objects back to white, preparing for next
+** collection cycle. Return where to continue the traversal or NULL if
+** list is finished.
+*/
+static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
+  global_State *g = G(L);
+  int ow = otherwhite(g);
+  int white = luaC_white(g);  /* current white */
+  while (*p != NULL && count-- > 0) {
+    GCObject *curr = *p;
+    int marked = curr->marked;
+    if (isdeadm(ow, marked)) {  /* is 'curr' dead? */
+      *p = curr->next;  /* remove 'curr' from list */
+      freeobj(L, curr);  /* erase 'curr' */
+    }
+    else {  /* change mark to 'white' */
+      curr->marked = cast_byte((marked & maskcolors) | white);
+      p = &curr->next;  /* go to next element */
+    }
+  }
+  return (*p == NULL) ? NULL : p;
+}
+
+
+/*
+** sweep a list until a live object (or end of list)
+*/
+static GCObject **sweeptolive (lua_State *L, GCObject **p) {
+  GCObject **old = p;
+  do {
+    p = sweeplist(L, p, 1);
+  } while (p == old);
+  return p;
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Finalization
+** =======================================================
+*/
+
+/*
+** If possible, shrink string table
+*/
+static void checkSizes (lua_State *L, global_State *g) {
+  if (g->gckind != KGC_EMERGENCY) {
+    l_mem olddebt = g->GCdebt;
+    if (g->strt.nuse < g->strt.size / 4)  /* string table too big? */
+      luaS_resize(L, g->strt.size / 2);  /* shrink it a little */
+    g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
+  }
+}
+
+
+static GCObject *udata2finalize (global_State *g) {
+  GCObject *o = g->tobefnz;  /* get first element */
+  lua_assert(tofinalize(o));
+  g->tobefnz = o->next;  /* remove it from 'tobefnz' list */
+  o->next = g->allgc;  /* return it to 'allgc' list */
+  g->allgc = o;
+  resetbit(o->marked, FINALIZEDBIT);  /* object is "normal" again */
+  if (issweepphase(g))
+    makewhite(g, o);  /* "sweep" object */
+  return o;
+}
+
+
+static void dothecall (lua_State *L, void *ud) {
+  UNUSED(ud);
+  luaD_callnoyield(L, L->top - 2, 0);
+}
+
+
+static void GCTM (lua_State *L, int propagateerrors) {
+  global_State *g = G(L);
+  const TValue *tm;
+  TValue v;
+  setgcovalue(L, &v, udata2finalize(g));
+  tm = luaT_gettmbyobj(L, &v, TM_GC);
+  if (tm != NULL && ttisfunction(tm)) {  /* is there a finalizer? */
+    int status;
+    lu_byte oldah = L->allowhook;
+    int running  = g->gcrunning;
+    L->allowhook = 0;  /* stop debug hooks during GC metamethod */
+    g->gcrunning = 0;  /* avoid GC steps */
+    setobj2s(L, L->top, tm);  /* push finalizer... */
+    setobj2s(L, L->top + 1, &v);  /* ... and its argument */
+    L->top += 2;  /* and (next line) call the finalizer */
+    status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
+    L->allowhook = oldah;  /* restore hooks */
+    g->gcrunning = running;  /* restore state */
+    if (status != LUA_OK && propagateerrors) {  /* error while running __gc? */
+      if (status == LUA_ERRRUN) {  /* is there an error object? */
+        const char *msg = (ttisstring(L->top - 1))
+                            ? svalue(L->top - 1)
+                            : "no message";
+        luaO_pushfstring(L, "error in __gc metamethod (%s)", msg);
+        status = LUA_ERRGCMM;  /* error in __gc metamethod */
+      }
+      luaD_throw(L, status);  /* re-throw error */
+    }
+  }
+}
+
+
+/*
+** call a few (up to 'g->gcfinnum') finalizers
+*/
+static int runafewfinalizers (lua_State *L) {
+  global_State *g = G(L);
+  unsigned int i;
+  lua_assert(!g->tobefnz || g->gcfinnum > 0);
+  for (i = 0; g->tobefnz && i < g->gcfinnum; i++)
+    GCTM(L, 1);  /* call one finalizer */
+  g->gcfinnum = (!g->tobefnz) ? 0  /* nothing more to finalize? */
+                    : g->gcfinnum * 2;  /* else call a few more next time */
+  return i;
+}
+
+
+/*
+** call all pending finalizers
+*/
+static void callallpendingfinalizers (lua_State *L) {
+  global_State *g = G(L);
+  while (g->tobefnz)
+    GCTM(L, 0);
+}
+
+
+/*
+** find last 'next' field in list 'p' list (to add elements in its end)
+*/
+static GCObject **findlast (GCObject **p) {
+  while (*p != NULL)
+    p = &(*p)->next;
+  return p;
+}
+
+
+/*
+** move all unreachable objects (or 'all' objects) that need
+** finalization from list 'finobj' to list 'tobefnz' (to be finalized)
+*/
+static void separatetobefnz (global_State *g, int all) {
+  GCObject *curr;
+  GCObject **p = &g->finobj;
+  GCObject **lastnext = findlast(&g->tobefnz);
+  while ((curr = *p) != NULL) {  /* traverse all finalizable objects */
+    lua_assert(tofinalize(curr));
+    if (!(iswhite(curr) || all))  /* not being collected? */
+      p = &curr->next;  /* don't bother with it */
+    else {
+      *p = curr->next;  /* remove 'curr' from 'finobj' list */
+      curr->next = *lastnext;  /* link at the end of 'tobefnz' list */
+      *lastnext = curr;
+      lastnext = &curr->next;
+    }
+  }
+}
+
+
+/*
+** if object 'o' has a finalizer, remove it from 'allgc' list (must
+** search the list to find it) and link it in 'finobj' list.
+*/
+void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
+  global_State *g = G(L);
+  if (tofinalize(o) ||                 /* obj. is already marked... */
+      gfasttm(g, mt, TM_GC) == NULL)   /* or has no finalizer? */
+    return;  /* nothing to be done */
+  else {  /* move 'o' to 'finobj' list */
+    GCObject **p;
+    if (issweepphase(g)) {
+      makewhite(g, o);  /* "sweep" object 'o' */
+      if (g->sweepgc == &o->next)  /* should not remove 'sweepgc' object */
+        g->sweepgc = sweeptolive(L, g->sweepgc);  /* change 'sweepgc' */
+    }
+    /* search for pointer pointing to 'o' */
+    for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ }
+    *p = o->next;  /* remove 'o' from 'allgc' list */
+    o->next = g->finobj;  /* link it in 'finobj' list */
+    g->finobj = o;
+    l_setbit(o->marked, FINALIZEDBIT);  /* mark it as such */
+  }
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** GC control
+** =======================================================
+*/
+
+
+/*
+** Set a reasonable "time" to wait before starting a new GC cycle; cycle
+** will start when memory use hits threshold. (Division by 'estimate'
+** should be OK: it cannot be zero (because Lua cannot even start with
+** less than PAUSEADJ bytes).
+*/
+static void setpause (global_State *g) {
+  l_mem threshold, debt;
+  l_mem estimate = g->GCestimate / PAUSEADJ;  /* adjust 'estimate' */
+  lua_assert(estimate > 0);
+  threshold = (g->gcpause < MAX_LMEM / estimate)  /* overflow? */
+            ? estimate * g->gcpause  /* no overflow */
+            : MAX_LMEM;  /* overflow; truncate to maximum */
+  debt = gettotalbytes(g) - threshold;
+  luaE_setdebt(g, debt);
+}
+
+
+/*
+** Enter first sweep phase.
+** The call to 'sweeplist' tries to make pointer point to an object
+** inside the list (instead of to the header), so that the real sweep do
+** not need to skip objects created between "now" and the start of the
+** real sweep.
+*/
+static void entersweep (lua_State *L) {
+  global_State *g = G(L);
+  g->gcstate = GCSswpallgc;
+  lua_assert(g->sweepgc == NULL);
+  g->sweepgc = sweeplist(L, &g->allgc, 1);
+}
+
+
+void luaC_freeallobjects (lua_State *L) {
+  global_State *g = G(L);
+  separatetobefnz(g, 1);  /* separate all objects with finalizers */
+  lua_assert(g->finobj == NULL);
+  callallpendingfinalizers(L);
+  lua_assert(g->tobefnz == NULL);
+  g->currentwhite = WHITEBITS; /* this "white" makes all objects look dead */
+  g->gckind = KGC_NORMAL;
+  sweepwholelist(L, &g->finobj);
+  sweepwholelist(L, &g->allgc);
+  sweepwholelist(L, &g->fixedgc);  /* collect fixed objects */
+  lua_assert(g->strt.nuse == 0);
+}
+
+
+static l_mem atomic (lua_State *L) {
+  global_State *g = G(L);
+  l_mem work;
+  GCObject *origweak, *origall;
+  GCObject *grayagain = g->grayagain;  /* save original list */
+  lua_assert(g->ephemeron == NULL && g->weak == NULL);
+  lua_assert(!iswhite(g->mainthread));
+  g->gcstate = GCSinsideatomic;
+  g->GCmemtrav = 0;  /* start counting work */
+  markobject(g, L);  /* mark running thread */
+  /* registry and global metatables may be changed by API */
+  markvalue(g, &g->l_registry);
+  markmt(g);  /* mark global metatables */
+  /* remark occasional upvalues of (maybe) dead threads */
+  remarkupvals(g);
+  propagateall(g);  /* propagate changes */
+  work = g->GCmemtrav;  /* stop counting (do not recount 'grayagain') */
+  g->gray = grayagain;
+  propagateall(g);  /* traverse 'grayagain' list */
+  g->GCmemtrav = 0;  /* restart counting */
+  convergeephemerons(g);
+  /* at this point, all strongly accessible objects are marked. */
+  /* Clear values from weak tables, before checking finalizers */
+  clearvalues(g, g->weak, NULL);
+  clearvalues(g, g->allweak, NULL);
+  origweak = g->weak; origall = g->allweak;
+  work += g->GCmemtrav;  /* stop counting (objects being finalized) */
+  separatetobefnz(g, 0);  /* separate objects to be finalized */
+  g->gcfinnum = 1;  /* there may be objects to be finalized */
+  markbeingfnz(g);  /* mark objects that will be finalized */
+  propagateall(g);  /* remark, to propagate 'resurrection' */
+  g->GCmemtrav = 0;  /* restart counting */
+  convergeephemerons(g);
+  /* at this point, all resurrected objects are marked. */
+  /* remove dead objects from weak tables */
+  clearkeys(g, g->ephemeron, NULL);  /* clear keys from all ephemeron tables */
+  clearkeys(g, g->allweak, NULL);  /* clear keys from all 'allweak' tables */
+  /* clear values from resurrected weak tables */
+  clearvalues(g, g->weak, origweak);
+  clearvalues(g, g->allweak, origall);
+  luaS_clearcache(g);
+  g->currentwhite = cast_byte(otherwhite(g));  /* flip current white */
+  work += g->GCmemtrav;  /* complete counting */
+  return work;  /* estimate of memory marked by 'atomic' */
+}
+
+
+static lu_mem sweepstep (lua_State *L, global_State *g,
+                         int nextstate, GCObject **nextlist) {
+  if (g->sweepgc) {
+    l_mem olddebt = g->GCdebt;
+    g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
+    g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
+    if (g->sweepgc)  /* is there still something to sweep? */
+      return (GCSWEEPMAX * GCSWEEPCOST);
+  }
+  /* else enter next state */
+  g->gcstate = nextstate;
+  g->sweepgc = nextlist;
+  return 0;
+}
+
+
+static lu_mem singlestep (lua_State *L) {
+  global_State *g = G(L);
+  switch (g->gcstate) {
+    case GCSpause: {
+      g->GCmemtrav = g->strt.size * sizeof(GCObject*);
+      restartcollection(g);
+      g->gcstate = GCSpropagate;
+      return g->GCmemtrav;
+    }
+    case GCSpropagate: {
+      g->GCmemtrav = 0;
+      lua_assert(g->gray);
+      propagatemark(g);
+       if (g->gray == NULL)  /* no more gray objects? */
+        g->gcstate = GCSatomic;  /* finish propagate phase */
+      return g->GCmemtrav;  /* memory traversed in this step */
+    }
+    case GCSatomic: {
+      lu_mem work;
+      propagateall(g);  /* make sure gray list is empty */
+      work = atomic(L);  /* work is what was traversed by 'atomic' */
+      entersweep(L);
+      g->GCestimate = gettotalbytes(g);  /* first estimate */;
+      return work;
+    }
+    case GCSswpallgc: {  /* sweep "regular" objects */
+      return sweepstep(L, g, GCSswpfinobj, &g->finobj);
+    }
+    case GCSswpfinobj: {  /* sweep objects with finalizers */
+      return sweepstep(L, g, GCSswptobefnz, &g->tobefnz);
+    }
+    case GCSswptobefnz: {  /* sweep objects to be finalized */
+      return sweepstep(L, g, GCSswpend, NULL);
+    }
+    case GCSswpend: {  /* finish sweeps */
+      makewhite(g, g->mainthread);  /* sweep main thread */
+      checkSizes(L, g);
+      g->gcstate = GCScallfin;
+      return 0;
+    }
+    case GCScallfin: {  /* call remaining finalizers */
+      if (g->tobefnz && g->gckind != KGC_EMERGENCY) {
+        int n = runafewfinalizers(L);
+        return (n * GCFINALIZECOST);
+      }
+      else {  /* emergency mode or no more finalizers */
+        g->gcstate = GCSpause;  /* finish collection */
+        return 0;
+      }
+    }
+    default: lua_assert(0); return 0;
+  }
+}
+
+
+/*
+** advances the garbage collector until it reaches a state allowed
+** by 'statemask'
+*/
+void luaC_runtilstate (lua_State *L, int statesmask) {
+  global_State *g = G(L);
+  while (!testbit(statesmask, g->gcstate))
+    singlestep(L);
+}
+
+
+/*
+** get GC debt and convert it from Kb to 'work units' (avoid zero debt
+** and overflows)
+*/
+static l_mem getdebt (global_State *g) {
+  l_mem debt = g->GCdebt;
+  int stepmul = g->gcstepmul;
+  if (debt <= 0) return 0;  /* minimal debt */
+  else {
+    debt = (debt / STEPMULADJ) + 1;
+    debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
+    return debt;
+  }
+}
+
+/*
+** performs a basic GC step when collector is running
+*/
+void luaC_step (lua_State *L) {
+  global_State *g = G(L);
+  l_mem debt = getdebt(g);  /* GC deficit (be paid now) */
+  if (!g->gcrunning) {  /* not running? */
+    luaE_setdebt(g, -GCSTEPSIZE * 10);  /* avoid being called too often */
+    return;
+  }
+  do {  /* repeat until pause or enough "credit" (negative debt) */
+    lu_mem work = singlestep(L);  /* perform one single step */
+    debt -= work;
+  } while (debt > -GCSTEPSIZE && g->gcstate != GCSpause);
+  if (g->gcstate == GCSpause)
+    setpause(g);  /* pause until next cycle */
+  else {
+    debt = (debt / g->gcstepmul) * STEPMULADJ;  /* convert 'work units' to Kb */
+    luaE_setdebt(g, debt);
+    runafewfinalizers(L);
+  }
+}
+
+
+/*
+** Performs a full GC cycle; if 'isemergency', set a flag to avoid
+** some operations which could change the interpreter state in some
+** unexpected ways (running finalizers and shrinking some structures).
+** Before running the collection, check 'keepinvariant'; if it is true,
+** there may be some objects marked as black, so the collector has
+** to sweep all objects to turn them back to white (as white has not
+** changed, nothing will be collected).
+*/
+void luaC_fullgc (lua_State *L, int isemergency) {
+  global_State *g = G(L);
+  lua_assert(g->gckind == KGC_NORMAL);
+  if (isemergency) g->gckind = KGC_EMERGENCY;  /* set flag */
+  if (keepinvariant(g)) {  /* black objects? */
+    entersweep(L); /* sweep everything to turn them back to white */
+  }
+  /* finish any pending sweep phase to start a new cycle */
+  luaC_runtilstate(L, bitmask(GCSpause));
+  luaC_runtilstate(L, ~bitmask(GCSpause));  /* start new collection */
+  luaC_runtilstate(L, bitmask(GCScallfin));  /* run up to finalizers */
+  /* estimate must be correct after a full GC cycle */
+  lua_assert(g->GCestimate == gettotalbytes(g));
+  luaC_runtilstate(L, bitmask(GCSpause));  /* finish collection */
+  g->gckind = KGC_NORMAL;
+  setpause(g);
+}
+
+/* }====================================================== */
+
+
diff --git a/src/lgc.h b/src/lgc.h
new file mode 100644
index 0000000..aed3e18
--- /dev/null
+++ b/src/lgc.h
@@ -0,0 +1,147 @@
+/*
+** $Id: lgc.h,v 2.91 2015/12/21 13:02:14 roberto Exp $
+** Garbage Collector
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lgc_h
+#define lgc_h
+
+
+#include "lobject.h"
+#include "lstate.h"
+
+/*
+** Collectable objects may have one of three colors: white, which
+** means the object is not marked; gray, which means the
+** object is marked, but its references may be not marked; and
+** black, which means that the object and all its references are marked.
+** The main invariant of the garbage collector, while marking objects,
+** is that a black object can never point to a white one. Moreover,
+** any gray object must be in a "gray list" (gray, grayagain, weak,
+** allweak, ephemeron) so that it can be visited again before finishing
+** the collection cycle. These lists have no meaning when the invariant
+** is not being enforced (e.g., sweep phase).
+*/
+
+
+
+/* how much to allocate before next GC step */
+#if !defined(GCSTEPSIZE)
+/* ~100 small strings */
+#define GCSTEPSIZE	(cast_int(100 * sizeof(TString)))
+#endif
+
+
+/*
+** Possible states of the Garbage Collector
+*/
+#define GCSpropagate	0
+#define GCSatomic	1
+#define GCSswpallgc	2
+#define GCSswpfinobj	3
+#define GCSswptobefnz	4
+#define GCSswpend	5
+#define GCScallfin	6
+#define GCSpause	7
+
+
+#define issweepphase(g)  \
+	(GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend)
+
+
+/*
+** macro to tell when main invariant (white objects cannot point to black
+** ones) must be kept. During a collection, the sweep
+** phase may break the invariant, as objects turned white may point to
+** still-black objects. The invariant is restored when sweep ends and
+** all objects are white again.
+*/
+
+#define keepinvariant(g)	((g)->gcstate <= GCSatomic)
+
+
+/*
+** some useful bit tricks
+*/
+#define resetbits(x,m)		((x) &= cast(lu_byte, ~(m)))
+#define setbits(x,m)		((x) |= (m))
+#define testbits(x,m)		((x) & (m))
+#define bitmask(b)		(1<<(b))
+#define bit2mask(b1,b2)		(bitmask(b1) | bitmask(b2))
+#define l_setbit(x,b)		setbits(x, bitmask(b))
+#define resetbit(x,b)		resetbits(x, bitmask(b))
+#define testbit(x,b)		testbits(x, bitmask(b))
+
+
+/* Layout for bit use in 'marked' field: */
+#define WHITE0BIT	0  /* object is white (type 0) */
+#define WHITE1BIT	1  /* object is white (type 1) */
+#define BLACKBIT	2  /* object is black */
+#define FINALIZEDBIT	3  /* object has been marked for finalization */
+/* bit 7 is currently used by tests (luaL_checkmemory) */
+
+#define WHITEBITS	bit2mask(WHITE0BIT, WHITE1BIT)
+
+
+#define iswhite(x)      testbits((x)->marked, WHITEBITS)
+#define isblack(x)      testbit((x)->marked, BLACKBIT)
+#define isgray(x)  /* neither white nor black */  \
+	(!testbits((x)->marked, WHITEBITS | bitmask(BLACKBIT)))
+
+#define tofinalize(x)	testbit((x)->marked, FINALIZEDBIT)
+
+#define otherwhite(g)	((g)->currentwhite ^ WHITEBITS)
+#define isdeadm(ow,m)	(!(((m) ^ WHITEBITS) & (ow)))
+#define isdead(g,v)	isdeadm(otherwhite(g), (v)->marked)
+
+#define changewhite(x)	((x)->marked ^= WHITEBITS)
+#define gray2black(x)	l_setbit((x)->marked, BLACKBIT)
+
+#define luaC_white(g)	cast(lu_byte, (g)->currentwhite & WHITEBITS)
+
+
+/*
+** Does one step of collection when debt becomes positive. 'pre'/'pos'
+** allows some adjustments to be done only when needed. macro
+** 'condchangemem' is used only for heavy tests (forcing a full
+** GC cycle on every opportunity)
+*/
+#define luaC_condGC(L,pre,pos) \
+	{ if (G(L)->GCdebt > 0) { pre; luaC_step(L); pos;}; \
+	  condchangemem(L,pre,pos); }
+
+/* more often than not, 'pre'/'pos' are empty */
+#define luaC_checkGC(L)		luaC_condGC(L,(void)0,(void)0)
+
+
+#define luaC_barrier(L,p,v) (  \
+	(iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ?  \
+	luaC_barrier_(L,obj2gco(p),gcvalue(v)) : cast_void(0))
+
+#define luaC_barrierback(L,p,v) (  \
+	(iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ? \
+	luaC_barrierback_(L,p) : cast_void(0))
+
+#define luaC_objbarrier(L,p,o) (  \
+	(isblack(p) && iswhite(o)) ? \
+	luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))
+
+#define luaC_upvalbarrier(L,uv) ( \
+	(iscollectable((uv)->v) && !upisopen(uv)) ? \
+         luaC_upvalbarrier_(L,uv) : cast_void(0))
+
+LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o);
+LUAI_FUNC void luaC_freeallobjects (lua_State *L);
+LUAI_FUNC void luaC_step (lua_State *L);
+LUAI_FUNC void luaC_runtilstate (lua_State *L, int statesmask);
+LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency);
+LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz);
+LUAI_FUNC void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v);
+LUAI_FUNC void luaC_barrierback_ (lua_State *L, Table *o);
+LUAI_FUNC void luaC_upvalbarrier_ (lua_State *L, UpVal *uv);
+LUAI_FUNC void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt);
+LUAI_FUNC void luaC_upvdeccount (lua_State *L, UpVal *uv);
+
+
+#endif
diff --git a/src/linit.c b/src/linit.c
new file mode 100644
index 0000000..8ce94cc
--- /dev/null
+++ b/src/linit.c
@@ -0,0 +1,68 @@
+/*
+** $Id: linit.c,v 1.38 2015/01/05 13:48:33 roberto Exp $
+** Initialization of libraries for lua.c and other clients
+** See Copyright Notice in lua.h
+*/
+
+
+#define linit_c
+#define LUA_LIB
+
+/*
+** If you embed Lua in your program and need to open the standard
+** libraries, call luaL_openlibs in your program. If you need a
+** different set of libraries, copy this file to your project and edit
+** it to suit your needs.
+**
+** You can also *preload* libraries, so that a later 'require' can
+** open the library, which is already linked to the application.
+** For that, do the following code:
+**
+**  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
+**  lua_pushcfunction(L, luaopen_modname);
+**  lua_setfield(L, -2, modname);
+**  lua_pop(L, 1);  // remove _PRELOAD table
+*/
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+
+#include "lua.h"
+
+#include "lualib.h"
+#include "lauxlib.h"
+
+
+/*
+** these libs are loaded by lua.c and are readily available to any Lua
+** program
+*/
+static const luaL_Reg loadedlibs[] = {
+  {"_G", luaopen_base},
+  {LUA_LOADLIBNAME, luaopen_package},
+  {LUA_COLIBNAME, luaopen_coroutine},
+  {LUA_TABLIBNAME, luaopen_table},
+  {LUA_IOLIBNAME, luaopen_io},
+  {LUA_OSLIBNAME, luaopen_os},
+  {LUA_STRLIBNAME, luaopen_string},
+  {LUA_MATHLIBNAME, luaopen_math},
+  {LUA_UTF8LIBNAME, luaopen_utf8},
+  {LUA_DBLIBNAME, luaopen_debug},
+#if defined(LUA_COMPAT_BITLIB)
+  {LUA_BITLIBNAME, luaopen_bit32},
+#endif
+  {NULL, NULL}
+};
+
+
+LUALIB_API void luaL_openlibs (lua_State *L) {
+  const luaL_Reg *lib;
+  /* "require" functions from 'loadedlibs' and set results to global table */
+  for (lib = loadedlibs; lib->func; lib++) {
+    luaL_requiref(L, lib->name, lib->func, 1);
+    lua_pop(L, 1);  /* remove lib */
+  }
+}
+
diff --git a/src/liolib.c b/src/liolib.c
new file mode 100644
index 0000000..aa78e59
--- /dev/null
+++ b/src/liolib.c
@@ -0,0 +1,768 @@
+/*
+** $Id: liolib.c,v 2.149 2016/05/02 14:03:19 roberto Exp $
+** Standard I/O (and system) library
+** See Copyright Notice in lua.h
+*/
+
+#define liolib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <ctype.h>
+#include <errno.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+
+
+/*
+** Change this macro to accept other modes for 'fopen' besides
+** the standard ones.
+*/
+#if !defined(l_checkmode)
+
+/* accepted extensions to 'mode' in 'fopen' */
+#if !defined(L_MODEEXT)
+#define L_MODEEXT	"b"
+#endif
+
+/* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */
+#define l_checkmode(mode) \
+	(*mode != '\0' && strchr("rwa", *(mode++)) != NULL &&	\
+	(*mode != '+' || (++mode, 1)) &&  /* skip if char is '+' */	\
+	(strspn(mode, L_MODEEXT) == strlen(mode)))
+
+#endif
+
+/*
+** {======================================================
+** l_popen spawns a new process connected to the current
+** one through the file streams.
+** =======================================================
+*/
+
+#if !defined(l_popen)		/* { */
+
+#if defined(LUA_USE_POSIX)	/* { */
+
+#define l_popen(L,c,m)		(fflush(NULL), popen(c,m))
+#define l_pclose(L,file)	(pclose(file))
+
+#elif defined(LUA_USE_WINDOWS)	/* }{ */
+
+#define l_popen(L,c,m)		(_popen(c,m))
+#define l_pclose(L,file)	(_pclose(file))
+
+#else				/* }{ */
+
+/* ISO C definitions */
+#define l_popen(L,c,m)  \
+	  ((void)((void)c, m), \
+	  luaL_error(L, "'popen' not supported"), \
+	  (FILE*)0)
+#define l_pclose(L,file)		((void)L, (void)file, -1)
+
+#endif				/* } */
+
+#endif				/* } */
+
+/* }====================================================== */
+
+
+#if !defined(l_getc)		/* { */
+
+#if defined(LUA_USE_POSIX)
+#define l_getc(f)		getc_unlocked(f)
+#define l_lockfile(f)		flockfile(f)
+#define l_unlockfile(f)		funlockfile(f)
+#else
+#define l_getc(f)		getc(f)
+#define l_lockfile(f)		((void)0)
+#define l_unlockfile(f)		((void)0)
+#endif
+
+#endif				/* } */
+
+
+/*
+** {======================================================
+** l_fseek: configuration for longer offsets
+** =======================================================
+*/
+
+#if !defined(l_fseek)		/* { */
+
+#if defined(LUA_USE_POSIX)	/* { */
+
+#include <sys/types.h>
+
+#define l_fseek(f,o,w)		fseeko(f,o,w)
+#define l_ftell(f)		ftello(f)
+#define l_seeknum		off_t
+
+#elif defined(LUA_USE_WINDOWS) && !defined(_CRTIMP_TYPEINFO) \
+   && defined(_MSC_VER) && (_MSC_VER >= 1400)	/* }{ */
+
+/* Windows (but not DDK) and Visual C++ 2005 or higher */
+#define l_fseek(f,o,w)		_fseeki64(f,o,w)
+#define l_ftell(f)		_ftelli64(f)
+#define l_seeknum		__int64
+
+#else				/* }{ */
+
+/* ISO C definitions */
+#define l_fseek(f,o,w)		fseek(f,o,w)
+#define l_ftell(f)		ftell(f)
+#define l_seeknum		long
+
+#endif				/* } */
+
+#endif				/* } */
+
+/* }====================================================== */
+
+
+#define IO_PREFIX	"_IO_"
+#define IOPREF_LEN	(sizeof(IO_PREFIX)/sizeof(char) - 1)
+#define IO_INPUT	(IO_PREFIX "input")
+#define IO_OUTPUT	(IO_PREFIX "output")
+
+
+typedef luaL_Stream LStream;
+
+
+#define tolstream(L)	((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE))
+
+#define isclosed(p)	((p)->closef == NULL)
+
+
+static int io_type (lua_State *L) {
+  LStream *p;
+  luaL_checkany(L, 1);
+  p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);
+  if (p == NULL)
+    lua_pushnil(L);  /* not a file */
+  else if (isclosed(p))
+    lua_pushliteral(L, "closed file");
+  else
+    lua_pushliteral(L, "file");
+  return 1;
+}
+
+
+static int f_tostring (lua_State *L) {
+  LStream *p = tolstream(L);
+  if (isclosed(p))
+    lua_pushliteral(L, "file (closed)");
+  else
+    lua_pushfstring(L, "file (%p)", p->f);
+  return 1;
+}
+
+
+static FILE *tofile (lua_State *L) {
+  LStream *p = tolstream(L);
+  if (isclosed(p))
+    luaL_error(L, "attempt to use a closed file");
+  lua_assert(p->f);
+  return p->f;
+}
+
+
+/*
+** When creating file handles, always creates a 'closed' file handle
+** before opening the actual file; so, if there is a memory error, the
+** handle is in a consistent state.
+*/
+static LStream *newprefile (lua_State *L) {
+  LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));
+  p->closef = NULL;  /* mark file handle as 'closed' */
+  luaL_setmetatable(L, LUA_FILEHANDLE);
+  return p;
+}
+
+
+/*
+** Calls the 'close' function from a file handle. The 'volatile' avoids
+** a bug in some versions of the Clang compiler (e.g., clang 3.0 for
+** 32 bits).
+*/
+static int aux_close (lua_State *L) {
+  LStream *p = tolstream(L);
+  volatile lua_CFunction cf = p->closef;
+  p->closef = NULL;  /* mark stream as closed */
+  return (*cf)(L);  /* close it */
+}
+
+
+static int io_close (lua_State *L) {
+  if (lua_isnone(L, 1))  /* no argument? */
+    lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT);  /* use standard output */
+  tofile(L);  /* make sure argument is an open stream */
+  return aux_close(L);
+}
+
+
+static int f_gc (lua_State *L) {
+  LStream *p = tolstream(L);
+  if (!isclosed(p) && p->f != NULL)
+    aux_close(L);  /* ignore closed and incompletely open files */
+  return 0;
+}
+
+
+/*
+** function to close regular files
+*/
+static int io_fclose (lua_State *L) {
+  LStream *p = tolstream(L);
+  int res = fclose(p->f);
+  return luaL_fileresult(L, (res == 0), NULL);
+}
+
+
+static LStream *newfile (lua_State *L) {
+  LStream *p = newprefile(L);
+  p->f = NULL;
+  p->closef = &io_fclose;
+  return p;
+}
+
+
+static void opencheck (lua_State *L, const char *fname, const char *mode) {
+  LStream *p = newfile(L);
+  p->f = fopen(fname, mode);
+  if (p->f == NULL)
+    luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno));
+}
+
+
+static int io_open (lua_State *L) {
+  const char *filename = luaL_checkstring(L, 1);
+  const char *mode = luaL_optstring(L, 2, "r");
+  LStream *p = newfile(L);
+  const char *md = mode;  /* to traverse/check mode */
+  luaL_argcheck(L, l_checkmode(md), 2, "invalid mode");
+  p->f = fopen(filename, mode);
+  return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
+}
+
+
+/*
+** function to close 'popen' files
+*/
+static int io_pclose (lua_State *L) {
+  LStream *p = tolstream(L);
+  return luaL_execresult(L, l_pclose(L, p->f));
+}
+
+
+static int io_popen (lua_State *L) {
+  const char *filename = luaL_checkstring(L, 1);
+  const char *mode = luaL_optstring(L, 2, "r");
+  LStream *p = newprefile(L);
+  p->f = l_popen(L, filename, mode);
+  p->closef = &io_pclose;
+  return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
+}
+
+
+static int io_tmpfile (lua_State *L) {
+  LStream *p = newfile(L);
+  p->f = tmpfile();
+  return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
+}
+
+
+static FILE *getiofile (lua_State *L, const char *findex) {
+  LStream *p;
+  lua_getfield(L, LUA_REGISTRYINDEX, findex);
+  p = (LStream *)lua_touserdata(L, -1);
+  if (isclosed(p))
+    luaL_error(L, "standard %s file is closed", findex + IOPREF_LEN);
+  return p->f;
+}
+
+
+static int g_iofile (lua_State *L, const char *f, const char *mode) {
+  if (!lua_isnoneornil(L, 1)) {
+    const char *filename = lua_tostring(L, 1);
+    if (filename)
+      opencheck(L, filename, mode);
+    else {
+      tofile(L);  /* check that it's a valid file handle */
+      lua_pushvalue(L, 1);
+    }
+    lua_setfield(L, LUA_REGISTRYINDEX, f);
+  }
+  /* return current value */
+  lua_getfield(L, LUA_REGISTRYINDEX, f);
+  return 1;
+}
+
+
+static int io_input (lua_State *L) {
+  return g_iofile(L, IO_INPUT, "r");
+}
+
+
+static int io_output (lua_State *L) {
+  return g_iofile(L, IO_OUTPUT, "w");
+}
+
+
+static int io_readline (lua_State *L);
+
+
+/*
+** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit
+** in the limit for upvalues of a closure)
+*/
+#define MAXARGLINE	250
+
+static void aux_lines (lua_State *L, int toclose) {
+  int n = lua_gettop(L) - 1;  /* number of arguments to read */
+  luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments");
+  lua_pushinteger(L, n);  /* number of arguments to read */
+  lua_pushboolean(L, toclose);  /* close/not close file when finished */
+  lua_rotate(L, 2, 2);  /* move 'n' and 'toclose' to their positions */
+  lua_pushcclosure(L, io_readline, 3 + n);
+}
+
+
+static int f_lines (lua_State *L) {
+  tofile(L);  /* check that it's a valid file handle */
+  aux_lines(L, 0);
+  return 1;
+}
+
+
+static int io_lines (lua_State *L) {
+  int toclose;
+  if (lua_isnone(L, 1)) lua_pushnil(L);  /* at least one argument */
+  if (lua_isnil(L, 1)) {  /* no file name? */
+    lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT);  /* get default input */
+    lua_replace(L, 1);  /* put it at index 1 */
+    tofile(L);  /* check that it's a valid file handle */
+    toclose = 0;  /* do not close it after iteration */
+  }
+  else {  /* open a new file */
+    const char *filename = luaL_checkstring(L, 1);
+    opencheck(L, filename, "r");
+    lua_replace(L, 1);  /* put file at index 1 */
+    toclose = 1;  /* close it after iteration */
+  }
+  aux_lines(L, toclose);
+  return 1;
+}
+
+
+/*
+** {======================================================
+** READ
+** =======================================================
+*/
+
+
+/* maximum length of a numeral */
+#if !defined (L_MAXLENNUM)
+#define L_MAXLENNUM     200
+#endif
+
+
+/* auxiliary structure used by 'read_number' */
+typedef struct {
+  FILE *f;  /* file being read */
+  int c;  /* current character (look ahead) */
+  int n;  /* number of elements in buffer 'buff' */
+  char buff[L_MAXLENNUM + 1];  /* +1 for ending '\0' */
+} RN;
+
+
+/*
+** Add current char to buffer (if not out of space) and read next one
+*/
+static int nextc (RN *rn) {
+  if (rn->n >= L_MAXLENNUM) {  /* buffer overflow? */
+    rn->buff[0] = '\0';  /* invalidate result */
+    return 0;  /* fail */
+  }
+  else {
+    rn->buff[rn->n++] = rn->c;  /* save current char */
+    rn->c = l_getc(rn->f);  /* read next one */
+    return 1;
+  }
+}
+
+
+/*
+** Accept current char if it is in 'set' (of size 2)
+*/
+static int test2 (RN *rn, const char *set) {
+  if (rn->c == set[0] || rn->c == set[1])
+    return nextc(rn);
+  else return 0;
+}
+
+
+/*
+** Read a sequence of (hex)digits
+*/
+static int readdigits (RN *rn, int hex) {
+  int count = 0;
+  while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn))
+    count++;
+  return count;
+}
+
+
+/*
+** Read a number: first reads a valid prefix of a numeral into a buffer.
+** Then it calls 'lua_stringtonumber' to check whether the format is
+** correct and to convert it to a Lua number
+*/
+static int read_number (lua_State *L, FILE *f) {
+  RN rn;
+  int count = 0;
+  int hex = 0;
+  char decp[2];
+  rn.f = f; rn.n = 0;
+  decp[0] = lua_getlocaledecpoint();  /* get decimal point from locale */
+  decp[1] = '.';  /* always accept a dot */
+  l_lockfile(rn.f);
+  do { rn.c = l_getc(rn.f); } while (isspace(rn.c));  /* skip spaces */
+  test2(&rn, "-+");  /* optional signal */
+  if (test2(&rn, "00")) {
+    if (test2(&rn, "xX")) hex = 1;  /* numeral is hexadecimal */
+    else count = 1;  /* count initial '0' as a valid digit */
+  }
+  count += readdigits(&rn, hex);  /* integral part */
+  if (test2(&rn, decp))  /* decimal point? */
+    count += readdigits(&rn, hex);  /* fractional part */
+  if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) {  /* exponent mark? */
+    test2(&rn, "-+");  /* exponent signal */
+    readdigits(&rn, 0);  /* exponent digits */
+  }
+  ungetc(rn.c, rn.f);  /* unread look-ahead char */
+  l_unlockfile(rn.f);
+  rn.buff[rn.n] = '\0';  /* finish string */
+  if (lua_stringtonumber(L, rn.buff))  /* is this a valid number? */
+    return 1;  /* ok */
+  else {  /* invalid format */
+   lua_pushnil(L);  /* "result" to be removed */
+   return 0;  /* read fails */
+  }
+}
+
+
+static int test_eof (lua_State *L, FILE *f) {
+  int c = getc(f);
+  ungetc(c, f);  /* no-op when c == EOF */
+  lua_pushliteral(L, "");
+  return (c != EOF);
+}
+
+
+static int read_line (lua_State *L, FILE *f, int chop) {
+  luaL_Buffer b;
+  int c = '\0';
+  luaL_buffinit(L, &b);
+  while (c != EOF && c != '\n') {  /* repeat until end of line */
+    char *buff = luaL_prepbuffer(&b);  /* preallocate buffer */
+    int i = 0;
+    l_lockfile(f);  /* no memory errors can happen inside the lock */
+    while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
+      buff[i++] = c;
+    l_unlockfile(f);
+    luaL_addsize(&b, i);
+  }
+  if (!chop && c == '\n')  /* want a newline and have one? */
+    luaL_addchar(&b, c);  /* add ending newline to result */
+  luaL_pushresult(&b);  /* close buffer */
+  /* return ok if read something (either a newline or something else) */
+  return (c == '\n' || lua_rawlen(L, -1) > 0);
+}
+
+
+static void read_all (lua_State *L, FILE *f) {
+  size_t nr;
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  do {  /* read file in chunks of LUAL_BUFFERSIZE bytes */
+    char *p = luaL_prepbuffer(&b);
+    nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f);
+    luaL_addsize(&b, nr);
+  } while (nr == LUAL_BUFFERSIZE);
+  luaL_pushresult(&b);  /* close buffer */
+}
+
+
+static int read_chars (lua_State *L, FILE *f, size_t n) {
+  size_t nr;  /* number of chars actually read */
+  char *p;
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  p = luaL_prepbuffsize(&b, n);  /* prepare buffer to read whole block */
+  nr = fread(p, sizeof(char), n, f);  /* try to read 'n' chars */
+  luaL_addsize(&b, nr);
+  luaL_pushresult(&b);  /* close buffer */
+  return (nr > 0);  /* true iff read something */
+}
+
+
+static int g_read (lua_State *L, FILE *f, int first) {
+  int nargs = lua_gettop(L) - 1;
+  int success;
+  int n;
+  clearerr(f);
+  if (nargs == 0) {  /* no arguments? */
+    success = read_line(L, f, 1);
+    n = first+1;  /* to return 1 result */
+  }
+  else {  /* ensure stack space for all results and for auxlib's buffer */
+    luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
+    success = 1;
+    for (n = first; nargs-- && success; n++) {
+      if (lua_type(L, n) == LUA_TNUMBER) {
+        size_t l = (size_t)luaL_checkinteger(L, n);
+        success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
+      }
+      else {
+        const char *p = luaL_checkstring(L, n);
+        if (*p == '*') p++;  /* skip optional '*' (for compatibility) */
+        switch (*p) {
+          case 'n':  /* number */
+            success = read_number(L, f);
+            break;
+          case 'l':  /* line */
+            success = read_line(L, f, 1);
+            break;
+          case 'L':  /* line with end-of-line */
+            success = read_line(L, f, 0);
+            break;
+          case 'a':  /* file */
+            read_all(L, f);  /* read entire file */
+            success = 1; /* always success */
+            break;
+          default:
+            return luaL_argerror(L, n, "invalid format");
+        }
+      }
+    }
+  }
+  if (ferror(f))
+    return luaL_fileresult(L, 0, NULL);
+  if (!success) {
+    lua_pop(L, 1);  /* remove last result */
+    lua_pushnil(L);  /* push nil instead */
+  }
+  return n - first;
+}
+
+
+static int io_read (lua_State *L) {
+  return g_read(L, getiofile(L, IO_INPUT), 1);
+}
+
+
+static int f_read (lua_State *L) {
+  return g_read(L, tofile(L), 2);
+}
+
+
+static int io_readline (lua_State *L) {
+  LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
+  int i;
+  int n = (int)lua_tointeger(L, lua_upvalueindex(2));
+  if (isclosed(p))  /* file is already closed? */
+    return luaL_error(L, "file is already closed");
+  lua_settop(L , 1);
+  luaL_checkstack(L, n, "too many arguments");
+  for (i = 1; i <= n; i++)  /* push arguments to 'g_read' */
+    lua_pushvalue(L, lua_upvalueindex(3 + i));
+  n = g_read(L, p->f, 2);  /* 'n' is number of results */
+  lua_assert(n > 0);  /* should return at least a nil */
+  if (lua_toboolean(L, -n))  /* read at least one value? */
+    return n;  /* return them */
+  else {  /* first result is nil: EOF or error */
+    if (n > 1) {  /* is there error information? */
+      /* 2nd result is error message */
+      return luaL_error(L, "%s", lua_tostring(L, -n + 1));
+    }
+    if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */
+      lua_settop(L, 0);
+      lua_pushvalue(L, lua_upvalueindex(1));
+      aux_close(L);  /* close it */
+    }
+    return 0;
+  }
+}
+
+/* }====================================================== */
+
+
+static int g_write (lua_State *L, FILE *f, int arg) {
+  int nargs = lua_gettop(L) - arg;
+  int status = 1;
+  for (; nargs--; arg++) {
+    if (lua_type(L, arg) == LUA_TNUMBER) {
+      /* optimization: could be done exactly as for strings */
+      int len = lua_isinteger(L, arg)
+                ? fprintf(f, LUA_INTEGER_FMT, lua_tointeger(L, arg))
+                : fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg));
+      status = status && (len > 0);
+    }
+    else {
+      size_t l;
+      const char *s = luaL_checklstring(L, arg, &l);
+      status = status && (fwrite(s, sizeof(char), l, f) == l);
+    }
+  }
+  if (status) return 1;  /* file handle already on stack top */
+  else return luaL_fileresult(L, status, NULL);
+}
+
+
+static int io_write (lua_State *L) {
+  return g_write(L, getiofile(L, IO_OUTPUT), 1);
+}
+
+
+static int f_write (lua_State *L) {
+  FILE *f = tofile(L);
+  lua_pushvalue(L, 1);  /* push file at the stack top (to be returned) */
+  return g_write(L, f, 2);
+}
+
+
+static int f_seek (lua_State *L) {
+  static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
+  static const char *const modenames[] = {"set", "cur", "end", NULL};
+  FILE *f = tofile(L);
+  int op = luaL_checkoption(L, 2, "cur", modenames);
+  lua_Integer p3 = luaL_optinteger(L, 3, 0);
+  l_seeknum offset = (l_seeknum)p3;
+  luaL_argcheck(L, (lua_Integer)offset == p3, 3,
+                  "not an integer in proper range");
+  op = l_fseek(f, offset, mode[op]);
+  if (op)
+    return luaL_fileresult(L, 0, NULL);  /* error */
+  else {
+    lua_pushinteger(L, (lua_Integer)l_ftell(f));
+    return 1;
+  }
+}
+
+
+static int f_setvbuf (lua_State *L) {
+  static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
+  static const char *const modenames[] = {"no", "full", "line", NULL};
+  FILE *f = tofile(L);
+  int op = luaL_checkoption(L, 2, NULL, modenames);
+  lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
+  int res = setvbuf(f, NULL, mode[op], (size_t)sz);
+  return luaL_fileresult(L, res == 0, NULL);
+}
+
+
+
+static int io_flush (lua_State *L) {
+  return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
+}
+
+
+static int f_flush (lua_State *L) {
+  return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);
+}
+
+
+/*
+** functions for 'io' library
+*/
+static const luaL_Reg iolib[] = {
+  {"close", io_close},
+  {"flush", io_flush},
+  {"input", io_input},
+  {"lines", io_lines},
+  {"open", io_open},
+  {"output", io_output},
+  {"popen", io_popen},
+  {"read", io_read},
+  {"tmpfile", io_tmpfile},
+  {"type", io_type},
+  {"write", io_write},
+  {NULL, NULL}
+};
+
+
+/*
+** methods for file handles
+*/
+static const luaL_Reg flib[] = {
+  {"close", io_close},
+  {"flush", f_flush},
+  {"lines", f_lines},
+  {"read", f_read},
+  {"seek", f_seek},
+  {"setvbuf", f_setvbuf},
+  {"write", f_write},
+  {"__gc", f_gc},
+  {"__tostring", f_tostring},
+  {NULL, NULL}
+};
+
+
+static void createmeta (lua_State *L) {
+  luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
+  lua_pushvalue(L, -1);  /* push metatable */
+  lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
+  luaL_setfuncs(L, flib, 0);  /* add file methods to new metatable */
+  lua_pop(L, 1);  /* pop new metatable */
+}
+
+
+/*
+** function to (not) close the standard files stdin, stdout, and stderr
+*/
+static int io_noclose (lua_State *L) {
+  LStream *p = tolstream(L);
+  p->closef = &io_noclose;  /* keep file opened */
+  lua_pushnil(L);
+  lua_pushliteral(L, "cannot close standard file");
+  return 2;
+}
+
+
+static void createstdfile (lua_State *L, FILE *f, const char *k,
+                           const char *fname) {
+  LStream *p = newprefile(L);
+  p->f = f;
+  p->closef = &io_noclose;
+  if (k != NULL) {
+    lua_pushvalue(L, -1);
+    lua_setfield(L, LUA_REGISTRYINDEX, k);  /* add file to registry */
+  }
+  lua_setfield(L, -2, fname);  /* add file to module */
+}
+
+
+LUAMOD_API int luaopen_io (lua_State *L) {
+  luaL_newlib(L, iolib);  /* new module */
+  createmeta(L);
+  /* create (and set) default files */
+  createstdfile(L, stdin, IO_INPUT, "stdin");
+  createstdfile(L, stdout, IO_OUTPUT, "stdout");
+  createstdfile(L, stderr, NULL, "stderr");
+  return 1;
+}
+
diff --git a/src/llex.c b/src/llex.c
new file mode 100644
index 0000000..7032827
--- /dev/null
+++ b/src/llex.c
@@ -0,0 +1,565 @@
+/*
+** $Id: llex.c,v 2.96 2016/05/02 14:02:12 roberto Exp $
+** Lexical Analyzer
+** See Copyright Notice in lua.h
+*/
+
+#define llex_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <locale.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lctype.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
+#include "llex.h"
+#include "lobject.h"
+#include "lparser.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "lzio.h"
+
+
+
+#define next(ls) (ls->current = zgetc(ls->z))
+
+
+
+#define currIsNewline(ls)	(ls->current == '\n' || ls->current == '\r')
+
+
+/* ORDER RESERVED */
+static const char *const luaX_tokens [] = {
+    "and", "break", "do", "else", "elseif",
+    "end", "false", "for", "function", "goto", "if",
+    "in", "local", "nil", "not", "or", "repeat",
+    "return", "then", "true", "until", "while",
+    "//", "..", "...", "==", ">=", "<=", "~=",
+    "<<", ">>", "::", "<eof>",
+    "<number>", "<integer>", "<name>", "<string>"
+};
+
+
+#define save_and_next(ls) (save(ls, ls->current), next(ls))
+
+
+static l_noret lexerror (LexState *ls, const char *msg, int token);
+
+
+static void save (LexState *ls, int c) {
+  Mbuffer *b = ls->buff;
+  if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) {
+    size_t newsize;
+    if (luaZ_sizebuffer(b) >= MAX_SIZE/2)
+      lexerror(ls, "lexical element too long", 0);
+    newsize = luaZ_sizebuffer(b) * 2;
+    luaZ_resizebuffer(ls->L, b, newsize);
+  }
+  b->buffer[luaZ_bufflen(b)++] = cast(char, c);
+}
+
+
+void luaX_init (lua_State *L) {
+  int i;
+  TString *e = luaS_newliteral(L, LUA_ENV);  /* create env name */
+  luaC_fix(L, obj2gco(e));  /* never collect this name */
+  for (i=0; i<NUM_RESERVED; i++) {
+    TString *ts = luaS_new(L, luaX_tokens[i]);
+    luaC_fix(L, obj2gco(ts));  /* reserved words are never collected */
+    ts->extra = cast_byte(i+1);  /* reserved word */
+  }
+}
+
+
+const char *luaX_token2str (LexState *ls, int token) {
+  if (token < FIRST_RESERVED) {  /* single-byte symbols? */
+    lua_assert(token == cast_uchar(token));
+    return luaO_pushfstring(ls->L, "'%c'", token);
+  }
+  else {
+    const char *s = luaX_tokens[token - FIRST_RESERVED];
+    if (token < TK_EOS)  /* fixed format (symbols and reserved words)? */
+      return luaO_pushfstring(ls->L, "'%s'", s);
+    else  /* names, strings, and numerals */
+      return s;
+  }
+}
+
+
+static const char *txtToken (LexState *ls, int token) {
+  switch (token) {
+    case TK_NAME: case TK_STRING:
+    case TK_FLT: case TK_INT:
+      save(ls, '\0');
+      return luaO_pushfstring(ls->L, "'%s'", luaZ_buffer(ls->buff));
+    default:
+      return luaX_token2str(ls, token);
+  }
+}
+
+
+static l_noret lexerror (LexState *ls, const char *msg, int token) {
+  msg = luaG_addinfo(ls->L, msg, ls->source, ls->linenumber);
+  if (token)
+    luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token));
+  luaD_throw(ls->L, LUA_ERRSYNTAX);
+}
+
+
+l_noret luaX_syntaxerror (LexState *ls, const char *msg) {
+  lexerror(ls, msg, ls->t.token);
+}
+
+
+/*
+** creates a new string and anchors it in scanner's table so that
+** it will not be collected until the end of the compilation
+** (by that time it should be anchored somewhere)
+*/
+TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
+  lua_State *L = ls->L;
+  TValue *o;  /* entry for 'str' */
+  TString *ts = luaS_newlstr(L, str, l);  /* create new string */
+  setsvalue2s(L, L->top++, ts);  /* temporarily anchor it in stack */
+  o = luaH_set(L, ls->h, L->top - 1);
+  if (ttisnil(o)) {  /* not in use yet? */
+    /* boolean value does not need GC barrier;
+       table has no metatable, so it does not need to invalidate cache */
+    setbvalue(o, 1);  /* t[string] = true */
+    luaC_checkGC(L);
+  }
+  else {  /* string already present */
+    ts = tsvalue(keyfromval(o));  /* re-use value previously stored */
+  }
+  L->top--;  /* remove string from stack */
+  return ts;
+}
+
+
+/*
+** increment line number and skips newline sequence (any of
+** \n, \r, \n\r, or \r\n)
+*/
+static void inclinenumber (LexState *ls) {
+  int old = ls->current;
+  lua_assert(currIsNewline(ls));
+  next(ls);  /* skip '\n' or '\r' */
+  if (currIsNewline(ls) && ls->current != old)
+    next(ls);  /* skip '\n\r' or '\r\n' */
+  if (++ls->linenumber >= MAX_INT)
+    lexerror(ls, "chunk has too many lines", 0);
+}
+
+
+void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source,
+                    int firstchar) {
+  ls->t.token = 0;
+  ls->L = L;
+  ls->current = firstchar;
+  ls->lookahead.token = TK_EOS;  /* no look-ahead token */
+  ls->z = z;
+  ls->fs = NULL;
+  ls->linenumber = 1;
+  ls->lastline = 1;
+  ls->source = source;
+  ls->envn = luaS_newliteral(L, LUA_ENV);  /* get env name */
+  luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER);  /* initialize buffer */
+}
+
+
+
+/*
+** =======================================================
+** LEXICAL ANALYZER
+** =======================================================
+*/
+
+
+static int check_next1 (LexState *ls, int c) {
+  if (ls->current == c) {
+    next(ls);
+    return 1;
+  }
+  else return 0;
+}
+
+
+/*
+** Check whether current char is in set 'set' (with two chars) and
+** saves it
+*/
+static int check_next2 (LexState *ls, const char *set) {
+  lua_assert(set[2] == '\0');
+  if (ls->current == set[0] || ls->current == set[1]) {
+    save_and_next(ls);
+    return 1;
+  }
+  else return 0;
+}
+
+
+/* LUA_NUMBER */
+/*
+** this function is quite liberal in what it accepts, as 'luaO_str2num'
+** will reject ill-formed numerals.
+*/
+static int read_numeral (LexState *ls, SemInfo *seminfo) {
+  TValue obj;
+  const char *expo = "Ee";
+  int first = ls->current;
+  lua_assert(lisdigit(ls->current));
+  save_and_next(ls);
+  if (first == '0' && check_next2(ls, "xX"))  /* hexadecimal? */
+    expo = "Pp";
+  for (;;) {
+    if (check_next2(ls, expo))  /* exponent part? */
+      check_next2(ls, "-+");  /* optional exponent sign */
+    if (lisxdigit(ls->current))
+      save_and_next(ls);
+    else if (ls->current == '.')
+      save_and_next(ls);
+    else break;
+  }
+  save(ls, '\0');
+  if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0)  /* format error? */
+    lexerror(ls, "malformed number", TK_FLT);
+  if (ttisinteger(&obj)) {
+    seminfo->i = ivalue(&obj);
+    return TK_INT;
+  }
+  else {
+    lua_assert(ttisfloat(&obj));
+    seminfo->r = fltvalue(&obj);
+    return TK_FLT;
+  }
+}
+
+
+/*
+** skip a sequence '[=*[' or ']=*]'; if sequence is well formed, return
+** its number of '='s; otherwise, return a negative number (-1 iff there
+** are no '='s after initial bracket)
+*/
+static int skip_sep (LexState *ls) {
+  int count = 0;
+  int s = ls->current;
+  lua_assert(s == '[' || s == ']');
+  save_and_next(ls);
+  while (ls->current == '=') {
+    save_and_next(ls);
+    count++;
+  }
+  return (ls->current == s) ? count : (-count) - 1;
+}
+
+
+static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
+  int line = ls->linenumber;  /* initial line (for error message) */
+  save_and_next(ls);  /* skip 2nd '[' */
+  if (currIsNewline(ls))  /* string starts with a newline? */
+    inclinenumber(ls);  /* skip it */
+  for (;;) {
+    switch (ls->current) {
+      case EOZ: {  /* error */
+        const char *what = (seminfo ? "string" : "comment");
+        const char *msg = luaO_pushfstring(ls->L,
+                     "unfinished long %s (starting at line %d)", what, line);
+        lexerror(ls, msg, TK_EOS);
+        break;  /* to avoid warnings */
+      }
+      case ']': {
+        if (skip_sep(ls) == sep) {
+          save_and_next(ls);  /* skip 2nd ']' */
+          goto endloop;
+        }
+        break;
+      }
+      case '\n': case '\r': {
+        save(ls, '\n');
+        inclinenumber(ls);
+        if (!seminfo) luaZ_resetbuffer(ls->buff);  /* avoid wasting space */
+        break;
+      }
+      default: {
+        if (seminfo) save_and_next(ls);
+        else next(ls);
+      }
+    }
+  } endloop:
+  if (seminfo)
+    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep),
+                                     luaZ_bufflen(ls->buff) - 2*(2 + sep));
+}
+
+
+static void esccheck (LexState *ls, int c, const char *msg) {
+  if (!c) {
+    if (ls->current != EOZ)
+      save_and_next(ls);  /* add current to buffer for error message */
+    lexerror(ls, msg, TK_STRING);
+  }
+}
+
+
+static int gethexa (LexState *ls) {
+  save_and_next(ls);
+  esccheck (ls, lisxdigit(ls->current), "hexadecimal digit expected");
+  return luaO_hexavalue(ls->current);
+}
+
+
+static int readhexaesc (LexState *ls) {
+  int r = gethexa(ls);
+  r = (r << 4) + gethexa(ls);
+  luaZ_buffremove(ls->buff, 2);  /* remove saved chars from buffer */
+  return r;
+}
+
+
+static unsigned long readutf8esc (LexState *ls) {
+  unsigned long r;
+  int i = 4;  /* chars to be removed: '\', 'u', '{', and first digit */
+  save_and_next(ls);  /* skip 'u' */
+  esccheck(ls, ls->current == '{', "missing '{'");
+  r = gethexa(ls);  /* must have at least one digit */
+  while ((save_and_next(ls), lisxdigit(ls->current))) {
+    i++;
+    r = (r << 4) + luaO_hexavalue(ls->current);
+    esccheck(ls, r <= 0x10FFFF, "UTF-8 value too large");
+  }
+  esccheck(ls, ls->current == '}', "missing '}'");
+  next(ls);  /* skip '}' */
+  luaZ_buffremove(ls->buff, i);  /* remove saved chars from buffer */
+  return r;
+}
+
+
+static void utf8esc (LexState *ls) {
+  char buff[UTF8BUFFSZ];
+  int n = luaO_utf8esc(buff, readutf8esc(ls));
+  for (; n > 0; n--)  /* add 'buff' to string */
+    save(ls, buff[UTF8BUFFSZ - n]);
+}
+
+
+static int readdecesc (LexState *ls) {
+  int i;
+  int r = 0;  /* result accumulator */
+  for (i = 0; i < 3 && lisdigit(ls->current); i++) {  /* read up to 3 digits */
+    r = 10*r + ls->current - '0';
+    save_and_next(ls);
+  }
+  esccheck(ls, r <= UCHAR_MAX, "decimal escape too large");
+  luaZ_buffremove(ls->buff, i);  /* remove read digits from buffer */
+  return r;
+}
+
+
+static void read_string (LexState *ls, int del, SemInfo *seminfo) {
+  save_and_next(ls);  /* keep delimiter (for error messages) */
+  while (ls->current != del) {
+    switch (ls->current) {
+      case EOZ:
+        lexerror(ls, "unfinished string", TK_EOS);
+        break;  /* to avoid warnings */
+      case '\n':
+      case '\r':
+        lexerror(ls, "unfinished string", TK_STRING);
+        break;  /* to avoid warnings */
+      case '\\': {  /* escape sequences */
+        int c;  /* final character to be saved */
+        save_and_next(ls);  /* keep '\\' for error messages */
+        switch (ls->current) {
+          case 'a': c = '\a'; goto read_save;
+          case 'b': c = '\b'; goto read_save;
+          case 'f': c = '\f'; goto read_save;
+          case 'n': c = '\n'; goto read_save;
+          case 'r': c = '\r'; goto read_save;
+          case 't': c = '\t'; goto read_save;
+          case 'v': c = '\v'; goto read_save;
+          case 'x': c = readhexaesc(ls); goto read_save;
+          case 'u': utf8esc(ls);  goto no_save;
+          case '\n': case '\r':
+            inclinenumber(ls); c = '\n'; goto only_save;
+          case '\\': case '\"': case '\'':
+            c = ls->current; goto read_save;
+          case EOZ: goto no_save;  /* will raise an error next loop */
+          case 'z': {  /* zap following span of spaces */
+            luaZ_buffremove(ls->buff, 1);  /* remove '\\' */
+            next(ls);  /* skip the 'z' */
+            while (lisspace(ls->current)) {
+              if (currIsNewline(ls)) inclinenumber(ls);
+              else next(ls);
+            }
+            goto no_save;
+          }
+          default: {
+            esccheck(ls, lisdigit(ls->current), "invalid escape sequence");
+            c = readdecesc(ls);  /* digital escape '\ddd' */
+            goto only_save;
+          }
+        }
+       read_save:
+         next(ls);
+         /* go through */
+       only_save:
+         luaZ_buffremove(ls->buff, 1);  /* remove '\\' */
+         save(ls, c);
+         /* go through */
+       no_save: break;
+      }
+      default:
+        save_and_next(ls);
+    }
+  }
+  save_and_next(ls);  /* skip delimiter */
+  seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1,
+                                   luaZ_bufflen(ls->buff) - 2);
+}
+
+
+static int llex (LexState *ls, SemInfo *seminfo) {
+  luaZ_resetbuffer(ls->buff);
+  for (;;) {
+    switch (ls->current) {
+      case '\n': case '\r': {  /* line breaks */
+        inclinenumber(ls);
+        break;
+      }
+      case ' ': case '\f': case '\t': case '\v': {  /* spaces */
+        next(ls);
+        break;
+      }
+      case '-': {  /* '-' or '--' (comment) */
+        next(ls);
+        if (ls->current != '-') return '-';
+        /* else is a comment */
+        next(ls);
+        if (ls->current == '[') {  /* long comment? */
+          int sep = skip_sep(ls);
+          luaZ_resetbuffer(ls->buff);  /* 'skip_sep' may dirty the buffer */
+          if (sep >= 0) {
+            read_long_string(ls, NULL, sep);  /* skip long comment */
+            luaZ_resetbuffer(ls->buff);  /* previous call may dirty the buff. */
+            break;
+          }
+        }
+        /* else short comment */
+        while (!currIsNewline(ls) && ls->current != EOZ)
+          next(ls);  /* skip until end of line (or end of file) */
+        break;
+      }
+      case '[': {  /* long string or simply '[' */
+        int sep = skip_sep(ls);
+        if (sep >= 0) {
+          read_long_string(ls, seminfo, sep);
+          return TK_STRING;
+        }
+        else if (sep != -1)  /* '[=...' missing second bracket */
+          lexerror(ls, "invalid long string delimiter", TK_STRING);
+        return '[';
+      }
+      case '=': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_EQ;
+        else return '=';
+      }
+      case '<': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_LE;
+        else if (check_next1(ls, '<')) return TK_SHL;
+        else return '<';
+      }
+      case '>': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_GE;
+        else if (check_next1(ls, '>')) return TK_SHR;
+        else return '>';
+      }
+      case '/': {
+        next(ls);
+        if (check_next1(ls, '/')) return TK_IDIV;
+        else return '/';
+      }
+      case '~': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_NE;
+        else return '~';
+      }
+      case ':': {
+        next(ls);
+        if (check_next1(ls, ':')) return TK_DBCOLON;
+        else return ':';
+      }
+      case '"': case '\'': {  /* short literal strings */
+        read_string(ls, ls->current, seminfo);
+        return TK_STRING;
+      }
+      case '.': {  /* '.', '..', '...', or number */
+        save_and_next(ls);
+        if (check_next1(ls, '.')) {
+          if (check_next1(ls, '.'))
+            return TK_DOTS;   /* '...' */
+          else return TK_CONCAT;   /* '..' */
+        }
+        else if (!lisdigit(ls->current)) return '.';
+        else return read_numeral(ls, seminfo);
+      }
+      case '0': case '1': case '2': case '3': case '4':
+      case '5': case '6': case '7': case '8': case '9': {
+        return read_numeral(ls, seminfo);
+      }
+      case EOZ: {
+        return TK_EOS;
+      }
+      default: {
+        if (lislalpha(ls->current)) {  /* identifier or reserved word? */
+          TString *ts;
+          do {
+            save_and_next(ls);
+          } while (lislalnum(ls->current));
+          ts = luaX_newstring(ls, luaZ_buffer(ls->buff),
+                                  luaZ_bufflen(ls->buff));
+          seminfo->ts = ts;
+          if (isreserved(ts))  /* reserved word? */
+            return ts->extra - 1 + FIRST_RESERVED;
+          else {
+            return TK_NAME;
+          }
+        }
+        else {  /* single-char tokens (+ - / ...) */
+          int c = ls->current;
+          next(ls);
+          return c;
+        }
+      }
+    }
+  }
+}
+
+
+void luaX_next (LexState *ls) {
+  ls->lastline = ls->linenumber;
+  if (ls->lookahead.token != TK_EOS) {  /* is there a look-ahead token? */
+    ls->t = ls->lookahead;  /* use this one */
+    ls->lookahead.token = TK_EOS;  /* and discharge it */
+  }
+  else
+    ls->t.token = llex(ls, &ls->t.seminfo);  /* read next token */
+}
+
+
+int luaX_lookahead (LexState *ls) {
+  lua_assert(ls->lookahead.token == TK_EOS);
+  ls->lookahead.token = llex(ls, &ls->lookahead.seminfo);
+  return ls->lookahead.token;
+}
+
diff --git a/src/llex.h b/src/llex.h
new file mode 100644
index 0000000..2363d87
--- /dev/null
+++ b/src/llex.h
@@ -0,0 +1,85 @@
+/*
+** $Id: llex.h,v 1.79 2016/05/02 14:02:12 roberto Exp $
+** Lexical Analyzer
+** See Copyright Notice in lua.h
+*/
+
+#ifndef llex_h
+#define llex_h
+
+#include "lobject.h"
+#include "lzio.h"
+
+
+#define FIRST_RESERVED	257
+
+
+#if !defined(LUA_ENV)
+#define LUA_ENV		"_ENV"
+#endif
+
+
+/*
+* WARNING: if you change the order of this enumeration,
+* grep "ORDER RESERVED"
+*/
+enum RESERVED {
+  /* terminal symbols denoted by reserved words */
+  TK_AND = FIRST_RESERVED, TK_BREAK,
+  TK_DO, TK_ELSE, TK_ELSEIF, TK_END, TK_FALSE, TK_FOR, TK_FUNCTION,
+  TK_GOTO, TK_IF, TK_IN, TK_LOCAL, TK_NIL, TK_NOT, TK_OR, TK_REPEAT,
+  TK_RETURN, TK_THEN, TK_TRUE, TK_UNTIL, TK_WHILE,
+  /* other terminal symbols */
+  TK_IDIV, TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE,
+  TK_SHL, TK_SHR,
+  TK_DBCOLON, TK_EOS,
+  TK_FLT, TK_INT, TK_NAME, TK_STRING
+};
+
+/* number of reserved words */
+#define NUM_RESERVED	(cast(int, TK_WHILE-FIRST_RESERVED+1))
+
+
+typedef union {
+  lua_Number r;
+  lua_Integer i;
+  TString *ts;
+} SemInfo;  /* semantics information */
+
+
+typedef struct Token {
+  int token;
+  SemInfo seminfo;
+} Token;
+
+
+/* state of the lexer plus state of the parser when shared by all
+   functions */
+typedef struct LexState {
+  int current;  /* current character (charint) */
+  int linenumber;  /* input line counter */
+  int lastline;  /* line of last token 'consumed' */
+  Token t;  /* current token */
+  Token lookahead;  /* look ahead token */
+  struct FuncState *fs;  /* current function (parser) */
+  struct lua_State *L;
+  ZIO *z;  /* input stream */
+  Mbuffer *buff;  /* buffer for tokens */
+  Table *h;  /* to avoid collection/reuse strings */
+  struct Dyndata *dyd;  /* dynamic structures used by the parser */
+  TString *source;  /* current source name */
+  TString *envn;  /* environment variable name */
+} LexState;
+
+
+LUAI_FUNC void luaX_init (lua_State *L);
+LUAI_FUNC void luaX_setinput (lua_State *L, LexState *ls, ZIO *z,
+                              TString *source, int firstchar);
+LUAI_FUNC TString *luaX_newstring (LexState *ls, const char *str, size_t l);
+LUAI_FUNC void luaX_next (LexState *ls);
+LUAI_FUNC int luaX_lookahead (LexState *ls);
+LUAI_FUNC l_noret luaX_syntaxerror (LexState *ls, const char *s);
+LUAI_FUNC const char *luaX_token2str (LexState *ls, int token);
+
+
+#endif
diff --git a/src/llimits.h b/src/llimits.h
new file mode 100644
index 0000000..f21377f
--- /dev/null
+++ b/src/llimits.h
@@ -0,0 +1,323 @@
+/*
+** $Id: llimits.h,v 1.141 2015/11/19 19:16:22 roberto Exp $
+** Limits, basic types, and some other 'installation-dependent' definitions
+** See Copyright Notice in lua.h
+*/
+
+#ifndef llimits_h
+#define llimits_h
+
+
+#include <limits.h>
+#include <stddef.h>
+
+
+#include "lua.h"
+
+/*
+** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count
+** the total memory used by Lua (in bytes). Usually, 'size_t' and
+** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines.
+*/
+#if defined(LUAI_MEM)		/* { external definitions? */
+typedef LUAI_UMEM lu_mem;
+typedef LUAI_MEM l_mem;
+#elif LUAI_BITSINT >= 32	/* }{ */
+typedef size_t lu_mem;
+typedef ptrdiff_t l_mem;
+#else  /* 16-bit ints */	/* }{ */
+typedef unsigned long lu_mem;
+typedef long l_mem;
+#endif				/* } */
+
+
+/* chars used as small naturals (so that 'char' is reserved for characters) */
+typedef unsigned char lu_byte;
+
+
+/* maximum value for size_t */
+#define MAX_SIZET	((size_t)(~(size_t)0))
+
+/* maximum size visible for Lua (must be representable in a lua_Integer */
+#define MAX_SIZE	(sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \
+                          : (size_t)(LUA_MAXINTEGER))
+
+
+#define MAX_LUMEM	((lu_mem)(~(lu_mem)0))
+
+#define MAX_LMEM	((l_mem)(MAX_LUMEM >> 1))
+
+
+#define MAX_INT		INT_MAX  /* maximum value of an int */
+
+
+/*
+** conversion of pointer to unsigned integer:
+** this is for hashing only; there is no problem if the integer
+** cannot hold the whole pointer value
+*/
+#define point2uint(p)	((unsigned int)((size_t)(p) & UINT_MAX))
+
+
+
+/* type to ensure maximum alignment */
+#if defined(LUAI_USER_ALIGNMENT_T)
+typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
+#else
+typedef union {
+  lua_Number n;
+  double u;
+  void *s;
+  lua_Integer i;
+  long l;
+} L_Umaxalign;
+#endif
+
+
+
+/* types of 'usual argument conversions' for lua_Number and lua_Integer */
+typedef LUAI_UACNUMBER l_uacNumber;
+typedef LUAI_UACINT l_uacInt;
+
+
+/* internal assertions for in-house debugging */
+#if defined(lua_assert)
+#define check_exp(c,e)		(lua_assert(c), (e))
+/* to avoid problems with conditions too long */
+#define lua_longassert(c)	((c) ? (void)0 : lua_assert(0))
+#else
+#define lua_assert(c)		((void)0)
+#define check_exp(c,e)		(e)
+#define lua_longassert(c)	((void)0)
+#endif
+
+/*
+** assertion for checking API calls
+*/
+#if !defined(luai_apicheck)
+#define luai_apicheck(l,e)	lua_assert(e)
+#endif
+
+#define api_check(l,e,msg)	luai_apicheck(l,(e) && msg)
+
+
+/* macro to avoid warnings about unused variables */
+#if !defined(UNUSED)
+#define UNUSED(x)	((void)(x))
+#endif
+
+
+/* type casts (a macro highlights casts in the code) */
+#define cast(t, exp)	((t)(exp))
+
+#define cast_void(i)	cast(void, (i))
+#define cast_byte(i)	cast(lu_byte, (i))
+#define cast_num(i)	cast(lua_Number, (i))
+#define cast_int(i)	cast(int, (i))
+#define cast_uchar(i)	cast(unsigned char, (i))
+
+
+/* cast a signed lua_Integer to lua_Unsigned */
+#if !defined(l_castS2U)
+#define l_castS2U(i)	((lua_Unsigned)(i))
+#endif
+
+/*
+** cast a lua_Unsigned to a signed lua_Integer; this cast is
+** not strict ISO C, but two-complement architectures should
+** work fine.
+*/
+#if !defined(l_castU2S)
+#define l_castU2S(i)	((lua_Integer)(i))
+#endif
+
+
+/*
+** non-return type
+*/
+#if defined(__GNUC__)
+#define l_noret		void __attribute__((noreturn))
+#elif defined(_MSC_VER) && _MSC_VER >= 1200
+#define l_noret		void __declspec(noreturn)
+#else
+#define l_noret		void
+#endif
+
+
+
+/*
+** maximum depth for nested C calls and syntactical nested non-terminals
+** in a program. (Value must fit in an unsigned short int.)
+*/
+#if !defined(LUAI_MAXCCALLS)
+#define LUAI_MAXCCALLS		200
+#endif
+
+
+
+/*
+** type for virtual-machine instructions;
+** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
+*/
+#if LUAI_BITSINT >= 32
+typedef unsigned int Instruction;
+#else
+typedef unsigned long Instruction;
+#endif
+
+
+
+/*
+** Maximum length for short strings, that is, strings that are
+** internalized. (Cannot be smaller than reserved words or tags for
+** metamethods, as these strings must be internalized;
+** #("function") = 8, #("__newindex") = 10.)
+*/
+#if !defined(LUAI_MAXSHORTLEN)
+#define LUAI_MAXSHORTLEN	40
+#endif
+
+
+/*
+** Initial size for the string table (must be power of 2).
+** The Lua core alone registers ~50 strings (reserved words +
+** metaevent keys + a few others). Libraries would typically add
+** a few dozens more.
+*/
+#if !defined(MINSTRTABSIZE)
+#define MINSTRTABSIZE	128
+#endif
+
+
+/*
+** Size of cache for strings in the API. 'N' is the number of
+** sets (better be a prime) and "M" is the size of each set (M == 1
+** makes a direct cache.)
+*/
+#if !defined(STRCACHE_N)
+#define STRCACHE_N		53
+#define STRCACHE_M		2
+#endif
+
+
+/* minimum size for string buffer */
+#if !defined(LUA_MINBUFFER)
+#define LUA_MINBUFFER	32
+#endif
+
+
+/*
+** macros that are executed whenever program enters the Lua core
+** ('lua_lock') and leaves the core ('lua_unlock')
+*/
+#if !defined(lua_lock)
+#define lua_lock(L)	((void) 0)
+#define lua_unlock(L)	((void) 0)
+#endif
+
+/*
+** macro executed during Lua functions at points where the
+** function can yield.
+*/
+#if !defined(luai_threadyield)
+#define luai_threadyield(L)	{lua_unlock(L); lua_lock(L);}
+#endif
+
+
+/*
+** these macros allow user-specific actions on threads when you defined
+** LUAI_EXTRASPACE and need to do something extra when a thread is
+** created/deleted/resumed/yielded.
+*/
+#if !defined(luai_userstateopen)
+#define luai_userstateopen(L)		((void)L)
+#endif
+
+#if !defined(luai_userstateclose)
+#define luai_userstateclose(L)		((void)L)
+#endif
+
+#if !defined(luai_userstatethread)
+#define luai_userstatethread(L,L1)	((void)L)
+#endif
+
+#if !defined(luai_userstatefree)
+#define luai_userstatefree(L,L1)	((void)L)
+#endif
+
+#if !defined(luai_userstateresume)
+#define luai_userstateresume(L,n)	((void)L)
+#endif
+
+#if !defined(luai_userstateyield)
+#define luai_userstateyield(L,n)	((void)L)
+#endif
+
+
+
+/*
+** The luai_num* macros define the primitive operations over numbers.
+*/
+
+/* floor division (defined as 'floor(a/b)') */
+#if !defined(luai_numidiv)
+#define luai_numidiv(L,a,b)     ((void)L, l_floor(luai_numdiv(L,a,b)))
+#endif
+
+/* float division */
+#if !defined(luai_numdiv)
+#define luai_numdiv(L,a,b)      ((a)/(b))
+#endif
+
+/*
+** modulo: defined as 'a - floor(a/b)*b'; this definition gives NaN when
+** 'b' is huge, but the result should be 'a'. 'fmod' gives the result of
+** 'a - trunc(a/b)*b', and therefore must be corrected when 'trunc(a/b)
+** ~= floor(a/b)'. That happens when the division has a non-integer
+** negative result, which is equivalent to the test below.
+*/
+#if !defined(luai_nummod)
+#define luai_nummod(L,a,b,m)  \
+  { (m) = l_mathop(fmod)(a,b); if ((m)*(b) < 0) (m) += (b); }
+#endif
+
+/* exponentiation */
+#if !defined(luai_numpow)
+#define luai_numpow(L,a,b)      ((void)L, l_mathop(pow)(a,b))
+#endif
+
+/* the others are quite standard operations */
+#if !defined(luai_numadd)
+#define luai_numadd(L,a,b)      ((a)+(b))
+#define luai_numsub(L,a,b)      ((a)-(b))
+#define luai_nummul(L,a,b)      ((a)*(b))
+#define luai_numunm(L,a)        (-(a))
+#define luai_numeq(a,b)         ((a)==(b))
+#define luai_numlt(a,b)         ((a)<(b))
+#define luai_numle(a,b)         ((a)<=(b))
+#define luai_numisnan(a)        (!luai_numeq((a), (a)))
+#endif
+
+
+
+
+
+/*
+** macro to control inclusion of some hard tests on stack reallocation
+*/
+#if !defined(HARDSTACKTESTS)
+#define condmovestack(L,pre,pos)	((void)0)
+#else
+/* realloc stack keeping its size */
+#define condmovestack(L,pre,pos)  \
+	{ int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_); pos; }
+#endif
+
+#if !defined(HARDMEMTESTS)
+#define condchangemem(L,pre,pos)	((void)0)
+#else
+#define condchangemem(L,pre,pos)  \
+	{ if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } }
+#endif
+
+#endif
diff --git a/src/lmathlib.c b/src/lmathlib.c
new file mode 100644
index 0000000..94815f1
--- /dev/null
+++ b/src/lmathlib.c
@@ -0,0 +1,407 @@
+/*
+** $Id: lmathlib.c,v 1.117 2015/10/02 15:39:23 roberto Exp $
+** Standard mathematical library
+** See Copyright Notice in lua.h
+*/
+
+#define lmathlib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <stdlib.h>
+#include <math.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+#undef PI
+#define PI	(l_mathop(3.141592653589793238462643383279502884))
+
+
+#if !defined(l_rand)		/* { */
+#if defined(LUA_USE_POSIX)
+#define l_rand()	random()
+#define l_srand(x)	srandom(x)
+#define L_RANDMAX	2147483647	/* (2^31 - 1), following POSIX */
+#else
+#define l_rand()	rand()
+#define l_srand(x)	srand(x)
+#define L_RANDMAX	RAND_MAX
+#endif
+#endif				/* } */
+
+
+static int math_abs (lua_State *L) {
+  if (lua_isinteger(L, 1)) {
+    lua_Integer n = lua_tointeger(L, 1);
+    if (n < 0) n = (lua_Integer)(0u - (lua_Unsigned)n);
+    lua_pushinteger(L, n);
+  }
+  else
+    lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_sin (lua_State *L) {
+  lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_cos (lua_State *L) {
+  lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_tan (lua_State *L) {
+  lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_asin (lua_State *L) {
+  lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_acos (lua_State *L) {
+  lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_atan (lua_State *L) {
+  lua_Number y = luaL_checknumber(L, 1);
+  lua_Number x = luaL_optnumber(L, 2, 1);
+  lua_pushnumber(L, l_mathop(atan2)(y, x));
+  return 1;
+}
+
+
+static int math_toint (lua_State *L) {
+  int valid;
+  lua_Integer n = lua_tointegerx(L, 1, &valid);
+  if (valid)
+    lua_pushinteger(L, n);
+  else {
+    luaL_checkany(L, 1);
+    lua_pushnil(L);  /* value is not convertible to integer */
+  }
+  return 1;
+}
+
+
+static void pushnumint (lua_State *L, lua_Number d) {
+  lua_Integer n;
+  if (lua_numbertointeger(d, &n))  /* does 'd' fit in an integer? */
+    lua_pushinteger(L, n);  /* result is integer */
+  else
+    lua_pushnumber(L, d);  /* result is float */
+}
+
+
+static int math_floor (lua_State *L) {
+  if (lua_isinteger(L, 1))
+    lua_settop(L, 1);  /* integer is its own floor */
+  else {
+    lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1));
+    pushnumint(L, d);
+  }
+  return 1;
+}
+
+
+static int math_ceil (lua_State *L) {
+  if (lua_isinteger(L, 1))
+    lua_settop(L, 1);  /* integer is its own ceil */
+  else {
+    lua_Number d = l_mathop(ceil)(luaL_checknumber(L, 1));
+    pushnumint(L, d);
+  }
+  return 1;
+}
+
+
+static int math_fmod (lua_State *L) {
+  if (lua_isinteger(L, 1) && lua_isinteger(L, 2)) {
+    lua_Integer d = lua_tointeger(L, 2);
+    if ((lua_Unsigned)d + 1u <= 1u) {  /* special cases: -1 or 0 */
+      luaL_argcheck(L, d != 0, 2, "zero");
+      lua_pushinteger(L, 0);  /* avoid overflow with 0x80000... / -1 */
+    }
+    else
+      lua_pushinteger(L, lua_tointeger(L, 1) % d);
+  }
+  else
+    lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1),
+                                     luaL_checknumber(L, 2)));
+  return 1;
+}
+
+
+/*
+** next function does not use 'modf', avoiding problems with 'double*'
+** (which is not compatible with 'float*') when lua_Number is not
+** 'double'.
+*/
+static int math_modf (lua_State *L) {
+  if (lua_isinteger(L ,1)) {
+    lua_settop(L, 1);  /* number is its own integer part */
+    lua_pushnumber(L, 0);  /* no fractional part */
+  }
+  else {
+    lua_Number n = luaL_checknumber(L, 1);
+    /* integer part (rounds toward zero) */
+    lua_Number ip = (n < 0) ? l_mathop(ceil)(n) : l_mathop(floor)(n);
+    pushnumint(L, ip);
+    /* fractional part (test needed for inf/-inf) */
+    lua_pushnumber(L, (n == ip) ? l_mathop(0.0) : (n - ip));
+  }
+  return 2;
+}
+
+
+static int math_sqrt (lua_State *L) {
+  lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+
+static int math_ult (lua_State *L) {
+  lua_Integer a = luaL_checkinteger(L, 1);
+  lua_Integer b = luaL_checkinteger(L, 2);
+  lua_pushboolean(L, (lua_Unsigned)a < (lua_Unsigned)b);
+  return 1;
+}
+
+static int math_log (lua_State *L) {
+  lua_Number x = luaL_checknumber(L, 1);
+  lua_Number res;
+  if (lua_isnoneornil(L, 2))
+    res = l_mathop(log)(x);
+  else {
+    lua_Number base = luaL_checknumber(L, 2);
+#if !defined(LUA_USE_C89)
+    if (base == 2.0) res = l_mathop(log2)(x); else
+#endif
+    if (base == 10.0) res = l_mathop(log10)(x);
+    else res = l_mathop(log)(x)/l_mathop(log)(base);
+  }
+  lua_pushnumber(L, res);
+  return 1;
+}
+
+static int math_exp (lua_State *L) {
+  lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_deg (lua_State *L) {
+  lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI));
+  return 1;
+}
+
+static int math_rad (lua_State *L) {
+  lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0)));
+  return 1;
+}
+
+
+static int math_min (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  int imin = 1;  /* index of current minimum value */
+  int i;
+  luaL_argcheck(L, n >= 1, 1, "value expected");
+  for (i = 2; i <= n; i++) {
+    if (lua_compare(L, i, imin, LUA_OPLT))
+      imin = i;
+  }
+  lua_pushvalue(L, imin);
+  return 1;
+}
+
+
+static int math_max (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  int imax = 1;  /* index of current maximum value */
+  int i;
+  luaL_argcheck(L, n >= 1, 1, "value expected");
+  for (i = 2; i <= n; i++) {
+    if (lua_compare(L, imax, i, LUA_OPLT))
+      imax = i;
+  }
+  lua_pushvalue(L, imax);
+  return 1;
+}
+
+/*
+** This function uses 'double' (instead of 'lua_Number') to ensure that
+** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0'
+** will keep full precision (ensuring that 'r' is always less than 1.0.)
+*/
+static int math_random (lua_State *L) {
+  lua_Integer low, up;
+  double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0));
+  switch (lua_gettop(L)) {  /* check number of arguments */
+    case 0: {  /* no arguments */
+      lua_pushnumber(L, (lua_Number)r);  /* Number between 0 and 1 */
+      return 1;
+    }
+    case 1: {  /* only upper limit */
+      low = 1;
+      up = luaL_checkinteger(L, 1);
+      break;
+    }
+    case 2: {  /* lower and upper limits */
+      low = luaL_checkinteger(L, 1);
+      up = luaL_checkinteger(L, 2);
+      break;
+    }
+    default: return luaL_error(L, "wrong number of arguments");
+  }
+  /* random integer in the interval [low, up] */
+  luaL_argcheck(L, low <= up, 1, "interval is empty"); 
+  luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
+                   "interval too large");
+  r *= (double)(up - low) + 1.0;
+  lua_pushinteger(L, (lua_Integer)r + low);
+  return 1;
+}
+
+
+static int math_randomseed (lua_State *L) {
+  l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));
+  (void)l_rand(); /* discard first value to avoid undesirable correlations */
+  return 0;
+}
+
+
+static int math_type (lua_State *L) {
+  if (lua_type(L, 1) == LUA_TNUMBER) {
+      if (lua_isinteger(L, 1))
+        lua_pushliteral(L, "integer"); 
+      else
+        lua_pushliteral(L, "float"); 
+  }
+  else {
+    luaL_checkany(L, 1);
+    lua_pushnil(L);
+  }
+  return 1;
+}
+
+
+/*
+** {==================================================================
+** Deprecated functions (for compatibility only)
+** ===================================================================
+*/
+#if defined(LUA_COMPAT_MATHLIB)
+
+static int math_cosh (lua_State *L) {
+  lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_sinh (lua_State *L) {
+  lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_tanh (lua_State *L) {
+  lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+static int math_pow (lua_State *L) {
+  lua_Number x = luaL_checknumber(L, 1);
+  lua_Number y = luaL_checknumber(L, 2);
+  lua_pushnumber(L, l_mathop(pow)(x, y));
+  return 1;
+}
+
+static int math_frexp (lua_State *L) {
+  int e;
+  lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));
+  lua_pushinteger(L, e);
+  return 2;
+}
+
+static int math_ldexp (lua_State *L) {
+  lua_Number x = luaL_checknumber(L, 1);
+  int ep = (int)luaL_checkinteger(L, 2);
+  lua_pushnumber(L, l_mathop(ldexp)(x, ep));
+  return 1;
+}
+
+static int math_log10 (lua_State *L) {
+  lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));
+  return 1;
+}
+
+#endif
+/* }================================================================== */
+
+
+
+static const luaL_Reg mathlib[] = {
+  {"abs",   math_abs},
+  {"acos",  math_acos},
+  {"asin",  math_asin},
+  {"atan",  math_atan},
+  {"ceil",  math_ceil},
+  {"cos",   math_cos},
+  {"deg",   math_deg},
+  {"exp",   math_exp},
+  {"tointeger", math_toint},
+  {"floor", math_floor},
+  {"fmod",   math_fmod},
+  {"ult",   math_ult},
+  {"log",   math_log},
+  {"max",   math_max},
+  {"min",   math_min},
+  {"modf",   math_modf},
+  {"rad",   math_rad},
+  {"random",     math_random},
+  {"randomseed", math_randomseed},
+  {"sin",   math_sin},
+  {"sqrt",  math_sqrt},
+  {"tan",   math_tan},
+  {"type", math_type},
+#if defined(LUA_COMPAT_MATHLIB)
+  {"atan2", math_atan},
+  {"cosh",   math_cosh},
+  {"sinh",   math_sinh},
+  {"tanh",   math_tanh},
+  {"pow",   math_pow},
+  {"frexp", math_frexp},
+  {"ldexp", math_ldexp},
+  {"log10", math_log10},
+#endif
+  /* placeholders */
+  {"pi", NULL},
+  {"huge", NULL},
+  {"maxinteger", NULL},
+  {"mininteger", NULL},
+  {NULL, NULL}
+};
+
+
+/*
+** Open math library
+*/
+LUAMOD_API int luaopen_math (lua_State *L) {
+  luaL_newlib(L, mathlib);
+  lua_pushnumber(L, PI);
+  lua_setfield(L, -2, "pi");
+  lua_pushnumber(L, (lua_Number)HUGE_VAL);
+  lua_setfield(L, -2, "huge");
+  lua_pushinteger(L, LUA_MAXINTEGER);
+  lua_setfield(L, -2, "maxinteger");
+  lua_pushinteger(L, LUA_MININTEGER);
+  lua_setfield(L, -2, "mininteger");
+  return 1;
+}
+
diff --git a/src/lmem.c b/src/lmem.c
new file mode 100644
index 0000000..0a0476c
--- /dev/null
+++ b/src/lmem.c
@@ -0,0 +1,100 @@
+/*
+** $Id: lmem.c,v 1.91 2015/03/06 19:45:54 roberto Exp $
+** Interface to Memory Manager
+** See Copyright Notice in lua.h
+*/
+
+#define lmem_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+
+
+
+/*
+** About the realloc function:
+** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
+** ('osize' is the old size, 'nsize' is the new size)
+**
+** * frealloc(ud, NULL, x, s) creates a new block of size 's' (no
+** matter 'x').
+**
+** * frealloc(ud, p, x, 0) frees the block 'p'
+** (in this specific case, frealloc must return NULL);
+** particularly, frealloc(ud, NULL, 0, 0) does nothing
+** (which is equivalent to free(NULL) in ISO C)
+**
+** frealloc returns NULL if it cannot create or reallocate the area
+** (any reallocation to an equal or smaller size cannot fail!)
+*/
+
+
+
+#define MINSIZEARRAY	4
+
+
+void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
+                     int limit, const char *what) {
+  void *newblock;
+  int newsize;
+  if (*size >= limit/2) {  /* cannot double it? */
+    if (*size >= limit)  /* cannot grow even a little? */
+      luaG_runerror(L, "too many %s (limit is %d)", what, limit);
+    newsize = limit;  /* still have at least one free place */
+  }
+  else {
+    newsize = (*size)*2;
+    if (newsize < MINSIZEARRAY)
+      newsize = MINSIZEARRAY;  /* minimum size */
+  }
+  newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
+  *size = newsize;  /* update only when everything else is OK */
+  return newblock;
+}
+
+
+l_noret luaM_toobig (lua_State *L) {
+  luaG_runerror(L, "memory allocation error: block too big");
+}
+
+
+
+/*
+** generic allocation routine.
+*/
+void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
+  void *newblock;
+  global_State *g = G(L);
+  size_t realosize = (block) ? osize : 0;
+  lua_assert((realosize == 0) == (block == NULL));
+#if defined(HARDMEMTESTS)
+  if (nsize > realosize && g->gcrunning)
+    luaC_fullgc(L, 1);  /* force a GC whenever possible */
+#endif
+  newblock = (*g->frealloc)(g->ud, block, osize, nsize);
+  if (newblock == NULL && nsize > 0) {
+    lua_assert(nsize > realosize);  /* cannot fail when shrinking a block */
+    if (g->version) {  /* is state fully built? */
+      luaC_fullgc(L, 1);  /* try to free some memory... */
+      newblock = (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
+    }
+    if (newblock == NULL)
+      luaD_throw(L, LUA_ERRMEM);
+  }
+  lua_assert((nsize == 0) == (newblock == NULL));
+  g->GCdebt = (g->GCdebt + nsize) - realosize;
+  return newblock;
+}
+
diff --git a/src/lmem.h b/src/lmem.h
new file mode 100644
index 0000000..30f4848
--- /dev/null
+++ b/src/lmem.h
@@ -0,0 +1,69 @@
+/*
+** $Id: lmem.h,v 1.43 2014/12/19 17:26:14 roberto Exp $
+** Interface to Memory Manager
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lmem_h
+#define lmem_h
+
+
+#include <stddef.h>
+
+#include "llimits.h"
+#include "lua.h"
+
+
+/*
+** This macro reallocs a vector 'b' from 'on' to 'n' elements, where
+** each element has size 'e'. In case of arithmetic overflow of the
+** product 'n'*'e', it raises an error (calling 'luaM_toobig'). Because
+** 'e' is always constant, it avoids the runtime division MAX_SIZET/(e).
+**
+** (The macro is somewhat complex to avoid warnings:  The 'sizeof'
+** comparison avoids a runtime comparison when overflow cannot occur.
+** The compiler should be able to optimize the real test by itself, but
+** when it does it, it may give a warning about "comparison is always
+** false due to limited range of data type"; the +1 tricks the compiler,
+** avoiding this warning but also this optimization.)
+*/
+#define luaM_reallocv(L,b,on,n,e) \
+  (((sizeof(n) >= sizeof(size_t) && cast(size_t, (n)) + 1 > MAX_SIZET/(e)) \
+      ? luaM_toobig(L) : cast_void(0)) , \
+   luaM_realloc_(L, (b), (on)*(e), (n)*(e)))
+
+/*
+** Arrays of chars do not need any test
+*/
+#define luaM_reallocvchar(L,b,on,n)  \
+    cast(char *, luaM_realloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
+
+#define luaM_freemem(L, b, s)	luaM_realloc_(L, (b), (s), 0)
+#define luaM_free(L, b)		luaM_realloc_(L, (b), sizeof(*(b)), 0)
+#define luaM_freearray(L, b, n)   luaM_realloc_(L, (b), (n)*sizeof(*(b)), 0)
+
+#define luaM_malloc(L,s)	luaM_realloc_(L, NULL, 0, (s))
+#define luaM_new(L,t)		cast(t *, luaM_malloc(L, sizeof(t)))
+#define luaM_newvector(L,n,t) \
+		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
+
+#define luaM_newobject(L,tag,s)	luaM_realloc_(L, NULL, tag, (s))
+
+#define luaM_growvector(L,v,nelems,size,t,limit,e) \
+          if ((nelems)+1 > (size)) \
+            ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
+
+#define luaM_reallocvector(L, v,oldn,n,t) \
+   ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
+
+LUAI_FUNC l_noret luaM_toobig (lua_State *L);
+
+/* not to be called directly */
+LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
+                                                          size_t size);
+LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
+                               size_t size_elem, int limit,
+                               const char *what);
+
+#endif
+
diff --git a/src/loadlib.c b/src/loadlib.c
new file mode 100644
index 0000000..7911928
--- /dev/null
+++ b/src/loadlib.c
@@ -0,0 +1,787 @@
+/*
+** $Id: loadlib.c,v 1.127 2015/11/23 11:30:45 roberto Exp $
+** Dynamic library loader for Lua
+** See Copyright Notice in lua.h
+**
+** This module contains an implementation of loadlib for Unix systems
+** that have dlfcn, an implementation for Windows, and a stub for other
+** systems.
+*/
+
+#define loadlib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
+** variables that Lua check to set its paths.
+*/
+#if !defined(LUA_PATH_VAR)
+#define LUA_PATH_VAR	"LUA_PATH"
+#endif
+
+#if !defined(LUA_CPATH_VAR)
+#define LUA_CPATH_VAR	"LUA_CPATH"
+#endif
+
+#define LUA_PATHSUFFIX		"_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
+
+#define LUA_PATHVARVERSION		LUA_PATH_VAR LUA_PATHSUFFIX
+#define LUA_CPATHVARVERSION		LUA_CPATH_VAR LUA_PATHSUFFIX
+
+/*
+** LUA_PATH_SEP is the character that separates templates in a path.
+** LUA_PATH_MARK is the string that marks the substitution points in a
+** template.
+** LUA_EXEC_DIR in a Windows path is replaced by the executable's
+** directory.
+** LUA_IGMARK is a mark to ignore all before it when building the
+** luaopen_ function name.
+*/
+#if !defined (LUA_PATH_SEP)
+#define LUA_PATH_SEP		";"
+#endif
+#if !defined (LUA_PATH_MARK)
+#define LUA_PATH_MARK		"?"
+#endif
+#if !defined (LUA_EXEC_DIR)
+#define LUA_EXEC_DIR		"!"
+#endif
+#if !defined (LUA_IGMARK)
+#define LUA_IGMARK		"-"
+#endif
+
+
+/*
+** LUA_CSUBSEP is the character that replaces dots in submodule names
+** when searching for a C loader.
+** LUA_LSUBSEP is the character that replaces dots in submodule names
+** when searching for a Lua loader.
+*/
+#if !defined(LUA_CSUBSEP)
+#define LUA_CSUBSEP		LUA_DIRSEP
+#endif
+
+#if !defined(LUA_LSUBSEP)
+#define LUA_LSUBSEP		LUA_DIRSEP
+#endif
+
+
+/* prefix for open functions in C libraries */
+#define LUA_POF		"luaopen_"
+
+/* separator for open functions in C libraries */
+#define LUA_OFSEP	"_"
+
+
+/*
+** unique key for table in the registry that keeps handles
+** for all loaded C libraries
+*/
+static const int CLIBS = 0;
+
+#define LIB_FAIL	"open"
+
+#define setprogdir(L)		((void)0)
+
+
+/*
+** system-dependent functions
+*/
+
+/*
+** unload library 'lib'
+*/
+static void lsys_unloadlib (void *lib);
+
+/*
+** load C library in file 'path'. If 'seeglb', load with all names in
+** the library global.
+** Returns the library; in case of error, returns NULL plus an
+** error string in the stack.
+*/
+static void *lsys_load (lua_State *L, const char *path, int seeglb);
+
+/*
+** Try to find a function named 'sym' in library 'lib'.
+** Returns the function; in case of error, returns NULL plus an
+** error string in the stack.
+*/
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
+
+
+
+
+#if defined(LUA_USE_DLOPEN)	/* { */
+/*
+** {========================================================================
+** This is an implementation of loadlib based on the dlfcn interface.
+** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
+** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
+** as an emulation layer on top of native functions.
+** =========================================================================
+*/
+
+#include <dlfcn.h>
+
+/*
+** Macro to convert pointer-to-void* to pointer-to-function. This cast
+** is undefined according to ISO C, but POSIX assumes that it works.
+** (The '__extension__' in gnu compilers is only to avoid warnings.)
+*/
+#if defined(__GNUC__)
+#define cast_func(p) (__extension__ (lua_CFunction)(p))
+#else
+#define cast_func(p) ((lua_CFunction)(p))
+#endif
+
+
+static void lsys_unloadlib (void *lib) {
+  dlclose(lib);
+}
+
+
+static void *lsys_load (lua_State *L, const char *path, int seeglb) {
+  void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
+  if (lib == NULL) lua_pushstring(L, dlerror());
+  return lib;
+}
+
+
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
+  lua_CFunction f = cast_func(dlsym(lib, sym));
+  if (f == NULL) lua_pushstring(L, dlerror());
+  return f;
+}
+
+/* }====================================================== */
+
+
+
+#elif defined(LUA_DL_DLL)	/* }{ */
+/*
+** {======================================================================
+** This is an implementation of loadlib for Windows using native functions.
+** =======================================================================
+*/
+
+#include <windows.h>
+
+#undef setprogdir
+
+/*
+** optional flags for LoadLibraryEx
+*/
+#if !defined(LUA_LLE_FLAGS)
+#define LUA_LLE_FLAGS	0
+#endif
+
+
+static void setprogdir (lua_State *L) {
+  char buff[MAX_PATH + 1];
+  char *lb;
+  DWORD nsize = sizeof(buff)/sizeof(char);
+  DWORD n = GetModuleFileNameA(NULL, buff, nsize);
+  if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
+    luaL_error(L, "unable to get ModuleFileName");
+  else {
+    *lb = '\0';
+    luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
+    lua_remove(L, -2);  /* remove original string */
+  }
+}
+
+
+static void pusherror (lua_State *L) {
+  int error = GetLastError();
+  char buffer[128];
+  if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
+      NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
+    lua_pushstring(L, buffer);
+  else
+    lua_pushfstring(L, "system error %d\n", error);
+}
+
+static void lsys_unloadlib (void *lib) {
+  FreeLibrary((HMODULE)lib);
+}
+
+
+static void *lsys_load (lua_State *L, const char *path, int seeglb) {
+  HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
+  (void)(seeglb);  /* not used: symbols are 'global' by default */
+  if (lib == NULL) pusherror(L);
+  return lib;
+}
+
+
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
+  lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
+  if (f == NULL) pusherror(L);
+  return f;
+}
+
+/* }====================================================== */
+
+
+#else				/* }{ */
+/*
+** {======================================================
+** Fallback for other systems
+** =======================================================
+*/
+
+#undef LIB_FAIL
+#define LIB_FAIL	"absent"
+
+
+#define DLMSG	"dynamic libraries not enabled; check your Lua installation"
+
+
+static void lsys_unloadlib (void *lib) {
+  (void)(lib);  /* not used */
+}
+
+
+static void *lsys_load (lua_State *L, const char *path, int seeglb) {
+  (void)(path); (void)(seeglb);  /* not used */
+  lua_pushliteral(L, DLMSG);
+  return NULL;
+}
+
+
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
+  (void)(lib); (void)(sym);  /* not used */
+  lua_pushliteral(L, DLMSG);
+  return NULL;
+}
+
+/* }====================================================== */
+#endif				/* } */
+
+
+/*
+** return registry.CLIBS[path]
+*/
+static void *checkclib (lua_State *L, const char *path) {
+  void *plib;
+  lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
+  lua_getfield(L, -1, path);
+  plib = lua_touserdata(L, -1);  /* plib = CLIBS[path] */
+  lua_pop(L, 2);  /* pop CLIBS table and 'plib' */
+  return plib;
+}
+
+
+/*
+** registry.CLIBS[path] = plib        -- for queries
+** registry.CLIBS[#CLIBS + 1] = plib  -- also keep a list of all libraries
+*/
+static void addtoclib (lua_State *L, const char *path, void *plib) {
+  lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
+  lua_pushlightuserdata(L, plib);
+  lua_pushvalue(L, -1);
+  lua_setfield(L, -3, path);  /* CLIBS[path] = plib */
+  lua_rawseti(L, -2, luaL_len(L, -2) + 1);  /* CLIBS[#CLIBS + 1] = plib */
+  lua_pop(L, 1);  /* pop CLIBS table */
+}
+
+
+/*
+** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
+** handles in list CLIBS
+*/
+static int gctm (lua_State *L) {
+  lua_Integer n = luaL_len(L, 1);
+  for (; n >= 1; n--) {  /* for each handle, in reverse order */
+    lua_rawgeti(L, 1, n);  /* get handle CLIBS[n] */
+    lsys_unloadlib(lua_touserdata(L, -1));
+    lua_pop(L, 1);  /* pop handle */
+  }
+  return 0;
+}
+
+
+
+/* error codes for 'lookforfunc' */
+#define ERRLIB		1
+#define ERRFUNC		2
+
+/*
+** Look for a C function named 'sym' in a dynamically loaded library
+** 'path'.
+** First, check whether the library is already loaded; if not, try
+** to load it.
+** Then, if 'sym' is '*', return true (as library has been loaded).
+** Otherwise, look for symbol 'sym' in the library and push a
+** C function with that symbol.
+** Return 0 and 'true' or a function in the stack; in case of
+** errors, return an error code and an error message in the stack.
+*/
+static int lookforfunc (lua_State *L, const char *path, const char *sym) {
+  void *reg = checkclib(L, path);  /* check loaded C libraries */
+  if (reg == NULL) {  /* must load library? */
+    reg = lsys_load(L, path, *sym == '*');  /* global symbols if 'sym'=='*' */
+    if (reg == NULL) return ERRLIB;  /* unable to load library */
+    addtoclib(L, path, reg);
+  }
+  if (*sym == '*') {  /* loading only library (no function)? */
+    lua_pushboolean(L, 1);  /* return 'true' */
+    return 0;  /* no errors */
+  }
+  else {
+    lua_CFunction f = lsys_sym(L, reg, sym);
+    if (f == NULL)
+      return ERRFUNC;  /* unable to find function */
+    lua_pushcfunction(L, f);  /* else create new function */
+    return 0;  /* no errors */
+  }
+}
+
+
+static int ll_loadlib (lua_State *L) {
+  const char *path = luaL_checkstring(L, 1);
+  const char *init = luaL_checkstring(L, 2);
+  int stat = lookforfunc(L, path, init);
+  if (stat == 0)  /* no errors? */
+    return 1;  /* return the loaded function */
+  else {  /* error; error message is on stack top */
+    lua_pushnil(L);
+    lua_insert(L, -2);
+    lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
+    return 3;  /* return nil, error message, and where */
+  }
+}
+
+
+
+/*
+** {======================================================
+** 'require' function
+** =======================================================
+*/
+
+
+static int readable (const char *filename) {
+  FILE *f = fopen(filename, "r");  /* try to open file */
+  if (f == NULL) return 0;  /* open failed */
+  fclose(f);
+  return 1;
+}
+
+
+static const char *pushnexttemplate (lua_State *L, const char *path) {
+  const char *l;
+  while (*path == *LUA_PATH_SEP) path++;  /* skip separators */
+  if (*path == '\0') return NULL;  /* no more templates */
+  l = strchr(path, *LUA_PATH_SEP);  /* find next separator */
+  if (l == NULL) l = path + strlen(path);
+  lua_pushlstring(L, path, l - path);  /* template */
+  return l;
+}
+
+
+static const char *searchpath (lua_State *L, const char *name,
+                                             const char *path,
+                                             const char *sep,
+                                             const char *dirsep) {
+  luaL_Buffer msg;  /* to build error message */
+  luaL_buffinit(L, &msg);
+  if (*sep != '\0')  /* non-empty separator? */
+    name = luaL_gsub(L, name, sep, dirsep);  /* replace it by 'dirsep' */
+  while ((path = pushnexttemplate(L, path)) != NULL) {
+    const char *filename = luaL_gsub(L, lua_tostring(L, -1),
+                                     LUA_PATH_MARK, name);
+    lua_remove(L, -2);  /* remove path template */
+    if (readable(filename))  /* does file exist and is readable? */
+      return filename;  /* return that file name */
+    lua_pushfstring(L, "\n\tno file '%s'", filename);
+    lua_remove(L, -2);  /* remove file name */
+    luaL_addvalue(&msg);  /* concatenate error msg. entry */
+  }
+  luaL_pushresult(&msg);  /* create error message */
+  return NULL;  /* not found */
+}
+
+
+static int ll_searchpath (lua_State *L) {
+  const char *f = searchpath(L, luaL_checkstring(L, 1),
+                                luaL_checkstring(L, 2),
+                                luaL_optstring(L, 3, "."),
+                                luaL_optstring(L, 4, LUA_DIRSEP));
+  if (f != NULL) return 1;
+  else {  /* error message is on top of the stack */
+    lua_pushnil(L);
+    lua_insert(L, -2);
+    return 2;  /* return nil + error message */
+  }
+}
+
+
+static const char *findfile (lua_State *L, const char *name,
+                                           const char *pname,
+                                           const char *dirsep) {
+  const char *path;
+  lua_getfield(L, lua_upvalueindex(1), pname);
+  path = lua_tostring(L, -1);
+  if (path == NULL)
+    luaL_error(L, "'package.%s' must be a string", pname);
+  return searchpath(L, name, path, ".", dirsep);
+}
+
+
+static int checkload (lua_State *L, int stat, const char *filename) {
+  if (stat) {  /* module loaded successfully? */
+    lua_pushstring(L, filename);  /* will be 2nd argument to module */
+    return 2;  /* return open function and file name */
+  }
+  else
+    return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s",
+                          lua_tostring(L, 1), filename, lua_tostring(L, -1));
+}
+
+
+static int searcher_Lua (lua_State *L) {
+  const char *filename;
+  const char *name = luaL_checkstring(L, 1);
+  filename = findfile(L, name, "path", LUA_LSUBSEP);
+  if (filename == NULL) return 1;  /* module not found in this path */
+  return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
+}
+
+
+/*
+** Try to find a load function for module 'modname' at file 'filename'.
+** First, change '.' to '_' in 'modname'; then, if 'modname' has
+** the form X-Y (that is, it has an "ignore mark"), build a function
+** name "luaopen_X" and look for it. (For compatibility, if that
+** fails, it also tries "luaopen_Y".) If there is no ignore mark,
+** look for a function named "luaopen_modname".
+*/
+static int loadfunc (lua_State *L, const char *filename, const char *modname) {
+  const char *openfunc;
+  const char *mark;
+  modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
+  mark = strchr(modname, *LUA_IGMARK);
+  if (mark) {
+    int stat;
+    openfunc = lua_pushlstring(L, modname, mark - modname);
+    openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
+    stat = lookforfunc(L, filename, openfunc);
+    if (stat != ERRFUNC) return stat;
+    modname = mark + 1;  /* else go ahead and try old-style name */
+  }
+  openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
+  return lookforfunc(L, filename, openfunc);
+}
+
+
+static int searcher_C (lua_State *L) {
+  const char *name = luaL_checkstring(L, 1);
+  const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
+  if (filename == NULL) return 1;  /* module not found in this path */
+  return checkload(L, (loadfunc(L, filename, name) == 0), filename);
+}
+
+
+static int searcher_Croot (lua_State *L) {
+  const char *filename;
+  const char *name = luaL_checkstring(L, 1);
+  const char *p = strchr(name, '.');
+  int stat;
+  if (p == NULL) return 0;  /* is root */
+  lua_pushlstring(L, name, p - name);
+  filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
+  if (filename == NULL) return 1;  /* root not found */
+  if ((stat = loadfunc(L, filename, name)) != 0) {
+    if (stat != ERRFUNC)
+      return checkload(L, 0, filename);  /* real error */
+    else {  /* open function not found */
+      lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename);
+      return 1;
+    }
+  }
+  lua_pushstring(L, filename);  /* will be 2nd argument to module */
+  return 2;
+}
+
+
+static int searcher_preload (lua_State *L) {
+  const char *name = luaL_checkstring(L, 1);
+  lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
+  if (lua_getfield(L, -1, name) == LUA_TNIL)  /* not found? */
+    lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
+  return 1;
+}
+
+
+static void findloader (lua_State *L, const char *name) {
+  int i;
+  luaL_Buffer msg;  /* to build error message */
+  luaL_buffinit(L, &msg);
+  /* push 'package.searchers' to index 3 in the stack */
+  if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
+    luaL_error(L, "'package.searchers' must be a table");
+  /*  iterate over available searchers to find a loader */
+  for (i = 1; ; i++) {
+    if (lua_rawgeti(L, 3, i) == LUA_TNIL) {  /* no more searchers? */
+      lua_pop(L, 1);  /* remove nil */
+      luaL_pushresult(&msg);  /* create error message */
+      luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
+    }
+    lua_pushstring(L, name);
+    lua_call(L, 1, 2);  /* call it */
+    if (lua_isfunction(L, -2))  /* did it find a loader? */
+      return;  /* module loader found */
+    else if (lua_isstring(L, -2)) {  /* searcher returned error message? */
+      lua_pop(L, 1);  /* remove extra return */
+      luaL_addvalue(&msg);  /* concatenate error message */
+    }
+    else
+      lua_pop(L, 2);  /* remove both returns */
+  }
+}
+
+
+static int ll_require (lua_State *L) {
+  const char *name = luaL_checkstring(L, 1);
+  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
+  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_getfield(L, 2, name);  /* _LOADED[name] */
+  if (lua_toboolean(L, -1))  /* is it there? */
+    return 1;  /* package is already loaded */
+  /* else must load package */
+  lua_pop(L, 1);  /* remove 'getfield' result */
+  findloader(L, name);
+  lua_pushstring(L, name);  /* pass name as argument to module loader */
+  lua_insert(L, -2);  /* name is 1st argument (before search data) */
+  lua_call(L, 2, 1);  /* run loader to load module */
+  if (!lua_isnil(L, -1))  /* non-nil return? */
+    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
+  if (lua_getfield(L, 2, name) == LUA_TNIL) {   /* module set no value? */
+    lua_pushboolean(L, 1);  /* use true as result */
+    lua_pushvalue(L, -1);  /* extra copy to be returned */
+    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
+  }
+  return 1;
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** 'module' function
+** =======================================================
+*/
+#if defined(LUA_COMPAT_MODULE)
+
+/*
+** changes the environment variable of calling function
+*/
+static void set_env (lua_State *L) {
+  lua_Debug ar;
+  if (lua_getstack(L, 1, &ar) == 0 ||
+      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
+      lua_iscfunction(L, -1))
+    luaL_error(L, "'module' not called from a Lua function");
+  lua_pushvalue(L, -2);  /* copy new environment table to top */
+  lua_setupvalue(L, -2, 1);
+  lua_pop(L, 1);  /* remove function */
+}
+
+
+static void dooptions (lua_State *L, int n) {
+  int i;
+  for (i = 2; i <= n; i++) {
+    if (lua_isfunction(L, i)) {  /* avoid 'calling' extra info. */
+      lua_pushvalue(L, i);  /* get option (a function) */
+      lua_pushvalue(L, -2);  /* module */
+      lua_call(L, 1, 0);
+    }
+  }
+}
+
+
+static void modinit (lua_State *L, const char *modname) {
+  const char *dot;
+  lua_pushvalue(L, -1);
+  lua_setfield(L, -2, "_M");  /* module._M = module */
+  lua_pushstring(L, modname);
+  lua_setfield(L, -2, "_NAME");
+  dot = strrchr(modname, '.');  /* look for last dot in module name */
+  if (dot == NULL) dot = modname;
+  else dot++;
+  /* set _PACKAGE as package name (full module name minus last part) */
+  lua_pushlstring(L, modname, dot - modname);
+  lua_setfield(L, -2, "_PACKAGE");
+}
+
+
+static int ll_module (lua_State *L) {
+  const char *modname = luaL_checkstring(L, 1);
+  int lastarg = lua_gettop(L);  /* last parameter */
+  luaL_pushmodule(L, modname, 1);  /* get/create module table */
+  /* check whether table already has a _NAME field */
+  if (lua_getfield(L, -1, "_NAME") != LUA_TNIL)
+    lua_pop(L, 1);  /* table is an initialized module */
+  else {  /* no; initialize it */
+    lua_pop(L, 1);
+    modinit(L, modname);
+  }
+  lua_pushvalue(L, -1);
+  set_env(L);
+  dooptions(L, lastarg);
+  return 1;
+}
+
+
+static int ll_seeall (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  if (!lua_getmetatable(L, 1)) {
+    lua_createtable(L, 0, 1); /* create new metatable */
+    lua_pushvalue(L, -1);
+    lua_setmetatable(L, 1);
+  }
+  lua_pushglobaltable(L);
+  lua_setfield(L, -2, "__index");  /* mt.__index = _G */
+  return 0;
+}
+
+#endif
+/* }====================================================== */
+
+
+
+/* auxiliary mark (for internal use) */
+#define AUXMARK		"\1"
+
+
+/*
+** return registry.LUA_NOENV as a boolean
+*/
+static int noenv (lua_State *L) {
+  int b;
+  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
+  b = lua_toboolean(L, -1);
+  lua_pop(L, 1);  /* remove value */
+  return b;
+}
+
+
+static void setpath (lua_State *L, const char *fieldname, const char *envname1,
+                                   const char *envname2, const char *def) {
+  const char *path = getenv(envname1);
+  if (path == NULL)  /* no environment variable? */
+    path = getenv(envname2);  /* try alternative name */
+  if (path == NULL || noenv(L))  /* no environment variable? */
+    lua_pushstring(L, def);  /* use default */
+  else {
+    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
+    path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
+                              LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
+    luaL_gsub(L, path, AUXMARK, def);
+    lua_remove(L, -2);
+  }
+  setprogdir(L);
+  lua_setfield(L, -2, fieldname);
+}
+
+
+static const luaL_Reg pk_funcs[] = {
+  {"loadlib", ll_loadlib},
+  {"searchpath", ll_searchpath},
+#if defined(LUA_COMPAT_MODULE)
+  {"seeall", ll_seeall},
+#endif
+  /* placeholders */
+  {"preload", NULL},
+  {"cpath", NULL},
+  {"path", NULL},
+  {"searchers", NULL},
+  {"loaded", NULL},
+  {NULL, NULL}
+};
+
+
+static const luaL_Reg ll_funcs[] = {
+#if defined(LUA_COMPAT_MODULE)
+  {"module", ll_module},
+#endif
+  {"require", ll_require},
+  {NULL, NULL}
+};
+
+
+static void createsearcherstable (lua_State *L) {
+  static const lua_CFunction searchers[] =
+    {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
+  int i;
+  /* create 'searchers' table */
+  lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
+  /* fill it with predefined searchers */
+  for (i=0; searchers[i] != NULL; i++) {
+    lua_pushvalue(L, -2);  /* set 'package' as upvalue for all searchers */
+    lua_pushcclosure(L, searchers[i], 1);
+    lua_rawseti(L, -2, i+1);
+  }
+#if defined(LUA_COMPAT_LOADERS)
+  lua_pushvalue(L, -1);  /* make a copy of 'searchers' table */
+  lua_setfield(L, -3, "loaders");  /* put it in field 'loaders' */
+#endif
+  lua_setfield(L, -2, "searchers");  /* put it in field 'searchers' */
+}
+
+
+/*
+** create table CLIBS to keep track of loaded C libraries,
+** setting a finalizer to close all libraries when closing state.
+*/
+static void createclibstable (lua_State *L) {
+  lua_newtable(L);  /* create CLIBS table */
+  lua_createtable(L, 0, 1);  /* create metatable for CLIBS */
+  lua_pushcfunction(L, gctm);
+  lua_setfield(L, -2, "__gc");  /* set finalizer for CLIBS table */
+  lua_setmetatable(L, -2);
+  lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS);  /* set CLIBS table in registry */
+}
+
+
+LUAMOD_API int luaopen_package (lua_State *L) {
+  createclibstable(L);
+  luaL_newlib(L, pk_funcs);  /* create 'package' table */
+  createsearcherstable(L);
+  /* set field 'path' */
+  setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT);
+  /* set field 'cpath' */
+  setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
+  /* store config information */
+  lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
+                     LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
+  lua_setfield(L, -2, "config");
+  /* set field 'loaded' */
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_setfield(L, -2, "loaded");
+  /* set field 'preload' */
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
+  lua_setfield(L, -2, "preload");
+  lua_pushglobaltable(L);
+  lua_pushvalue(L, -2);  /* set 'package' as upvalue for next lib */
+  luaL_setfuncs(L, ll_funcs, 1);  /* open lib into global table */
+  lua_pop(L, 1);  /* pop global table */
+  return 1;  /* return 'package' table */
+}
+
diff --git a/src/lobject.c b/src/lobject.c
new file mode 100644
index 0000000..a44b385
--- /dev/null
+++ b/src/lobject.c
@@ -0,0 +1,521 @@
+/*
+** $Id: lobject.c,v 2.111 2016/05/20 14:07:48 roberto Exp $
+** Some generic functions over Lua objects
+** See Copyright Notice in lua.h
+*/
+
+#define lobject_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <locale.h>
+#include <math.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lctype.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "lvm.h"
+
+
+
+LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
+
+
+/*
+** converts an integer to a "floating point byte", represented as
+** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
+** eeeee != 0 and (xxx) otherwise.
+*/
+int luaO_int2fb (unsigned int x) {
+  int e = 0;  /* exponent */
+  if (x < 8) return x;
+  while (x >= (8 << 4)) {  /* coarse steps */
+    x = (x + 0xf) >> 4;  /* x = ceil(x / 16) */
+    e += 4;
+  }
+  while (x >= (8 << 1)) {  /* fine steps */
+    x = (x + 1) >> 1;  /* x = ceil(x / 2) */
+    e++;
+  }
+  return ((e+1) << 3) | (cast_int(x) - 8);
+}
+
+
+/* converts back */
+int luaO_fb2int (int x) {
+  return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
+}
+
+
+/*
+** Computes ceil(log2(x))
+*/
+int luaO_ceillog2 (unsigned int x) {
+  static const lu_byte log_2[256] = {  /* log_2[i] = ceil(log2(i - 1)) */
+    0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
+  };
+  int l = 0;
+  x--;
+  while (x >= 256) { l += 8; x >>= 8; }
+  return l + log_2[x];
+}
+
+
+static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
+                                                   lua_Integer v2) {
+  switch (op) {
+    case LUA_OPADD: return intop(+, v1, v2);
+    case LUA_OPSUB:return intop(-, v1, v2);
+    case LUA_OPMUL:return intop(*, v1, v2);
+    case LUA_OPMOD: return luaV_mod(L, v1, v2);
+    case LUA_OPIDIV: return luaV_div(L, v1, v2);
+    case LUA_OPBAND: return intop(&, v1, v2);
+    case LUA_OPBOR: return intop(|, v1, v2);
+    case LUA_OPBXOR: return intop(^, v1, v2);
+    case LUA_OPSHL: return luaV_shiftl(v1, v2);
+    case LUA_OPSHR: return luaV_shiftl(v1, -v2);
+    case LUA_OPUNM: return intop(-, 0, v1);
+    case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
+    default: lua_assert(0); return 0;
+  }
+}
+
+
+static lua_Number numarith (lua_State *L, int op, lua_Number v1,
+                                                  lua_Number v2) {
+  switch (op) {
+    case LUA_OPADD: return luai_numadd(L, v1, v2);
+    case LUA_OPSUB: return luai_numsub(L, v1, v2);
+    case LUA_OPMUL: return luai_nummul(L, v1, v2);
+    case LUA_OPDIV: return luai_numdiv(L, v1, v2);
+    case LUA_OPPOW: return luai_numpow(L, v1, v2);
+    case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
+    case LUA_OPUNM: return luai_numunm(L, v1);
+    case LUA_OPMOD: {
+      lua_Number m;
+      luai_nummod(L, v1, v2, m);
+      return m;
+    }
+    default: lua_assert(0); return 0;
+  }
+}
+
+
+void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
+                 TValue *res) {
+  switch (op) {
+    case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
+    case LUA_OPSHL: case LUA_OPSHR:
+    case LUA_OPBNOT: {  /* operate only on integers */
+      lua_Integer i1; lua_Integer i2;
+      if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
+        setivalue(res, intarith(L, op, i1, i2));
+        return;
+      }
+      else break;  /* go to the end */
+    }
+    case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */
+      lua_Number n1; lua_Number n2;
+      if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
+        setfltvalue(res, numarith(L, op, n1, n2));
+        return;
+      }
+      else break;  /* go to the end */
+    }
+    default: {  /* other operations */
+      lua_Number n1; lua_Number n2;
+      if (ttisinteger(p1) && ttisinteger(p2)) {
+        setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
+        return;
+      }
+      else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
+        setfltvalue(res, numarith(L, op, n1, n2));
+        return;
+      }
+      else break;  /* go to the end */
+    }
+  }
+  /* could not perform raw operation; try metamethod */
+  lua_assert(L != NULL);  /* should not fail when folding (compile time) */
+  luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
+}
+
+
+int luaO_hexavalue (int c) {
+  if (lisdigit(c)) return c - '0';
+  else return (ltolower(c) - 'a') + 10;
+}
+
+
+static int isneg (const char **s) {
+  if (**s == '-') { (*s)++; return 1; }
+  else if (**s == '+') (*s)++;
+  return 0;
+}
+
+
+
+/*
+** {==================================================================
+** Lua's implementation for 'lua_strx2number'
+** ===================================================================
+*/
+
+#if !defined(lua_strx2number)
+
+/* maximum number of significant digits to read (to avoid overflows
+   even with single floats) */
+#define MAXSIGDIG	30
+
+/*
+** convert an hexadecimal numeric string to a number, following
+** C99 specification for 'strtod'
+*/
+static lua_Number lua_strx2number (const char *s, char **endptr) {
+  int dot = lua_getlocaledecpoint();
+  lua_Number r = 0.0;  /* result (accumulator) */
+  int sigdig = 0;  /* number of significant digits */
+  int nosigdig = 0;  /* number of non-significant digits */
+  int e = 0;  /* exponent correction */
+  int neg;  /* 1 if number is negative */
+  int hasdot = 0;  /* true after seen a dot */
+  *endptr = cast(char *, s);  /* nothing is valid yet */
+  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
+  neg = isneg(&s);  /* check signal */
+  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
+    return 0.0;  /* invalid format (no '0x') */
+  for (s += 2; ; s++) {  /* skip '0x' and read numeral */
+    if (*s == dot) {
+      if (hasdot) break;  /* second dot? stop loop */
+      else hasdot = 1;
+    }
+    else if (lisxdigit(cast_uchar(*s))) {
+      if (sigdig == 0 && *s == '0')  /* non-significant digit (zero)? */
+        nosigdig++;
+      else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
+          r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
+      else e++; /* too many digits; ignore, but still count for exponent */
+      if (hasdot) e--;  /* decimal digit? correct exponent */
+    }
+    else break;  /* neither a dot nor a digit */
+  }
+  if (nosigdig + sigdig == 0)  /* no digits? */
+    return 0.0;  /* invalid format */
+  *endptr = cast(char *, s);  /* valid up to here */
+  e *= 4;  /* each digit multiplies/divides value by 2^4 */
+  if (*s == 'p' || *s == 'P') {  /* exponent part? */
+    int exp1 = 0;  /* exponent value */
+    int neg1;  /* exponent signal */
+    s++;  /* skip 'p' */
+    neg1 = isneg(&s);  /* signal */
+    if (!lisdigit(cast_uchar(*s)))
+      return 0.0;  /* invalid; must have at least one digit */
+    while (lisdigit(cast_uchar(*s)))  /* read exponent */
+      exp1 = exp1 * 10 + *(s++) - '0';
+    if (neg1) exp1 = -exp1;
+    e += exp1;
+    *endptr = cast(char *, s);  /* valid up to here */
+  }
+  if (neg) r = -r;
+  return l_mathop(ldexp)(r, e);
+}
+
+#endif
+/* }====================================================== */
+
+
+/* maximum length of a numeral */
+#if !defined (L_MAXLENNUM)
+#define L_MAXLENNUM	200
+#endif
+
+static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
+  char *endptr;
+  *result = (mode == 'x') ? lua_strx2number(s, &endptr)  /* try to convert */
+                          : lua_str2number(s, &endptr);
+  if (endptr == s) return NULL;  /* nothing recognized? */
+  while (lisspace(cast_uchar(*endptr))) endptr++;  /* skip trailing spaces */
+  return (*endptr == '\0') ? endptr : NULL;  /* OK if no trailing characters */
+}
+
+
+/*
+** Convert string 's' to a Lua number (put in 'result'). Return NULL
+** on fail or the address of the ending '\0' on success.
+** 'pmode' points to (and 'mode' contains) special things in the string:
+** - 'x'/'X' means an hexadecimal numeral
+** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
+** - '.' just optimizes the search for the common case (nothing special)
+** This function accepts both the current locale or a dot as the radix
+** mark. If the convertion fails, it may mean number has a dot but
+** locale accepts something else. In that case, the code copies 's'
+** to a buffer (because 's' is read-only), changes the dot to the
+** current locale radix mark, and tries to convert again.
+*/
+static const char *l_str2d (const char *s, lua_Number *result) {
+  const char *endptr;
+  const char *pmode = strpbrk(s, ".xXnN");
+  int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
+  if (mode == 'n')  /* reject 'inf' and 'nan' */
+    return NULL;
+  endptr = l_str2dloc(s, result, mode);  /* try to convert */
+  if (endptr == NULL) {  /* failed? may be a different locale */
+    char buff[L_MAXLENNUM + 1];
+    char *pdot = strchr(s, '.');
+    if (strlen(s) > L_MAXLENNUM || pdot == NULL)
+      return NULL;  /* string too long or no dot; fail */
+    strcpy(buff, s);  /* copy string to buffer */
+    buff[pdot - s] = lua_getlocaledecpoint();  /* correct decimal point */
+    endptr = l_str2dloc(buff, result, mode);  /* try again */
+    if (endptr != NULL)
+      endptr = s + (endptr - buff);  /* make relative to 's' */
+  }
+  return endptr;
+}
+
+
+#define MAXBY10		cast(lua_Unsigned, LUA_MAXINTEGER / 10)
+#define MAXLASTD	cast_int(LUA_MAXINTEGER % 10)
+
+static const char *l_str2int (const char *s, lua_Integer *result) {
+  lua_Unsigned a = 0;
+  int empty = 1;
+  int neg;
+  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
+  neg = isneg(&s);
+  if (s[0] == '0' &&
+      (s[1] == 'x' || s[1] == 'X')) {  /* hex? */
+    s += 2;  /* skip '0x' */
+    for (; lisxdigit(cast_uchar(*s)); s++) {
+      a = a * 16 + luaO_hexavalue(*s);
+      empty = 0;
+    }
+  }
+  else {  /* decimal */
+    for (; lisdigit(cast_uchar(*s)); s++) {
+      int d = *s - '0';
+      if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg))  /* overflow? */
+        return NULL;  /* do not accept it (as integer) */
+      a = a * 10 + d;
+      empty = 0;
+    }
+  }
+  while (lisspace(cast_uchar(*s))) s++;  /* skip trailing spaces */
+  if (empty || *s != '\0') return NULL;  /* something wrong in the numeral */
+  else {
+    *result = l_castU2S((neg) ? 0u - a : a);
+    return s;
+  }
+}
+
+
+size_t luaO_str2num (const char *s, TValue *o) {
+  lua_Integer i; lua_Number n;
+  const char *e;
+  if ((e = l_str2int(s, &i)) != NULL) {  /* try as an integer */
+    setivalue(o, i);
+  }
+  else if ((e = l_str2d(s, &n)) != NULL) {  /* else try as a float */
+    setfltvalue(o, n);
+  }
+  else
+    return 0;  /* conversion failed */
+  return (e - s) + 1;  /* success; return string size */
+}
+
+
+int luaO_utf8esc (char *buff, unsigned long x) {
+  int n = 1;  /* number of bytes put in buffer (backwards) */
+  lua_assert(x <= 0x10FFFF);
+  if (x < 0x80)  /* ascii? */
+    buff[UTF8BUFFSZ - 1] = cast(char, x);
+  else {  /* need continuation bytes */
+    unsigned int mfb = 0x3f;  /* maximum that fits in first byte */
+    do {  /* add continuation bytes */
+      buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
+      x >>= 6;  /* remove added bits */
+      mfb >>= 1;  /* now there is one less bit available in first byte */
+    } while (x > mfb);  /* still needs continuation byte? */
+    buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x);  /* add first byte */
+  }
+  return n;
+}
+
+
+/* maximum length of the conversion of a number to a string */
+#define MAXNUMBER2STR	50
+
+
+/*
+** Convert a number object to a string
+*/
+void luaO_tostring (lua_State *L, StkId obj) {
+  char buff[MAXNUMBER2STR];
+  size_t len;
+  lua_assert(ttisnumber(obj));
+  if (ttisinteger(obj))
+    len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
+  else {
+    len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
+#if !defined(LUA_COMPAT_FLOATSTRING)
+    if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
+      buff[len++] = lua_getlocaledecpoint();
+      buff[len++] = '0';  /* adds '.0' to result */
+    }
+#endif
+  }
+  setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
+}
+
+
+static void pushstr (lua_State *L, const char *str, size_t l) {
+  setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
+  luaD_inctop(L);
+}
+
+
+/*
+** this function handles only '%d', '%c', '%f', '%p', and '%s' 
+   conventional formats, plus Lua-specific '%I' and '%U'
+*/
+const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
+  int n = 0;
+  for (;;) {
+    const char *e = strchr(fmt, '%');
+    if (e == NULL) break;
+    pushstr(L, fmt, e - fmt);
+    switch (*(e+1)) {
+      case 's': {  /* zero-terminated string */
+        const char *s = va_arg(argp, char *);
+        if (s == NULL) s = "(null)";
+        pushstr(L, s, strlen(s));
+        break;
+      }
+      case 'c': {  /* an 'int' as a character */
+        char buff = cast(char, va_arg(argp, int));
+        if (lisprint(cast_uchar(buff)))
+          pushstr(L, &buff, 1);
+        else  /* non-printable character; print its code */
+          luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
+        break;
+      }
+      case 'd': {  /* an 'int' */
+        setivalue(L->top, va_arg(argp, int));
+        goto top2str;
+      }
+      case 'I': {  /* a 'lua_Integer' */
+        setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
+        goto top2str;
+      }
+      case 'f': {  /* a 'lua_Number' */
+        setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
+      top2str:  /* convert the top element to a string */
+        luaD_inctop(L);
+        luaO_tostring(L, L->top - 1);
+        break;
+      }
+      case 'p': {  /* a pointer */
+        char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
+        int l = l_sprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
+        pushstr(L, buff, l);
+        break;
+      }
+      case 'U': {  /* an 'int' as a UTF-8 sequence */
+        char buff[UTF8BUFFSZ];
+        int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
+        pushstr(L, buff + UTF8BUFFSZ - l, l);
+        break;
+      }
+      case '%': {
+        pushstr(L, "%", 1);
+        break;
+      }
+      default: {
+        luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
+                         *(e + 1));
+      }
+    }
+    n += 2;
+    fmt = e+2;
+  }
+  luaD_checkstack(L, 1);
+  pushstr(L, fmt, strlen(fmt));
+  if (n > 0) luaV_concat(L, n + 1);
+  return svalue(L->top - 1);
+}
+
+
+const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
+  const char *msg;
+  va_list argp;
+  va_start(argp, fmt);
+  msg = luaO_pushvfstring(L, fmt, argp);
+  va_end(argp);
+  return msg;
+}
+
+
+/* number of chars of a literal string without the ending \0 */
+#define LL(x)	(sizeof(x)/sizeof(char) - 1)
+
+#define RETS	"..."
+#define PRE	"[string \""
+#define POS	"\"]"
+
+#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )
+
+void luaO_chunkid (char *out, const char *source, size_t bufflen) {
+  size_t l = strlen(source);
+  if (*source == '=') {  /* 'literal' source */
+    if (l <= bufflen)  /* small enough? */
+      memcpy(out, source + 1, l * sizeof(char));
+    else {  /* truncate it */
+      addstr(out, source + 1, bufflen - 1);
+      *out = '\0';
+    }
+  }
+  else if (*source == '@') {  /* file name */
+    if (l <= bufflen)  /* small enough? */
+      memcpy(out, source + 1, l * sizeof(char));
+    else {  /* add '...' before rest of name */
+      addstr(out, RETS, LL(RETS));
+      bufflen -= LL(RETS);
+      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
+    }
+  }
+  else {  /* string; format as [string "source"] */
+    const char *nl = strchr(source, '\n');  /* find first new line (if any) */
+    addstr(out, PRE, LL(PRE));  /* add prefix */
+    bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
+    if (l < bufflen && nl == NULL) {  /* small one-line source? */
+      addstr(out, source, l);  /* keep it */
+    }
+    else {
+      if (nl != NULL) l = nl - source;  /* stop at first newline */
+      if (l > bufflen) l = bufflen;
+      addstr(out, source, l);
+      addstr(out, RETS, LL(RETS));
+    }
+    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
+  }
+}
+
diff --git a/src/lobject.h b/src/lobject.h
new file mode 100644
index 0000000..2d52b41
--- /dev/null
+++ b/src/lobject.h
@@ -0,0 +1,549 @@
+/*
+** $Id: lobject.h,v 2.116 2015/11/03 18:33:10 roberto Exp $
+** Type definitions for Lua objects
+** See Copyright Notice in lua.h
+*/
+
+
+#ifndef lobject_h
+#define lobject_h
+
+
+#include <stdarg.h>
+
+
+#include "llimits.h"
+#include "lua.h"
+
+
+/*
+** Extra tags for non-values
+*/
+#define LUA_TPROTO	LUA_NUMTAGS		/* function prototypes */
+#define LUA_TDEADKEY	(LUA_NUMTAGS+1)		/* removed keys in tables */
+
+/*
+** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
+*/
+#define LUA_TOTALTAGS	(LUA_TPROTO + 2)
+
+
+/*
+** tags for Tagged Values have the following use of bits:
+** bits 0-3: actual tag (a LUA_T* value)
+** bits 4-5: variant bits
+** bit 6: whether value is collectable
+*/
+
+
+/*
+** LUA_TFUNCTION variants:
+** 0 - Lua function
+** 1 - light C function
+** 2 - regular C function (closure)
+*/
+
+/* Variant tags for functions */
+#define LUA_TLCL	(LUA_TFUNCTION | (0 << 4))  /* Lua closure */
+#define LUA_TLCF	(LUA_TFUNCTION | (1 << 4))  /* light C function */
+#define LUA_TCCL	(LUA_TFUNCTION | (2 << 4))  /* C closure */
+
+
+/* Variant tags for strings */
+#define LUA_TSHRSTR	(LUA_TSTRING | (0 << 4))  /* short strings */
+#define LUA_TLNGSTR	(LUA_TSTRING | (1 << 4))  /* long strings */
+
+
+/* Variant tags for numbers */
+#define LUA_TNUMFLT	(LUA_TNUMBER | (0 << 4))  /* float numbers */
+#define LUA_TNUMINT	(LUA_TNUMBER | (1 << 4))  /* integer numbers */
+
+
+/* Bit mark for collectable types */
+#define BIT_ISCOLLECTABLE	(1 << 6)
+
+/* mark a tag as collectable */
+#define ctb(t)			((t) | BIT_ISCOLLECTABLE)
+
+
+/*
+** Common type for all collectable objects
+*/
+typedef struct GCObject GCObject;
+
+
+/*
+** Common Header for all collectable objects (in macro form, to be
+** included in other objects)
+*/
+#define CommonHeader	GCObject *next; lu_byte tt; lu_byte marked
+
+
+/*
+** Common type has only the common header
+*/
+struct GCObject {
+  CommonHeader;
+};
+
+
+
+
+/*
+** Tagged Values. This is the basic representation of values in Lua,
+** an actual value plus a tag with its type.
+*/
+
+/*
+** Union of all Lua values
+*/
+typedef union Value {
+  GCObject *gc;    /* collectable objects */
+  void *p;         /* light userdata */
+  int b;           /* booleans */
+  lua_CFunction f; /* light C functions */
+  lua_Integer i;   /* integer numbers */
+  lua_Number n;    /* float numbers */
+} Value;
+
+
+#define TValuefields	Value value_; int tt_
+
+
+typedef struct lua_TValue {
+  TValuefields;
+} TValue;
+
+
+
+/* macro defining a nil value */
+#define NILCONSTANT	{NULL}, LUA_TNIL
+
+
+#define val_(o)		((o)->value_)
+
+
+/* raw type tag of a TValue */
+#define rttype(o)	((o)->tt_)
+
+/* tag with no variants (bits 0-3) */
+#define novariant(x)	((x) & 0x0F)
+
+/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
+#define ttype(o)	(rttype(o) & 0x3F)
+
+/* type tag of a TValue with no variants (bits 0-3) */
+#define ttnov(o)	(novariant(rttype(o)))
+
+
+/* Macros to test type */
+#define checktag(o,t)		(rttype(o) == (t))
+#define checktype(o,t)		(ttnov(o) == (t))
+#define ttisnumber(o)		checktype((o), LUA_TNUMBER)
+#define ttisfloat(o)		checktag((o), LUA_TNUMFLT)
+#define ttisinteger(o)		checktag((o), LUA_TNUMINT)
+#define ttisnil(o)		checktag((o), LUA_TNIL)
+#define ttisboolean(o)		checktag((o), LUA_TBOOLEAN)
+#define ttislightuserdata(o)	checktag((o), LUA_TLIGHTUSERDATA)
+#define ttisstring(o)		checktype((o), LUA_TSTRING)
+#define ttisshrstring(o)	checktag((o), ctb(LUA_TSHRSTR))
+#define ttislngstring(o)	checktag((o), ctb(LUA_TLNGSTR))
+#define ttistable(o)		checktag((o), ctb(LUA_TTABLE))
+#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
+#define ttisclosure(o)		((rttype(o) & 0x1F) == LUA_TFUNCTION)
+#define ttisCclosure(o)		checktag((o), ctb(LUA_TCCL))
+#define ttisLclosure(o)		checktag((o), ctb(LUA_TLCL))
+#define ttislcf(o)		checktag((o), LUA_TLCF)
+#define ttisfulluserdata(o)	checktag((o), ctb(LUA_TUSERDATA))
+#define ttisthread(o)		checktag((o), ctb(LUA_TTHREAD))
+#define ttisdeadkey(o)		checktag((o), LUA_TDEADKEY)
+
+
+/* Macros to access values */
+#define ivalue(o)	check_exp(ttisinteger(o), val_(o).i)
+#define fltvalue(o)	check_exp(ttisfloat(o), val_(o).n)
+#define nvalue(o)	check_exp(ttisnumber(o), \
+	(ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
+#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)
+#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
+#define tsvalue(o)	check_exp(ttisstring(o), gco2ts(val_(o).gc))
+#define uvalue(o)	check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))
+#define clvalue(o)	check_exp(ttisclosure(o), gco2cl(val_(o).gc))
+#define clLvalue(o)	check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
+#define clCvalue(o)	check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))
+#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
+#define hvalue(o)	check_exp(ttistable(o), gco2t(val_(o).gc))
+#define bvalue(o)	check_exp(ttisboolean(o), val_(o).b)
+#define thvalue(o)	check_exp(ttisthread(o), gco2th(val_(o).gc))
+/* a dead value may get the 'gc' field, but cannot access its contents */
+#define deadvalue(o)	check_exp(ttisdeadkey(o), cast(void *, val_(o).gc))
+
+#define l_isfalse(o)	(ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
+
+
+#define iscollectable(o)	(rttype(o) & BIT_ISCOLLECTABLE)
+
+
+/* Macros for internal tests */
+#define righttt(obj)		(ttype(obj) == gcvalue(obj)->tt)
+
+#define checkliveness(L,obj) \
+	lua_longassert(!iscollectable(obj) || \
+		(righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj)))))
+
+
+/* Macros to set values */
+#define settt_(o,t)	((o)->tt_=(t))
+
+#define setfltvalue(obj,x) \
+  { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_TNUMFLT); }
+
+#define chgfltvalue(obj,x) \
+  { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); }
+
+#define setivalue(obj,x) \
+  { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_TNUMINT); }
+
+#define chgivalue(obj,x) \
+  { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); }
+
+#define setnilvalue(obj) settt_(obj, LUA_TNIL)
+
+#define setfvalue(obj,x) \
+  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); }
+
+#define setpvalue(obj,x) \
+  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); }
+
+#define setbvalue(obj,x) \
+  { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
+
+#define setgcovalue(L,obj,x) \
+  { TValue *io = (obj); GCObject *i_g=(x); \
+    val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); }
+
+#define setsvalue(L,obj,x) \
+  { TValue *io = (obj); TString *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
+    checkliveness(L,io); }
+
+#define setuvalue(L,obj,x) \
+  { TValue *io = (obj); Udata *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TUSERDATA)); \
+    checkliveness(L,io); }
+
+#define setthvalue(L,obj,x) \
+  { TValue *io = (obj); lua_State *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTHREAD)); \
+    checkliveness(L,io); }
+
+#define setclLvalue(L,obj,x) \
+  { TValue *io = (obj); LClosure *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TLCL)); \
+    checkliveness(L,io); }
+
+#define setclCvalue(L,obj,x) \
+  { TValue *io = (obj); CClosure *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TCCL)); \
+    checkliveness(L,io); }
+
+#define sethvalue(L,obj,x) \
+  { TValue *io = (obj); Table *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTABLE)); \
+    checkliveness(L,io); }
+
+#define setdeadvalue(obj)	settt_(obj, LUA_TDEADKEY)
+
+
+
+#define setobj(L,obj1,obj2) \
+	{ TValue *io1=(obj1); *io1 = *(obj2); \
+	  (void)L; checkliveness(L,io1); }
+
+
+/*
+** different types of assignments, according to destination
+*/
+
+/* from stack to (same) stack */
+#define setobjs2s	setobj
+/* to stack (not from same stack) */
+#define setobj2s	setobj
+#define setsvalue2s	setsvalue
+#define sethvalue2s	sethvalue
+#define setptvalue2s	setptvalue
+/* from table to same table */
+#define setobjt2t	setobj
+/* to new object */
+#define setobj2n	setobj
+#define setsvalue2n	setsvalue
+
+/* to table (define it as an expression to be used in macros) */
+#define setobj2t(L,o1,o2)  ((void)L, *(o1)=*(o2), checkliveness(L,(o1)))
+
+
+
+
+/*
+** {======================================================
+** types and prototypes
+** =======================================================
+*/
+
+
+typedef TValue *StkId;  /* index to stack elements */
+
+
+
+
+/*
+** Header for string value; string bytes follow the end of this structure
+** (aligned according to 'UTString'; see next).
+*/
+typedef struct TString {
+  CommonHeader;
+  lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
+  lu_byte shrlen;  /* length for short strings */
+  unsigned int hash;
+  union {
+    size_t lnglen;  /* length for long strings */
+    struct TString *hnext;  /* linked list for hash table */
+  } u;
+} TString;
+
+
+/*
+** Ensures that address after this type is always fully aligned.
+*/
+typedef union UTString {
+  L_Umaxalign dummy;  /* ensures maximum alignment for strings */
+  TString tsv;
+} UTString;
+
+
+/*
+** Get the actual string (array of bytes) from a 'TString'.
+** (Access to 'extra' ensures that value is really a 'TString'.)
+*/
+#define getstr(ts)  \
+  check_exp(sizeof((ts)->extra), cast(char *, (ts)) + sizeof(UTString))
+
+
+/* get the actual string (array of bytes) from a Lua value */
+#define svalue(o)       getstr(tsvalue(o))
+
+/* get string length from 'TString *s' */
+#define tsslen(s)	((s)->tt == LUA_TSHRSTR ? (s)->shrlen : (s)->u.lnglen)
+
+/* get string length from 'TValue *o' */
+#define vslen(o)	tsslen(tsvalue(o))
+
+
+/*
+** Header for userdata; memory area follows the end of this structure
+** (aligned according to 'UUdata'; see next).
+*/
+typedef struct Udata {
+  CommonHeader;
+  lu_byte ttuv_;  /* user value's tag */
+  struct Table *metatable;
+  size_t len;  /* number of bytes */
+  union Value user_;  /* user value */
+} Udata;
+
+
+/*
+** Ensures that address after this type is always fully aligned.
+*/
+typedef union UUdata {
+  L_Umaxalign dummy;  /* ensures maximum alignment for 'local' udata */
+  Udata uv;
+} UUdata;
+
+
+/*
+**  Get the address of memory block inside 'Udata'.
+** (Access to 'ttuv_' ensures that value is really a 'Udata'.)
+*/
+#define getudatamem(u)  \
+  check_exp(sizeof((u)->ttuv_), (cast(char*, (u)) + sizeof(UUdata)))
+
+#define setuservalue(L,u,o) \
+	{ const TValue *io=(o); Udata *iu = (u); \
+	  iu->user_ = io->value_; iu->ttuv_ = rttype(io); \
+	  checkliveness(L,io); }
+
+
+#define getuservalue(L,u,o) \
+	{ TValue *io=(o); const Udata *iu = (u); \
+	  io->value_ = iu->user_; settt_(io, iu->ttuv_); \
+	  checkliveness(L,io); }
+
+
+/*
+** Description of an upvalue for function prototypes
+*/
+typedef struct Upvaldesc {
+  TString *name;  /* upvalue name (for debug information) */
+  lu_byte instack;  /* whether it is in stack (register) */
+  lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
+} Upvaldesc;
+
+
+/*
+** Description of a local variable for function prototypes
+** (used for debug information)
+*/
+typedef struct LocVar {
+  TString *varname;
+  int startpc;  /* first point where variable is active */
+  int endpc;    /* first point where variable is dead */
+} LocVar;
+
+
+/*
+** Function Prototypes
+*/
+typedef struct Proto {
+  CommonHeader;
+  lu_byte numparams;  /* number of fixed parameters */
+  lu_byte is_vararg;  /* 2: declared vararg; 1: uses vararg */
+  lu_byte maxstacksize;  /* number of registers needed by this function */
+  int sizeupvalues;  /* size of 'upvalues' */
+  int sizek;  /* size of 'k' */
+  int sizecode;
+  int sizelineinfo;
+  int sizep;  /* size of 'p' */
+  int sizelocvars;
+  int linedefined;  /* debug information  */
+  int lastlinedefined;  /* debug information  */
+  TValue *k;  /* constants used by the function */
+  Instruction *code;  /* opcodes */
+  struct Proto **p;  /* functions defined inside the function */
+  int *lineinfo;  /* map from opcodes to source lines (debug information) */
+  LocVar *locvars;  /* information about local variables (debug information) */
+  Upvaldesc *upvalues;  /* upvalue information */
+  struct LClosure *cache;  /* last-created closure with this prototype */
+  TString  *source;  /* used for debug information */
+  GCObject *gclist;
+} Proto;
+
+
+
+/*
+** Lua Upvalues
+*/
+typedef struct UpVal UpVal;
+
+
+/*
+** Closures
+*/
+
+#define ClosureHeader \
+	CommonHeader; lu_byte nupvalues; GCObject *gclist
+
+typedef struct CClosure {
+  ClosureHeader;
+  lua_CFunction f;
+  TValue upvalue[1];  /* list of upvalues */
+} CClosure;
+
+
+typedef struct LClosure {
+  ClosureHeader;
+  struct Proto *p;
+  UpVal *upvals[1];  /* list of upvalues */
+} LClosure;
+
+
+typedef union Closure {
+  CClosure c;
+  LClosure l;
+} Closure;
+
+
+#define isLfunction(o)	ttisLclosure(o)
+
+#define getproto(o)	(clLvalue(o)->p)
+
+
+/*
+** Tables
+*/
+
+typedef union TKey {
+  struct {
+    TValuefields;
+    int next;  /* for chaining (offset for next node) */
+  } nk;
+  TValue tvk;
+} TKey;
+
+
+/* copy a value into a key without messing up field 'next' */
+#define setnodekey(L,key,obj) \
+	{ TKey *k_=(key); const TValue *io_=(obj); \
+	  k_->nk.value_ = io_->value_; k_->nk.tt_ = io_->tt_; \
+	  (void)L; checkliveness(L,io_); }
+
+
+typedef struct Node {
+  TValue i_val;
+  TKey i_key;
+} Node;
+
+
+typedef struct Table {
+  CommonHeader;
+  lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
+  lu_byte lsizenode;  /* log2 of size of 'node' array */
+  unsigned int sizearray;  /* size of 'array' array */
+  TValue *array;  /* array part */
+  Node *node;
+  Node *lastfree;  /* any free position is before this position */
+  struct Table *metatable;
+  GCObject *gclist;
+} Table;
+
+
+
+/*
+** 'module' operation for hashing (size is always a power of 2)
+*/
+#define lmod(s,size) \
+	(check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
+
+
+#define twoto(x)	(1<<(x))
+#define sizenode(t)	(twoto((t)->lsizenode))
+
+
+/*
+** (address of) a fixed nil value
+*/
+#define luaO_nilobject		(&luaO_nilobject_)
+
+
+LUAI_DDEC const TValue luaO_nilobject_;
+
+/* size of buffer for 'luaO_utf8esc' function */
+#define UTF8BUFFSZ	8
+
+LUAI_FUNC int luaO_int2fb (unsigned int x);
+LUAI_FUNC int luaO_fb2int (int x);
+LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x);
+LUAI_FUNC int luaO_ceillog2 (unsigned int x);
+LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1,
+                           const TValue *p2, TValue *res);
+LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o);
+LUAI_FUNC int luaO_hexavalue (int c);
+LUAI_FUNC void luaO_tostring (lua_State *L, StkId obj);
+LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
+                                                       va_list argp);
+LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
+LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
+
+
+#endif
+
diff --git a/src/lopcodes.c b/src/lopcodes.c
new file mode 100644
index 0000000..a1cbef8
--- /dev/null
+++ b/src/lopcodes.c
@@ -0,0 +1,124 @@
+/*
+** $Id: lopcodes.c,v 1.55 2015/01/05 13:48:33 roberto Exp $
+** Opcodes for Lua virtual machine
+** See Copyright Notice in lua.h
+*/
+
+#define lopcodes_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+
+#include "lopcodes.h"
+
+
+/* ORDER OP */
+
+LUAI_DDEF const char *const luaP_opnames[NUM_OPCODES+1] = {
+  "MOVE",
+  "LOADK",
+  "LOADKX",
+  "LOADBOOL",
+  "LOADNIL",
+  "GETUPVAL",
+  "GETTABUP",
+  "GETTABLE",
+  "SETTABUP",
+  "SETUPVAL",
+  "SETTABLE",
+  "NEWTABLE",
+  "SELF",
+  "ADD",
+  "SUB",
+  "MUL",
+  "MOD",
+  "POW",
+  "DIV",
+  "IDIV",
+  "BAND",
+  "BOR",
+  "BXOR",
+  "SHL",
+  "SHR",
+  "UNM",
+  "BNOT",
+  "NOT",
+  "LEN",
+  "CONCAT",
+  "JMP",
+  "EQ",
+  "LT",
+  "LE",
+  "TEST",
+  "TESTSET",
+  "CALL",
+  "TAILCALL",
+  "RETURN",
+  "FORLOOP",
+  "FORPREP",
+  "TFORCALL",
+  "TFORLOOP",
+  "SETLIST",
+  "CLOSURE",
+  "VARARG",
+  "EXTRAARG",
+  NULL
+};
+
+
+#define opmode(t,a,b,c,m) (((t)<<7) | ((a)<<6) | ((b)<<4) | ((c)<<2) | (m))
+
+LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = {
+/*       T  A    B       C     mode		   opcode	*/
+  opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_MOVE */
+ ,opmode(0, 1, OpArgK, OpArgN, iABx)		/* OP_LOADK */
+ ,opmode(0, 1, OpArgN, OpArgN, iABx)		/* OP_LOADKX */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_LOADBOOL */
+ ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_LOADNIL */
+ ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_GETUPVAL */
+ ,opmode(0, 1, OpArgU, OpArgK, iABC)		/* OP_GETTABUP */
+ ,opmode(0, 1, OpArgR, OpArgK, iABC)		/* OP_GETTABLE */
+ ,opmode(0, 0, OpArgK, OpArgK, iABC)		/* OP_SETTABUP */
+ ,opmode(0, 0, OpArgU, OpArgN, iABC)		/* OP_SETUPVAL */
+ ,opmode(0, 0, OpArgK, OpArgK, iABC)		/* OP_SETTABLE */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_NEWTABLE */
+ ,opmode(0, 1, OpArgR, OpArgK, iABC)		/* OP_SELF */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_ADD */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SUB */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_MUL */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_MOD */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_POW */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_DIV */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_IDIV */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_BAND */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_BOR */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_BXOR */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SHL */
+ ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SHR */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_UNM */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_BNOT */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_NOT */
+ ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_LEN */
+ ,opmode(0, 1, OpArgR, OpArgR, iABC)		/* OP_CONCAT */
+ ,opmode(0, 0, OpArgR, OpArgN, iAsBx)		/* OP_JMP */
+ ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_EQ */
+ ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_LT */
+ ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_LE */
+ ,opmode(1, 0, OpArgN, OpArgU, iABC)		/* OP_TEST */
+ ,opmode(1, 1, OpArgR, OpArgU, iABC)		/* OP_TESTSET */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_CALL */
+ ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_TAILCALL */
+ ,opmode(0, 0, OpArgU, OpArgN, iABC)		/* OP_RETURN */
+ ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_FORLOOP */
+ ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_FORPREP */
+ ,opmode(0, 0, OpArgN, OpArgU, iABC)		/* OP_TFORCALL */
+ ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_TFORLOOP */
+ ,opmode(0, 0, OpArgU, OpArgU, iABC)		/* OP_SETLIST */
+ ,opmode(0, 1, OpArgU, OpArgN, iABx)		/* OP_CLOSURE */
+ ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_VARARG */
+ ,opmode(0, 0, OpArgU, OpArgU, iAx)		/* OP_EXTRAARG */
+};
+
diff --git a/src/lopcodes.h b/src/lopcodes.h
new file mode 100644
index 0000000..864b8e4
--- /dev/null
+++ b/src/lopcodes.h
@@ -0,0 +1,295 @@
+/*
+** $Id: lopcodes.h,v 1.148 2014/10/25 11:50:46 roberto Exp $
+** Opcodes for Lua virtual machine
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lopcodes_h
+#define lopcodes_h
+
+#include "llimits.h"
+
+
+/*===========================================================================
+  We assume that instructions are unsigned numbers.
+  All instructions have an opcode in the first 6 bits.
+  Instructions can have the following fields:
+	'A' : 8 bits
+	'B' : 9 bits
+	'C' : 9 bits
+	'Ax' : 26 bits ('A', 'B', and 'C' together)
+	'Bx' : 18 bits ('B' and 'C' together)
+	'sBx' : signed Bx
+
+  A signed argument is represented in excess K; that is, the number
+  value is the unsigned value minus K. K is exactly the maximum value
+  for that argument (so that -max is represented by 0, and +max is
+  represented by 2*max), which is half the maximum for the corresponding
+  unsigned argument.
+===========================================================================*/
+
+
+enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
+
+
+/*
+** size and position of opcode arguments.
+*/
+#define SIZE_C		9
+#define SIZE_B		9
+#define SIZE_Bx		(SIZE_C + SIZE_B)
+#define SIZE_A		8
+#define SIZE_Ax		(SIZE_C + SIZE_B + SIZE_A)
+
+#define SIZE_OP		6
+
+#define POS_OP		0
+#define POS_A		(POS_OP + SIZE_OP)
+#define POS_C		(POS_A + SIZE_A)
+#define POS_B		(POS_C + SIZE_C)
+#define POS_Bx		POS_C
+#define POS_Ax		POS_A
+
+
+/*
+** limits for opcode arguments.
+** we use (signed) int to manipulate most arguments,
+** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)
+*/
+#if SIZE_Bx < LUAI_BITSINT-1
+#define MAXARG_Bx        ((1<<SIZE_Bx)-1)
+#define MAXARG_sBx        (MAXARG_Bx>>1)         /* 'sBx' is signed */
+#else
+#define MAXARG_Bx        MAX_INT
+#define MAXARG_sBx        MAX_INT
+#endif
+
+#if SIZE_Ax < LUAI_BITSINT-1
+#define MAXARG_Ax	((1<<SIZE_Ax)-1)
+#else
+#define MAXARG_Ax	MAX_INT
+#endif
+
+
+#define MAXARG_A        ((1<<SIZE_A)-1)
+#define MAXARG_B        ((1<<SIZE_B)-1)
+#define MAXARG_C        ((1<<SIZE_C)-1)
+
+
+/* creates a mask with 'n' 1 bits at position 'p' */
+#define MASK1(n,p)	((~((~(Instruction)0)<<(n)))<<(p))
+
+/* creates a mask with 'n' 0 bits at position 'p' */
+#define MASK0(n,p)	(~MASK1(n,p))
+
+/*
+** the following macros help to manipulate instructions
+*/
+
+#define GET_OPCODE(i)	(cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0)))
+#define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
+		((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
+
+#define getarg(i,pos,size)	(cast(int, ((i)>>pos) & MASK1(size,0)))
+#define setarg(i,v,pos,size)	((i) = (((i)&MASK0(size,pos)) | \
+                ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
+
+#define GETARG_A(i)	getarg(i, POS_A, SIZE_A)
+#define SETARG_A(i,v)	setarg(i, v, POS_A, SIZE_A)
+
+#define GETARG_B(i)	getarg(i, POS_B, SIZE_B)
+#define SETARG_B(i,v)	setarg(i, v, POS_B, SIZE_B)
+
+#define GETARG_C(i)	getarg(i, POS_C, SIZE_C)
+#define SETARG_C(i,v)	setarg(i, v, POS_C, SIZE_C)
+
+#define GETARG_Bx(i)	getarg(i, POS_Bx, SIZE_Bx)
+#define SETARG_Bx(i,v)	setarg(i, v, POS_Bx, SIZE_Bx)
+
+#define GETARG_Ax(i)	getarg(i, POS_Ax, SIZE_Ax)
+#define SETARG_Ax(i,v)	setarg(i, v, POS_Ax, SIZE_Ax)
+
+#define GETARG_sBx(i)	(GETARG_Bx(i)-MAXARG_sBx)
+#define SETARG_sBx(i,b)	SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
+
+
+#define CREATE_ABC(o,a,b,c)	((cast(Instruction, o)<<POS_OP) \
+			| (cast(Instruction, a)<<POS_A) \
+			| (cast(Instruction, b)<<POS_B) \
+			| (cast(Instruction, c)<<POS_C))
+
+#define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \
+			| (cast(Instruction, a)<<POS_A) \
+			| (cast(Instruction, bc)<<POS_Bx))
+
+#define CREATE_Ax(o,a)		((cast(Instruction, o)<<POS_OP) \
+			| (cast(Instruction, a)<<POS_Ax))
+
+
+/*
+** Macros to operate RK indices
+*/
+
+/* this bit 1 means constant (0 means register) */
+#define BITRK		(1 << (SIZE_B - 1))
+
+/* test whether value is a constant */
+#define ISK(x)		((x) & BITRK)
+
+/* gets the index of the constant */
+#define INDEXK(r)	((int)(r) & ~BITRK)
+
+#define MAXINDEXRK	(BITRK - 1)
+
+/* code a constant index as a RK value */
+#define RKASK(x)	((x) | BITRK)
+
+
+/*
+** invalid register that fits in 8 bits
+*/
+#define NO_REG		MAXARG_A
+
+
+/*
+** R(x) - register
+** Kst(x) - constant (in constant table)
+** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
+*/
+
+
+/*
+** grep "ORDER OP" if you change these enums
+*/
+
+typedef enum {
+/*----------------------------------------------------------------------
+name		args	description
+------------------------------------------------------------------------*/
+OP_MOVE,/*	A B	R(A) := R(B)					*/
+OP_LOADK,/*	A Bx	R(A) := Kst(Bx)					*/
+OP_LOADKX,/*	A 	R(A) := Kst(extra arg)				*/
+OP_LOADBOOL,/*	A B C	R(A) := (Bool)B; if (C) pc++			*/
+OP_LOADNIL,/*	A B	R(A), R(A+1), ..., R(A+B) := nil		*/
+OP_GETUPVAL,/*	A B	R(A) := UpValue[B]				*/
+
+OP_GETTABUP,/*	A B C	R(A) := UpValue[B][RK(C)]			*/
+OP_GETTABLE,/*	A B C	R(A) := R(B)[RK(C)]				*/
+
+OP_SETTABUP,/*	A B C	UpValue[A][RK(B)] := RK(C)			*/
+OP_SETUPVAL,/*	A B	UpValue[B] := R(A)				*/
+OP_SETTABLE,/*	A B C	R(A)[RK(B)] := RK(C)				*/
+
+OP_NEWTABLE,/*	A B C	R(A) := {} (size = B,C)				*/
+
+OP_SELF,/*	A B C	R(A+1) := R(B); R(A) := R(B)[RK(C)]		*/
+
+OP_ADD,/*	A B C	R(A) := RK(B) + RK(C)				*/
+OP_SUB,/*	A B C	R(A) := RK(B) - RK(C)				*/
+OP_MUL,/*	A B C	R(A) := RK(B) * RK(C)				*/
+OP_MOD,/*	A B C	R(A) := RK(B) % RK(C)				*/
+OP_POW,/*	A B C	R(A) := RK(B) ^ RK(C)				*/
+OP_DIV,/*	A B C	R(A) := RK(B) / RK(C)				*/
+OP_IDIV,/*	A B C	R(A) := RK(B) // RK(C)				*/
+OP_BAND,/*	A B C	R(A) := RK(B) & RK(C)				*/
+OP_BOR,/*	A B C	R(A) := RK(B) | RK(C)				*/
+OP_BXOR,/*	A B C	R(A) := RK(B) ~ RK(C)				*/
+OP_SHL,/*	A B C	R(A) := RK(B) << RK(C)				*/
+OP_SHR,/*	A B C	R(A) := RK(B) >> RK(C)				*/
+OP_UNM,/*	A B	R(A) := -R(B)					*/
+OP_BNOT,/*	A B	R(A) := ~R(B)					*/
+OP_NOT,/*	A B	R(A) := not R(B)				*/
+OP_LEN,/*	A B	R(A) := length of R(B)				*/
+
+OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
+
+OP_JMP,/*	A sBx	pc+=sBx; if (A) close all upvalues >= R(A - 1)	*/
+OP_EQ,/*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
+OP_LT,/*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++		*/
+OP_LE,/*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++		*/
+
+OP_TEST,/*	A C	if not (R(A) <=> C) then pc++			*/
+OP_TESTSET,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/
+
+OP_CALL,/*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
+OP_TAILCALL,/*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
+OP_RETURN,/*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
+
+OP_FORLOOP,/*	A sBx	R(A)+=R(A+2);
+			if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
+OP_FORPREP,/*	A sBx	R(A)-=R(A+2); pc+=sBx				*/
+
+OP_TFORCALL,/*	A C	R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));	*/
+OP_TFORLOOP,/*	A sBx	if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
+
+OP_SETLIST,/*	A B C	R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B	*/
+
+OP_CLOSURE,/*	A Bx	R(A) := closure(KPROTO[Bx])			*/
+
+OP_VARARG,/*	A B	R(A), R(A+1), ..., R(A+B-2) = vararg		*/
+
+OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
+} OpCode;
+
+
+#define NUM_OPCODES	(cast(int, OP_EXTRAARG) + 1)
+
+
+
+/*===========================================================================
+  Notes:
+  (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then 'top' is
+  set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
+  OP_SETLIST) may use 'top'.
+
+  (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
+  set top (like in OP_CALL with C == 0).
+
+  (*) In OP_RETURN, if (B == 0) then return up to 'top'.
+
+  (*) In OP_SETLIST, if (B == 0) then B = 'top'; if (C == 0) then next
+  'instruction' is EXTRAARG(real C).
+
+  (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
+
+  (*) For comparisons, A specifies what condition the test should accept
+  (true or false).
+
+  (*) All 'skips' (pc++) assume that next instruction is a jump.
+
+===========================================================================*/
+
+
+/*
+** masks for instruction properties. The format is:
+** bits 0-1: op mode
+** bits 2-3: C arg mode
+** bits 4-5: B arg mode
+** bit 6: instruction set register A
+** bit 7: operator is a test (next instruction must be a jump)
+*/
+
+enum OpArgMask {
+  OpArgN,  /* argument is not used */
+  OpArgU,  /* argument is used */
+  OpArgR,  /* argument is a register or a jump offset */
+  OpArgK   /* argument is a constant or register/constant */
+};
+
+LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
+
+#define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 3))
+#define getBMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
+#define getCMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
+#define testAMode(m)	(luaP_opmodes[m] & (1 << 6))
+#define testTMode(m)	(luaP_opmodes[m] & (1 << 7))
+
+
+LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
+
+
+/* number of list items to accumulate before a SETLIST instruction */
+#define LFIELDS_PER_FLUSH	50
+
+
+#endif
diff --git a/src/loslib.c b/src/loslib.c
new file mode 100644
index 0000000..4810655
--- /dev/null
+++ b/src/loslib.c
@@ -0,0 +1,403 @@
+/*
+** $Id: loslib.c,v 1.64 2016/04/18 13:06:55 roberto Exp $
+** Standard Operating System library
+** See Copyright Notice in lua.h
+*/
+
+#define loslib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <errno.h>
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** {==================================================================
+** List of valid conversion specifiers for the 'strftime' function;
+** options are grouped by length; group of length 2 start with '||'.
+** ===================================================================
+*/
+#if !defined(LUA_STRFTIMEOPTIONS)	/* { */
+
+/* options for ANSI C 89 */
+#define L_STRFTIMEC89		"aAbBcdHIjmMpSUwWxXyYZ%"
+
+/* options for ISO C 99 and POSIX */
+#define L_STRFTIMEC99 "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%" \
+	"||" "EcECExEXEyEY" "OdOeOHOIOmOMOSOuOUOVOwOWOy"
+
+/* options for Windows */
+#define L_STRFTIMEWIN "aAbBcdHIjmMpSUwWxXyYzZ%" \
+	"||" "#c#x#d#H#I#j#m#M#S#U#w#W#y#Y"
+
+#if defined(LUA_USE_WINDOWS)
+#define LUA_STRFTIMEOPTIONS	L_STRFTIMEWIN
+#elif defined(LUA_USE_C89)
+#define LUA_STRFTIMEOPTIONS	L_STRFTIMEC89
+#else  /* C99 specification */
+#define LUA_STRFTIMEOPTIONS	L_STRFTIMEC99
+#endif
+
+#endif					/* } */
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Configuration for time-related stuff
+** ===================================================================
+*/
+
+#if !defined(l_time_t)		/* { */
+/*
+** type to represent time_t in Lua
+*/
+#define l_timet			lua_Integer
+#define l_pushtime(L,t)		lua_pushinteger(L,(lua_Integer)(t))
+
+static time_t l_checktime (lua_State *L, int arg) {
+  lua_Integer t = luaL_checkinteger(L, arg);
+  luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
+  return (time_t)t;
+}
+
+#endif				/* } */
+
+
+#if !defined(l_gmtime)		/* { */
+/*
+** By default, Lua uses gmtime/localtime, except when POSIX is available,
+** where it uses gmtime_r/localtime_r
+*/
+
+#if defined(LUA_USE_POSIX)	/* { */
+
+#define l_gmtime(t,r)		gmtime_r(t,r)
+#define l_localtime(t,r)	localtime_r(t,r)
+
+#else				/* }{ */
+
+/* ISO C definitions */
+#define l_gmtime(t,r)		((void)(r)->tm_sec, gmtime(t))
+#define l_localtime(t,r)  	((void)(r)->tm_sec, localtime(t))
+
+#endif				/* } */
+
+#endif				/* } */
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Configuration for 'tmpnam':
+** By default, Lua uses tmpnam except when POSIX is available, where
+** it uses mkstemp.
+** ===================================================================
+*/
+#if !defined(lua_tmpnam)	/* { */
+
+#if defined(LUA_USE_POSIX)	/* { */
+
+#include <unistd.h>
+
+#define LUA_TMPNAMBUFSIZE	32
+
+#if !defined(LUA_TMPNAMTEMPLATE)
+#define LUA_TMPNAMTEMPLATE	"/tmp/lua_XXXXXX"
+#endif
+
+#define lua_tmpnam(b,e) { \
+        strcpy(b, LUA_TMPNAMTEMPLATE); \
+        e = mkstemp(b); \
+        if (e != -1) close(e); \
+        e = (e == -1); }
+
+#else				/* }{ */
+
+/* ISO C definitions */
+#define LUA_TMPNAMBUFSIZE	L_tmpnam
+#define lua_tmpnam(b,e)		{ e = (tmpnam(b) == NULL); }
+
+#endif				/* } */
+
+#endif				/* } */
+/* }================================================================== */
+
+
+
+
+static int os_execute (lua_State *L) {
+  const char *cmd = luaL_optstring(L, 1, NULL);
+  int stat = system(cmd);
+  if (cmd != NULL)
+    return luaL_execresult(L, stat);
+  else {
+    lua_pushboolean(L, stat);  /* true if there is a shell */
+    return 1;
+  }
+}
+
+
+static int os_remove (lua_State *L) {
+  const char *filename = luaL_checkstring(L, 1);
+  return luaL_fileresult(L, remove(filename) == 0, filename);
+}
+
+
+static int os_rename (lua_State *L) {
+  const char *fromname = luaL_checkstring(L, 1);
+  const char *toname = luaL_checkstring(L, 2);
+  return luaL_fileresult(L, rename(fromname, toname) == 0, NULL);
+}
+
+
+static int os_tmpname (lua_State *L) {
+  char buff[LUA_TMPNAMBUFSIZE];
+  int err;
+  lua_tmpnam(buff, err);
+  if (err)
+    return luaL_error(L, "unable to generate a unique filename");
+  lua_pushstring(L, buff);
+  return 1;
+}
+
+
+static int os_getenv (lua_State *L) {
+  lua_pushstring(L, getenv(luaL_checkstring(L, 1)));  /* if NULL push nil */
+  return 1;
+}
+
+
+static int os_clock (lua_State *L) {
+  lua_pushnumber(L, ((lua_Number)clock())/(lua_Number)CLOCKS_PER_SEC);
+  return 1;
+}
+
+
+/*
+** {======================================================
+** Time/Date operations
+** { year=%Y, month=%m, day=%d, hour=%H, min=%M, sec=%S,
+**   wday=%w+1, yday=%j, isdst=? }
+** =======================================================
+*/
+
+static void setfield (lua_State *L, const char *key, int value) {
+  lua_pushinteger(L, value);
+  lua_setfield(L, -2, key);
+}
+
+static void setboolfield (lua_State *L, const char *key, int value) {
+  if (value < 0)  /* undefined? */
+    return;  /* does not set field */
+  lua_pushboolean(L, value);
+  lua_setfield(L, -2, key);
+}
+
+
+/*
+** Set all fields from structure 'tm' in the table on top of the stack
+*/
+static void setallfields (lua_State *L, struct tm *stm) {
+  setfield(L, "sec", stm->tm_sec);
+  setfield(L, "min", stm->tm_min);
+  setfield(L, "hour", stm->tm_hour);
+  setfield(L, "day", stm->tm_mday);
+  setfield(L, "month", stm->tm_mon + 1);
+  setfield(L, "year", stm->tm_year + 1900);
+  setfield(L, "wday", stm->tm_wday + 1);
+  setfield(L, "yday", stm->tm_yday + 1);
+  setboolfield(L, "isdst", stm->tm_isdst);
+}
+
+
+static int getboolfield (lua_State *L, const char *key) {
+  int res;
+  res = (lua_getfield(L, -1, key) == LUA_TNIL) ? -1 : lua_toboolean(L, -1);
+  lua_pop(L, 1);
+  return res;
+}
+
+
+/* maximum value for date fields (to avoid arithmetic overflows with 'int') */
+#if !defined(L_MAXDATEFIELD)
+#define L_MAXDATEFIELD	(INT_MAX / 2)
+#endif
+
+static int getfield (lua_State *L, const char *key, int d, int delta) {
+  int isnum;
+  int t = lua_getfield(L, -1, key);  /* get field and its type */
+  lua_Integer res = lua_tointegerx(L, -1, &isnum);
+  if (!isnum) {  /* field is not an integer? */
+    if (t != LUA_TNIL)  /* some other value? */
+      return luaL_error(L, "field '%s' is not an integer", key);
+    else if (d < 0)  /* absent field; no default? */
+      return luaL_error(L, "field '%s' missing in date table", key);
+    res = d;
+  }
+  else {
+    if (!(-L_MAXDATEFIELD <= res && res <= L_MAXDATEFIELD))
+      return luaL_error(L, "field '%s' is out-of-bound", key);
+    res -= delta;
+  }
+  lua_pop(L, 1);
+  return (int)res;
+}
+
+
+static const char *checkoption (lua_State *L, const char *conv, char *buff) {
+  const char *option;
+  int oplen = 1;
+  for (option = LUA_STRFTIMEOPTIONS; *option != '\0'; option += oplen) {
+    if (*option == '|')  /* next block? */
+      oplen++;  /* next length */
+    else if (memcmp(conv, option, oplen) == 0) {  /* match? */
+      memcpy(buff, conv, oplen);  /* copy valid option to buffer */
+      buff[oplen] = '\0';
+      return conv + oplen;  /* return next item */
+    }
+  }
+  luaL_argerror(L, 1,
+    lua_pushfstring(L, "invalid conversion specifier '%%%s'", conv));
+  return conv;  /* to avoid warnings */
+}
+
+
+/* maximum size for an individual 'strftime' item */
+#define SIZETIMEFMT	250
+
+
+static int os_date (lua_State *L) {
+  const char *s = luaL_optstring(L, 1, "%c");
+  time_t t = luaL_opt(L, l_checktime, 2, time(NULL));
+  struct tm tmr, *stm;
+  if (*s == '!') {  /* UTC? */
+    stm = l_gmtime(&t, &tmr);
+    s++;  /* skip '!' */
+  }
+  else
+    stm = l_localtime(&t, &tmr);
+  if (stm == NULL)  /* invalid date? */
+    luaL_error(L, "time result cannot be represented in this installation");
+  if (strcmp(s, "*t") == 0) {
+    lua_createtable(L, 0, 9);  /* 9 = number of fields */
+    setallfields(L, stm);
+  }
+  else {
+    char cc[4];  /* buffer for individual conversion specifiers */
+    luaL_Buffer b;
+    cc[0] = '%';
+    luaL_buffinit(L, &b);
+    while (*s) {
+      if (*s != '%')  /* not a conversion specifier? */
+        luaL_addchar(&b, *s++);
+      else {
+        size_t reslen;
+        char *buff = luaL_prepbuffsize(&b, SIZETIMEFMT);
+        s = checkoption(L, s + 1, cc + 1);  /* copy specifier to 'cc' */
+        reslen = strftime(buff, SIZETIMEFMT, cc, stm);
+        luaL_addsize(&b, reslen);
+      }
+    }
+    luaL_pushresult(&b);
+  }
+  return 1;
+}
+
+
+static int os_time (lua_State *L) {
+  time_t t;
+  if (lua_isnoneornil(L, 1))  /* called without args? */
+    t = time(NULL);  /* get current time */
+  else {
+    struct tm ts;
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_settop(L, 1);  /* make sure table is at the top */
+    ts.tm_sec = getfield(L, "sec", 0, 0);
+    ts.tm_min = getfield(L, "min", 0, 0);
+    ts.tm_hour = getfield(L, "hour", 12, 0);
+    ts.tm_mday = getfield(L, "day", -1, 0);
+    ts.tm_mon = getfield(L, "month", -1, 1);
+    ts.tm_year = getfield(L, "year", -1, 1900);
+    ts.tm_isdst = getboolfield(L, "isdst");
+    t = mktime(&ts);
+    setallfields(L, &ts);  /* update fields with normalized values */
+  }
+  if (t != (time_t)(l_timet)t || t == (time_t)(-1))
+    luaL_error(L, "time result cannot be represented in this installation");
+  l_pushtime(L, t);
+  return 1;
+}
+
+
+static int os_difftime (lua_State *L) {
+  time_t t1 = l_checktime(L, 1);
+  time_t t2 = l_checktime(L, 2);
+  lua_pushnumber(L, (lua_Number)difftime(t1, t2));
+  return 1;
+}
+
+/* }====================================================== */
+
+
+static int os_setlocale (lua_State *L) {
+  static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY,
+                      LC_NUMERIC, LC_TIME};
+  static const char *const catnames[] = {"all", "collate", "ctype", "monetary",
+     "numeric", "time", NULL};
+  const char *l = luaL_optstring(L, 1, NULL);
+  int op = luaL_checkoption(L, 2, "all", catnames);
+  lua_pushstring(L, setlocale(cat[op], l));
+  return 1;
+}
+
+
+static int os_exit (lua_State *L) {
+  int status;
+  if (lua_isboolean(L, 1))
+    status = (lua_toboolean(L, 1) ? EXIT_SUCCESS : EXIT_FAILURE);
+  else
+    status = (int)luaL_optinteger(L, 1, EXIT_SUCCESS);
+  if (lua_toboolean(L, 2))
+    lua_close(L);
+  if (L) exit(status);  /* 'if' to avoid warnings for unreachable 'return' */
+  return 0;
+}
+
+
+static const luaL_Reg syslib[] = {
+  {"clock",     os_clock},
+  {"date",      os_date},
+  {"difftime",  os_difftime},
+  {"execute",   os_execute},
+  {"exit",      os_exit},
+  {"getenv",    os_getenv},
+  {"remove",    os_remove},
+  {"rename",    os_rename},
+  {"setlocale", os_setlocale},
+  {"time",      os_time},
+  {"tmpname",   os_tmpname},
+  {NULL, NULL}
+};
+
+/* }====================================================== */
+
+
+
+LUAMOD_API int luaopen_os (lua_State *L) {
+  luaL_newlib(L, syslib);
+  return 1;
+}
+
diff --git a/src/lparser.c b/src/lparser.c
new file mode 100644
index 0000000..22530a5
--- /dev/null
+++ b/src/lparser.c
@@ -0,0 +1,1652 @@
+/*
+** $Id: lparser.c,v 2.153 2016/05/13 19:10:16 roberto Exp $
+** Lua Parser
+** See Copyright Notice in lua.h
+*/
+
+#define lparser_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "lcode.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "llex.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lparser.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+
+
+
+/* maximum number of local variables per function (must be smaller
+   than 250, due to the bytecode format) */
+#define MAXVARS		200
+
+
+#define hasmultret(k)		((k) == VCALL || (k) == VVARARG)
+
+
+/* because all strings are unified by the scanner, the parser
+   can use pointer equality for string equality */
+#define eqstr(a,b)	((a) == (b))
+
+
+/*
+** nodes for block list (list of active blocks)
+*/
+typedef struct BlockCnt {
+  struct BlockCnt *previous;  /* chain */
+  int firstlabel;  /* index of first label in this block */
+  int firstgoto;  /* index of first pending goto in this block */
+  lu_byte nactvar;  /* # active locals outside the block */
+  lu_byte upval;  /* true if some variable in the block is an upvalue */
+  lu_byte isloop;  /* true if 'block' is a loop */
+} BlockCnt;
+
+
+
+/*
+** prototypes for recursive non-terminal functions
+*/
+static void statement (LexState *ls);
+static void expr (LexState *ls, expdesc *v);
+
+
+/* semantic error */
+static l_noret semerror (LexState *ls, const char *msg) {
+  ls->t.token = 0;  /* remove "near <token>" from final message */
+  luaX_syntaxerror(ls, msg);
+}
+
+
+static l_noret error_expected (LexState *ls, int token) {
+  luaX_syntaxerror(ls,
+      luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token)));
+}
+
+
+static l_noret errorlimit (FuncState *fs, int limit, const char *what) {
+  lua_State *L = fs->ls->L;
+  const char *msg;
+  int line = fs->f->linedefined;
+  const char *where = (line == 0)
+                      ? "main function"
+                      : luaO_pushfstring(L, "function at line %d", line);
+  msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s",
+                             what, limit, where);
+  luaX_syntaxerror(fs->ls, msg);
+}
+
+
+static void checklimit (FuncState *fs, int v, int l, const char *what) {
+  if (v > l) errorlimit(fs, l, what);
+}
+
+
+static int testnext (LexState *ls, int c) {
+  if (ls->t.token == c) {
+    luaX_next(ls);
+    return 1;
+  }
+  else return 0;
+}
+
+
+static void check (LexState *ls, int c) {
+  if (ls->t.token != c)
+    error_expected(ls, c);
+}
+
+
+static void checknext (LexState *ls, int c) {
+  check(ls, c);
+  luaX_next(ls);
+}
+
+
+#define check_condition(ls,c,msg)	{ if (!(c)) luaX_syntaxerror(ls, msg); }
+
+
+
+static void check_match (LexState *ls, int what, int who, int where) {
+  if (!testnext(ls, what)) {
+    if (where == ls->linenumber)
+      error_expected(ls, what);
+    else {
+      luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
+             "%s expected (to close %s at line %d)",
+              luaX_token2str(ls, what), luaX_token2str(ls, who), where));
+    }
+  }
+}
+
+
+static TString *str_checkname (LexState *ls) {
+  TString *ts;
+  check(ls, TK_NAME);
+  ts = ls->t.seminfo.ts;
+  luaX_next(ls);
+  return ts;
+}
+
+
+static void init_exp (expdesc *e, expkind k, int i) {
+  e->f = e->t = NO_JUMP;
+  e->k = k;
+  e->u.info = i;
+}
+
+
+static void codestring (LexState *ls, expdesc *e, TString *s) {
+  init_exp(e, VK, luaK_stringK(ls->fs, s));
+}
+
+
+static void checkname (LexState *ls, expdesc *e) {
+  codestring(ls, e, str_checkname(ls));
+}
+
+
+static int registerlocalvar (LexState *ls, TString *varname) {
+  FuncState *fs = ls->fs;
+  Proto *f = fs->f;
+  int oldsize = f->sizelocvars;
+  luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
+                  LocVar, SHRT_MAX, "local variables");
+  while (oldsize < f->sizelocvars)
+    f->locvars[oldsize++].varname = NULL;
+  f->locvars[fs->nlocvars].varname = varname;
+  luaC_objbarrier(ls->L, f, varname);
+  return fs->nlocvars++;
+}
+
+
+static void new_localvar (LexState *ls, TString *name) {
+  FuncState *fs = ls->fs;
+  Dyndata *dyd = ls->dyd;
+  int reg = registerlocalvar(ls, name);
+  checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal,
+                  MAXVARS, "local variables");
+  luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1,
+                  dyd->actvar.size, Vardesc, MAX_INT, "local variables");
+  dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg);
+}
+
+
+static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) {
+  new_localvar(ls, luaX_newstring(ls, name, sz));
+}
+
+#define new_localvarliteral(ls,v) \
+	new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1)
+
+
+static LocVar *getlocvar (FuncState *fs, int i) {
+  int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx;
+  lua_assert(idx < fs->nlocvars);
+  return &fs->f->locvars[idx];
+}
+
+
+static void adjustlocalvars (LexState *ls, int nvars) {
+  FuncState *fs = ls->fs;
+  fs->nactvar = cast_byte(fs->nactvar + nvars);
+  for (; nvars; nvars--) {
+    getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc;
+  }
+}
+
+
+static void removevars (FuncState *fs, int tolevel) {
+  fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel);
+  while (fs->nactvar > tolevel)
+    getlocvar(fs, --fs->nactvar)->endpc = fs->pc;
+}
+
+
+static int searchupvalue (FuncState *fs, TString *name) {
+  int i;
+  Upvaldesc *up = fs->f->upvalues;
+  for (i = 0; i < fs->nups; i++) {
+    if (eqstr(up[i].name, name)) return i;
+  }
+  return -1;  /* not found */
+}
+
+
+static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
+  Proto *f = fs->f;
+  int oldsize = f->sizeupvalues;
+  checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues");
+  luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues,
+                  Upvaldesc, MAXUPVAL, "upvalues");
+  while (oldsize < f->sizeupvalues)
+    f->upvalues[oldsize++].name = NULL;
+  f->upvalues[fs->nups].instack = (v->k == VLOCAL);
+  f->upvalues[fs->nups].idx = cast_byte(v->u.info);
+  f->upvalues[fs->nups].name = name;
+  luaC_objbarrier(fs->ls->L, f, name);
+  return fs->nups++;
+}
+
+
+static int searchvar (FuncState *fs, TString *n) {
+  int i;
+  for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) {
+    if (eqstr(n, getlocvar(fs, i)->varname))
+      return i;
+  }
+  return -1;  /* not found */
+}
+
+
+/*
+  Mark block where variable at given level was defined
+  (to emit close instructions later).
+*/
+static void markupval (FuncState *fs, int level) {
+  BlockCnt *bl = fs->bl;
+  while (bl->nactvar > level)
+    bl = bl->previous;
+  bl->upval = 1;
+}
+
+
+/*
+  Find variable with given name 'n'. If it is an upvalue, add this
+  upvalue into all intermediate functions.
+*/
+static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
+  if (fs == NULL)  /* no more levels? */
+    init_exp(var, VVOID, 0);  /* default is global */
+  else {
+    int v = searchvar(fs, n);  /* look up locals at current level */
+    if (v >= 0) {  /* found? */
+      init_exp(var, VLOCAL, v);  /* variable is local */
+      if (!base)
+        markupval(fs, v);  /* local will be used as an upval */
+    }
+    else {  /* not found as local at current level; try upvalues */
+      int idx = searchupvalue(fs, n);  /* try existing upvalues */
+      if (idx < 0) {  /* not found? */
+        singlevaraux(fs->prev, n, var, 0);  /* try upper levels */
+        if (var->k == VVOID)  /* not found? */
+          return;  /* it is a global */
+        /* else was LOCAL or UPVAL */
+        idx  = newupvalue(fs, n, var);  /* will be a new upvalue */
+      }
+      init_exp(var, VUPVAL, idx);  /* new or old upvalue */
+    }
+  }
+}
+
+
+static void singlevar (LexState *ls, expdesc *var) {
+  TString *varname = str_checkname(ls);
+  FuncState *fs = ls->fs;
+  singlevaraux(fs, varname, var, 1);
+  if (var->k == VVOID) {  /* global name? */
+    expdesc key;
+    singlevaraux(fs, ls->envn, var, 1);  /* get environment variable */
+    lua_assert(var->k != VVOID);  /* this one must exist */
+    codestring(ls, &key, varname);  /* key is variable name */
+    luaK_indexed(fs, var, &key);  /* env[varname] */
+  }
+}
+
+
+static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
+  FuncState *fs = ls->fs;
+  int extra = nvars - nexps;
+  if (hasmultret(e->k)) {
+    extra++;  /* includes call itself */
+    if (extra < 0) extra = 0;
+    luaK_setreturns(fs, e, extra);  /* last exp. provides the difference */
+    if (extra > 1) luaK_reserveregs(fs, extra-1);
+  }
+  else {
+    if (e->k != VVOID) luaK_exp2nextreg(fs, e);  /* close last expression */
+    if (extra > 0) {
+      int reg = fs->freereg;
+      luaK_reserveregs(fs, extra);
+      luaK_nil(fs, reg, extra);
+    }
+  }
+}
+
+
+static void enterlevel (LexState *ls) {
+  lua_State *L = ls->L;
+  ++L->nCcalls;
+  checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels");
+}
+
+
+#define leavelevel(ls)	((ls)->L->nCcalls--)
+
+
+static void closegoto (LexState *ls, int g, Labeldesc *label) {
+  int i;
+  FuncState *fs = ls->fs;
+  Labellist *gl = &ls->dyd->gt;
+  Labeldesc *gt = &gl->arr[g];
+  lua_assert(eqstr(gt->name, label->name));
+  if (gt->nactvar < label->nactvar) {
+    TString *vname = getlocvar(fs, gt->nactvar)->varname;
+    const char *msg = luaO_pushfstring(ls->L,
+      "<goto %s> at line %d jumps into the scope of local '%s'",
+      getstr(gt->name), gt->line, getstr(vname));
+    semerror(ls, msg);
+  }
+  luaK_patchlist(fs, gt->pc, label->pc);
+  /* remove goto from pending list */
+  for (i = g; i < gl->n - 1; i++)
+    gl->arr[i] = gl->arr[i + 1];
+  gl->n--;
+}
+
+
+/*
+** try to close a goto with existing labels; this solves backward jumps
+*/
+static int findlabel (LexState *ls, int g) {
+  int i;
+  BlockCnt *bl = ls->fs->bl;
+  Dyndata *dyd = ls->dyd;
+  Labeldesc *gt = &dyd->gt.arr[g];
+  /* check labels in current block for a match */
+  for (i = bl->firstlabel; i < dyd->label.n; i++) {
+    Labeldesc *lb = &dyd->label.arr[i];
+    if (eqstr(lb->name, gt->name)) {  /* correct label? */
+      if (gt->nactvar > lb->nactvar &&
+          (bl->upval || dyd->label.n > bl->firstlabel))
+        luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
+      closegoto(ls, g, lb);  /* close it */
+      return 1;
+    }
+  }
+  return 0;  /* label not found; cannot close goto */
+}
+
+
+static int newlabelentry (LexState *ls, Labellist *l, TString *name,
+                          int line, int pc) {
+  int n = l->n;
+  luaM_growvector(ls->L, l->arr, n, l->size,
+                  Labeldesc, SHRT_MAX, "labels/gotos");
+  l->arr[n].name = name;
+  l->arr[n].line = line;
+  l->arr[n].nactvar = ls->fs->nactvar;
+  l->arr[n].pc = pc;
+  l->n = n + 1;
+  return n;
+}
+
+
+/*
+** check whether new label 'lb' matches any pending gotos in current
+** block; solves forward jumps
+*/
+static void findgotos (LexState *ls, Labeldesc *lb) {
+  Labellist *gl = &ls->dyd->gt;
+  int i = ls->fs->bl->firstgoto;
+  while (i < gl->n) {
+    if (eqstr(gl->arr[i].name, lb->name))
+      closegoto(ls, i, lb);
+    else
+      i++;
+  }
+}
+
+
+/*
+** export pending gotos to outer level, to check them against
+** outer labels; if the block being exited has upvalues, and
+** the goto exits the scope of any variable (which can be the
+** upvalue), close those variables being exited.
+*/
+static void movegotosout (FuncState *fs, BlockCnt *bl) {
+  int i = bl->firstgoto;
+  Labellist *gl = &fs->ls->dyd->gt;
+  /* correct pending gotos to current block and try to close it
+     with visible labels */
+  while (i < gl->n) {
+    Labeldesc *gt = &gl->arr[i];
+    if (gt->nactvar > bl->nactvar) {
+      if (bl->upval)
+        luaK_patchclose(fs, gt->pc, bl->nactvar);
+      gt->nactvar = bl->nactvar;
+    }
+    if (!findlabel(fs->ls, i))
+      i++;  /* move to next one */
+  }
+}
+
+
+static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) {
+  bl->isloop = isloop;
+  bl->nactvar = fs->nactvar;
+  bl->firstlabel = fs->ls->dyd->label.n;
+  bl->firstgoto = fs->ls->dyd->gt.n;
+  bl->upval = 0;
+  bl->previous = fs->bl;
+  fs->bl = bl;
+  lua_assert(fs->freereg == fs->nactvar);
+}
+
+
+/*
+** create a label named 'break' to resolve break statements
+*/
+static void breaklabel (LexState *ls) {
+  TString *n = luaS_new(ls->L, "break");
+  int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc);
+  findgotos(ls, &ls->dyd->label.arr[l]);
+}
+
+/*
+** generates an error for an undefined 'goto'; choose appropriate
+** message when label name is a reserved word (which can only be 'break')
+*/
+static l_noret undefgoto (LexState *ls, Labeldesc *gt) {
+  const char *msg = isreserved(gt->name)
+                    ? "<%s> at line %d not inside a loop"
+                    : "no visible label '%s' for <goto> at line %d";
+  msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
+  semerror(ls, msg);
+}
+
+
+static void leaveblock (FuncState *fs) {
+  BlockCnt *bl = fs->bl;
+  LexState *ls = fs->ls;
+  if (bl->previous && bl->upval) {
+    /* create a 'jump to here' to close upvalues */
+    int j = luaK_jump(fs);
+    luaK_patchclose(fs, j, bl->nactvar);
+    luaK_patchtohere(fs, j);
+  }
+  if (bl->isloop)
+    breaklabel(ls);  /* close pending breaks */
+  fs->bl = bl->previous;
+  removevars(fs, bl->nactvar);
+  lua_assert(bl->nactvar == fs->nactvar);
+  fs->freereg = fs->nactvar;  /* free registers */
+  ls->dyd->label.n = bl->firstlabel;  /* remove local labels */
+  if (bl->previous)  /* inner block? */
+    movegotosout(fs, bl);  /* update pending gotos to outer block */
+  else if (bl->firstgoto < ls->dyd->gt.n)  /* pending gotos in outer block? */
+    undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]);  /* error */
+}
+
+
+/*
+** adds a new prototype into list of prototypes
+*/
+static Proto *addprototype (LexState *ls) {
+  Proto *clp;
+  lua_State *L = ls->L;
+  FuncState *fs = ls->fs;
+  Proto *f = fs->f;  /* prototype of current function */
+  if (fs->np >= f->sizep) {
+    int oldsize = f->sizep;
+    luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions");
+    while (oldsize < f->sizep)
+      f->p[oldsize++] = NULL;
+  }
+  f->p[fs->np++] = clp = luaF_newproto(L);
+  luaC_objbarrier(L, f, clp);
+  return clp;
+}
+
+
+/*
+** codes instruction to create new closure in parent function.
+** The OP_CLOSURE instruction must use the last available register,
+** so that, if it invokes the GC, the GC knows which registers
+** are in use at that time.
+*/
+static void codeclosure (LexState *ls, expdesc *v) {
+  FuncState *fs = ls->fs->prev;
+  init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
+  luaK_exp2nextreg(fs, v);  /* fix it at the last register */
+}
+
+
+static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
+  Proto *f;
+  fs->prev = ls->fs;  /* linked list of funcstates */
+  fs->ls = ls;
+  ls->fs = fs;
+  fs->pc = 0;
+  fs->lasttarget = 0;
+  fs->jpc = NO_JUMP;
+  fs->freereg = 0;
+  fs->nk = 0;
+  fs->np = 0;
+  fs->nups = 0;
+  fs->nlocvars = 0;
+  fs->nactvar = 0;
+  fs->firstlocal = ls->dyd->actvar.n;
+  fs->bl = NULL;
+  f = fs->f;
+  f->source = ls->source;
+  f->maxstacksize = 2;  /* registers 0/1 are always valid */
+  enterblock(fs, bl, 0);
+}
+
+
+static void close_func (LexState *ls) {
+  lua_State *L = ls->L;
+  FuncState *fs = ls->fs;
+  Proto *f = fs->f;
+  luaK_ret(fs, 0, 0);  /* final return */
+  leaveblock(fs);
+  luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
+  f->sizecode = fs->pc;
+  luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
+  f->sizelineinfo = fs->pc;
+  luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue);
+  f->sizek = fs->nk;
+  luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
+  f->sizep = fs->np;
+  luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
+  f->sizelocvars = fs->nlocvars;
+  luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc);
+  f->sizeupvalues = fs->nups;
+  lua_assert(fs->bl == NULL);
+  ls->fs = fs->prev;
+  luaC_checkGC(L);
+}
+
+
+
+/*============================================================*/
+/* GRAMMAR RULES */
+/*============================================================*/
+
+
+/*
+** check whether current token is in the follow set of a block.
+** 'until' closes syntactical blocks, but do not close scope,
+** so it is handled in separate.
+*/
+static int block_follow (LexState *ls, int withuntil) {
+  switch (ls->t.token) {
+    case TK_ELSE: case TK_ELSEIF:
+    case TK_END: case TK_EOS:
+      return 1;
+    case TK_UNTIL: return withuntil;
+    default: return 0;
+  }
+}
+
+
+static void statlist (LexState *ls) {
+  /* statlist -> { stat [';'] } */
+  while (!block_follow(ls, 1)) {
+    if (ls->t.token == TK_RETURN) {
+      statement(ls);
+      return;  /* 'return' must be last statement */
+    }
+    statement(ls);
+  }
+}
+
+
+static void fieldsel (LexState *ls, expdesc *v) {
+  /* fieldsel -> ['.' | ':'] NAME */
+  FuncState *fs = ls->fs;
+  expdesc key;
+  luaK_exp2anyregup(fs, v);
+  luaX_next(ls);  /* skip the dot or colon */
+  checkname(ls, &key);
+  luaK_indexed(fs, v, &key);
+}
+
+
+static void yindex (LexState *ls, expdesc *v) {
+  /* index -> '[' expr ']' */
+  luaX_next(ls);  /* skip the '[' */
+  expr(ls, v);
+  luaK_exp2val(ls->fs, v);
+  checknext(ls, ']');
+}
+
+
+/*
+** {======================================================================
+** Rules for Constructors
+** =======================================================================
+*/
+
+
+struct ConsControl {
+  expdesc v;  /* last list item read */
+  expdesc *t;  /* table descriptor */
+  int nh;  /* total number of 'record' elements */
+  int na;  /* total number of array elements */
+  int tostore;  /* number of array elements pending to be stored */
+};
+
+
+static void recfield (LexState *ls, struct ConsControl *cc) {
+  /* recfield -> (NAME | '['exp1']') = exp1 */
+  FuncState *fs = ls->fs;
+  int reg = ls->fs->freereg;
+  expdesc key, val;
+  int rkkey;
+  if (ls->t.token == TK_NAME) {
+    checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
+    checkname(ls, &key);
+  }
+  else  /* ls->t.token == '[' */
+    yindex(ls, &key);
+  cc->nh++;
+  checknext(ls, '=');
+  rkkey = luaK_exp2RK(fs, &key);
+  expr(ls, &val);
+  luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val));
+  fs->freereg = reg;  /* free registers */
+}
+
+
+static void closelistfield (FuncState *fs, struct ConsControl *cc) {
+  if (cc->v.k == VVOID) return;  /* there is no list item */
+  luaK_exp2nextreg(fs, &cc->v);
+  cc->v.k = VVOID;
+  if (cc->tostore == LFIELDS_PER_FLUSH) {
+    luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);  /* flush */
+    cc->tostore = 0;  /* no more items pending */
+  }
+}
+
+
+static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
+  if (cc->tostore == 0) return;
+  if (hasmultret(cc->v.k)) {
+    luaK_setmultret(fs, &cc->v);
+    luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET);
+    cc->na--;  /* do not count last expression (unknown number of elements) */
+  }
+  else {
+    if (cc->v.k != VVOID)
+      luaK_exp2nextreg(fs, &cc->v);
+    luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);
+  }
+}
+
+
+static void listfield (LexState *ls, struct ConsControl *cc) {
+  /* listfield -> exp */
+  expr(ls, &cc->v);
+  checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
+  cc->na++;
+  cc->tostore++;
+}
+
+
+static void field (LexState *ls, struct ConsControl *cc) {
+  /* field -> listfield | recfield */
+  switch(ls->t.token) {
+    case TK_NAME: {  /* may be 'listfield' or 'recfield' */
+      if (luaX_lookahead(ls) != '=')  /* expression? */
+        listfield(ls, cc);
+      else
+        recfield(ls, cc);
+      break;
+    }
+    case '[': {
+      recfield(ls, cc);
+      break;
+    }
+    default: {
+      listfield(ls, cc);
+      break;
+    }
+  }
+}
+
+
+static void constructor (LexState *ls, expdesc *t) {
+  /* constructor -> '{' [ field { sep field } [sep] ] '}'
+     sep -> ',' | ';' */
+  FuncState *fs = ls->fs;
+  int line = ls->linenumber;
+  int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
+  struct ConsControl cc;
+  cc.na = cc.nh = cc.tostore = 0;
+  cc.t = t;
+  init_exp(t, VRELOCABLE, pc);
+  init_exp(&cc.v, VVOID, 0);  /* no value (yet) */
+  luaK_exp2nextreg(ls->fs, t);  /* fix it at stack top */
+  checknext(ls, '{');
+  do {
+    lua_assert(cc.v.k == VVOID || cc.tostore > 0);
+    if (ls->t.token == '}') break;
+    closelistfield(fs, &cc);
+    field(ls, &cc);
+  } while (testnext(ls, ',') || testnext(ls, ';'));
+  check_match(ls, '}', '{', line);
+  lastlistfield(fs, &cc);
+  SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
+  SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh));  /* set initial table size */
+}
+
+/* }====================================================================== */
+
+
+
+static void parlist (LexState *ls) {
+  /* parlist -> [ param { ',' param } ] */
+  FuncState *fs = ls->fs;
+  Proto *f = fs->f;
+  int nparams = 0;
+  f->is_vararg = 0;
+  if (ls->t.token != ')') {  /* is 'parlist' not empty? */
+    do {
+      switch (ls->t.token) {
+        case TK_NAME: {  /* param -> NAME */
+          new_localvar(ls, str_checkname(ls));
+          nparams++;
+          break;
+        }
+        case TK_DOTS: {  /* param -> '...' */
+          luaX_next(ls);
+          f->is_vararg = 2;  /* declared vararg */
+          break;
+        }
+        default: luaX_syntaxerror(ls, "<name> or '...' expected");
+      }
+    } while (!f->is_vararg && testnext(ls, ','));
+  }
+  adjustlocalvars(ls, nparams);
+  f->numparams = cast_byte(fs->nactvar);
+  luaK_reserveregs(fs, fs->nactvar);  /* reserve register for parameters */
+}
+
+
+static void body (LexState *ls, expdesc *e, int ismethod, int line) {
+  /* body ->  '(' parlist ')' block END */
+  FuncState new_fs;
+  BlockCnt bl;
+  new_fs.f = addprototype(ls);
+  new_fs.f->linedefined = line;
+  open_func(ls, &new_fs, &bl);
+  checknext(ls, '(');
+  if (ismethod) {
+    new_localvarliteral(ls, "self");  /* create 'self' parameter */
+    adjustlocalvars(ls, 1);
+  }
+  parlist(ls);
+  checknext(ls, ')');
+  statlist(ls);
+  new_fs.f->lastlinedefined = ls->linenumber;
+  check_match(ls, TK_END, TK_FUNCTION, line);
+  codeclosure(ls, e);
+  close_func(ls);
+}
+
+
+static int explist (LexState *ls, expdesc *v) {
+  /* explist -> expr { ',' expr } */
+  int n = 1;  /* at least one expression */
+  expr(ls, v);
+  while (testnext(ls, ',')) {
+    luaK_exp2nextreg(ls->fs, v);
+    expr(ls, v);
+    n++;
+  }
+  return n;
+}
+
+
+static void funcargs (LexState *ls, expdesc *f, int line) {
+  FuncState *fs = ls->fs;
+  expdesc args;
+  int base, nparams;
+  switch (ls->t.token) {
+    case '(': {  /* funcargs -> '(' [ explist ] ')' */
+      luaX_next(ls);
+      if (ls->t.token == ')')  /* arg list is empty? */
+        args.k = VVOID;
+      else {
+        explist(ls, &args);
+        luaK_setmultret(fs, &args);
+      }
+      check_match(ls, ')', '(', line);
+      break;
+    }
+    case '{': {  /* funcargs -> constructor */
+      constructor(ls, &args);
+      break;
+    }
+    case TK_STRING: {  /* funcargs -> STRING */
+      codestring(ls, &args, ls->t.seminfo.ts);
+      luaX_next(ls);  /* must use 'seminfo' before 'next' */
+      break;
+    }
+    default: {
+      luaX_syntaxerror(ls, "function arguments expected");
+    }
+  }
+  lua_assert(f->k == VNONRELOC);
+  base = f->u.info;  /* base register for call */
+  if (hasmultret(args.k))
+    nparams = LUA_MULTRET;  /* open call */
+  else {
+    if (args.k != VVOID)
+      luaK_exp2nextreg(fs, &args);  /* close last argument */
+    nparams = fs->freereg - (base+1);
+  }
+  init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2));
+  luaK_fixline(fs, line);
+  fs->freereg = base+1;  /* call remove function and arguments and leaves
+                            (unless changed) one result */
+}
+
+
+
+
+/*
+** {======================================================================
+** Expression parsing
+** =======================================================================
+*/
+
+
+static void primaryexp (LexState *ls, expdesc *v) {
+  /* primaryexp -> NAME | '(' expr ')' */
+  switch (ls->t.token) {
+    case '(': {
+      int line = ls->linenumber;
+      luaX_next(ls);
+      expr(ls, v);
+      check_match(ls, ')', '(', line);
+      luaK_dischargevars(ls->fs, v);
+      return;
+    }
+    case TK_NAME: {
+      singlevar(ls, v);
+      return;
+    }
+    default: {
+      luaX_syntaxerror(ls, "unexpected symbol");
+    }
+  }
+}
+
+
+static void suffixedexp (LexState *ls, expdesc *v) {
+  /* suffixedexp ->
+       primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
+  FuncState *fs = ls->fs;
+  int line = ls->linenumber;
+  primaryexp(ls, v);
+  for (;;) {
+    switch (ls->t.token) {
+      case '.': {  /* fieldsel */
+        fieldsel(ls, v);
+        break;
+      }
+      case '[': {  /* '[' exp1 ']' */
+        expdesc key;
+        luaK_exp2anyregup(fs, v);
+        yindex(ls, &key);
+        luaK_indexed(fs, v, &key);
+        break;
+      }
+      case ':': {  /* ':' NAME funcargs */
+        expdesc key;
+        luaX_next(ls);
+        checkname(ls, &key);
+        luaK_self(fs, v, &key);
+        funcargs(ls, v, line);
+        break;
+      }
+      case '(': case TK_STRING: case '{': {  /* funcargs */
+        luaK_exp2nextreg(fs, v);
+        funcargs(ls, v, line);
+        break;
+      }
+      default: return;
+    }
+  }
+}
+
+
+static void simpleexp (LexState *ls, expdesc *v) {
+  /* simpleexp -> FLT | INT | STRING | NIL | TRUE | FALSE | ... |
+                  constructor | FUNCTION body | suffixedexp */
+  switch (ls->t.token) {
+    case TK_FLT: {
+      init_exp(v, VKFLT, 0);
+      v->u.nval = ls->t.seminfo.r;
+      break;
+    }
+    case TK_INT: {
+      init_exp(v, VKINT, 0);
+      v->u.ival = ls->t.seminfo.i;
+      break;
+    }
+    case TK_STRING: {
+      codestring(ls, v, ls->t.seminfo.ts);
+      break;
+    }
+    case TK_NIL: {
+      init_exp(v, VNIL, 0);
+      break;
+    }
+    case TK_TRUE: {
+      init_exp(v, VTRUE, 0);
+      break;
+    }
+    case TK_FALSE: {
+      init_exp(v, VFALSE, 0);
+      break;
+    }
+    case TK_DOTS: {  /* vararg */
+      FuncState *fs = ls->fs;
+      check_condition(ls, fs->f->is_vararg,
+                      "cannot use '...' outside a vararg function");
+      fs->f->is_vararg = 1;  /* function actually uses vararg */
+      init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
+      break;
+    }
+    case '{': {  /* constructor */
+      constructor(ls, v);
+      return;
+    }
+    case TK_FUNCTION: {
+      luaX_next(ls);
+      body(ls, v, 0, ls->linenumber);
+      return;
+    }
+    default: {
+      suffixedexp(ls, v);
+      return;
+    }
+  }
+  luaX_next(ls);
+}
+
+
+static UnOpr getunopr (int op) {
+  switch (op) {
+    case TK_NOT: return OPR_NOT;
+    case '-': return OPR_MINUS;
+    case '~': return OPR_BNOT;
+    case '#': return OPR_LEN;
+    default: return OPR_NOUNOPR;
+  }
+}
+
+
+static BinOpr getbinopr (int op) {
+  switch (op) {
+    case '+': return OPR_ADD;
+    case '-': return OPR_SUB;
+    case '*': return OPR_MUL;
+    case '%': return OPR_MOD;
+    case '^': return OPR_POW;
+    case '/': return OPR_DIV;
+    case TK_IDIV: return OPR_IDIV;
+    case '&': return OPR_BAND;
+    case '|': return OPR_BOR;
+    case '~': return OPR_BXOR;
+    case TK_SHL: return OPR_SHL;
+    case TK_SHR: return OPR_SHR;
+    case TK_CONCAT: return OPR_CONCAT;
+    case TK_NE: return OPR_NE;
+    case TK_EQ: return OPR_EQ;
+    case '<': return OPR_LT;
+    case TK_LE: return OPR_LE;
+    case '>': return OPR_GT;
+    case TK_GE: return OPR_GE;
+    case TK_AND: return OPR_AND;
+    case TK_OR: return OPR_OR;
+    default: return OPR_NOBINOPR;
+  }
+}
+
+
+static const struct {
+  lu_byte left;  /* left priority for each binary operator */
+  lu_byte right; /* right priority */
+} priority[] = {  /* ORDER OPR */
+   {10, 10}, {10, 10},           /* '+' '-' */
+   {11, 11}, {11, 11},           /* '*' '%' */
+   {14, 13},                  /* '^' (right associative) */
+   {11, 11}, {11, 11},           /* '/' '//' */
+   {6, 6}, {4, 4}, {5, 5},   /* '&' '|' '~' */
+   {7, 7}, {7, 7},           /* '<<' '>>' */
+   {9, 8},                   /* '..' (right associative) */
+   {3, 3}, {3, 3}, {3, 3},   /* ==, <, <= */
+   {3, 3}, {3, 3}, {3, 3},   /* ~=, >, >= */
+   {2, 2}, {1, 1}            /* and, or */
+};
+
+#define UNARY_PRIORITY	12  /* priority for unary operators */
+
+
+/*
+** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
+** where 'binop' is any binary operator with a priority higher than 'limit'
+*/
+static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
+  BinOpr op;
+  UnOpr uop;
+  enterlevel(ls);
+  uop = getunopr(ls->t.token);
+  if (uop != OPR_NOUNOPR) {
+    int line = ls->linenumber;
+    luaX_next(ls);
+    subexpr(ls, v, UNARY_PRIORITY);
+    luaK_prefix(ls->fs, uop, v, line);
+  }
+  else simpleexp(ls, v);
+  /* expand while operators have priorities higher than 'limit' */
+  op = getbinopr(ls->t.token);
+  while (op != OPR_NOBINOPR && priority[op].left > limit) {
+    expdesc v2;
+    BinOpr nextop;
+    int line = ls->linenumber;
+    luaX_next(ls);
+    luaK_infix(ls->fs, op, v);
+    /* read sub-expression with higher priority */
+    nextop = subexpr(ls, &v2, priority[op].right);
+    luaK_posfix(ls->fs, op, v, &v2, line);
+    op = nextop;
+  }
+  leavelevel(ls);
+  return op;  /* return first untreated operator */
+}
+
+
+static void expr (LexState *ls, expdesc *v) {
+  subexpr(ls, v, 0);
+}
+
+/* }==================================================================== */
+
+
+
+/*
+** {======================================================================
+** Rules for Statements
+** =======================================================================
+*/
+
+
+static void block (LexState *ls) {
+  /* block -> statlist */
+  FuncState *fs = ls->fs;
+  BlockCnt bl;
+  enterblock(fs, &bl, 0);
+  statlist(ls);
+  leaveblock(fs);
+}
+
+
+/*
+** structure to chain all variables in the left-hand side of an
+** assignment
+*/
+struct LHS_assign {
+  struct LHS_assign *prev;
+  expdesc v;  /* variable (global, local, upvalue, or indexed) */
+};
+
+
+/*
+** check whether, in an assignment to an upvalue/local variable, the
+** upvalue/local variable is begin used in a previous assignment to a
+** table. If so, save original upvalue/local value in a safe place and
+** use this safe copy in the previous assignment.
+*/
+static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
+  FuncState *fs = ls->fs;
+  int extra = fs->freereg;  /* eventual position to save local variable */
+  int conflict = 0;
+  for (; lh; lh = lh->prev) {  /* check all previous assignments */
+    if (lh->v.k == VINDEXED) {  /* assigning to a table? */
+      /* table is the upvalue/local being assigned now? */
+      if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) {
+        conflict = 1;
+        lh->v.u.ind.vt = VLOCAL;
+        lh->v.u.ind.t = extra;  /* previous assignment will use safe copy */
+      }
+      /* index is the local being assigned? (index cannot be upvalue) */
+      if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) {
+        conflict = 1;
+        lh->v.u.ind.idx = extra;  /* previous assignment will use safe copy */
+      }
+    }
+  }
+  if (conflict) {
+    /* copy upvalue/local value to a temporary (in position 'extra') */
+    OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
+    luaK_codeABC(fs, op, extra, v->u.info, 0);
+    luaK_reserveregs(fs, 1);
+  }
+}
+
+
+static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
+  expdesc e;
+  check_condition(ls, vkisvar(lh->v.k), "syntax error");
+  if (testnext(ls, ',')) {  /* assignment -> ',' suffixedexp assignment */
+    struct LHS_assign nv;
+    nv.prev = lh;
+    suffixedexp(ls, &nv.v);
+    if (nv.v.k != VINDEXED)
+      check_conflict(ls, lh, &nv.v);
+    checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS,
+                    "C levels");
+    assignment(ls, &nv, nvars+1);
+  }
+  else {  /* assignment -> '=' explist */
+    int nexps;
+    checknext(ls, '=');
+    nexps = explist(ls, &e);
+    if (nexps != nvars) {
+      adjust_assign(ls, nvars, nexps, &e);
+      if (nexps > nvars)
+        ls->fs->freereg -= nexps - nvars;  /* remove extra values */
+    }
+    else {
+      luaK_setoneret(ls->fs, &e);  /* close last expression */
+      luaK_storevar(ls->fs, &lh->v, &e);
+      return;  /* avoid default */
+    }
+  }
+  init_exp(&e, VNONRELOC, ls->fs->freereg-1);  /* default assignment */
+  luaK_storevar(ls->fs, &lh->v, &e);
+}
+
+
+static int cond (LexState *ls) {
+  /* cond -> exp */
+  expdesc v;
+  expr(ls, &v);  /* read condition */
+  if (v.k == VNIL) v.k = VFALSE;  /* 'falses' are all equal here */
+  luaK_goiftrue(ls->fs, &v);
+  return v.f;
+}
+
+
+static void gotostat (LexState *ls, int pc) {
+  int line = ls->linenumber;
+  TString *label;
+  int g;
+  if (testnext(ls, TK_GOTO))
+    label = str_checkname(ls);
+  else {
+    luaX_next(ls);  /* skip break */
+    label = luaS_new(ls->L, "break");
+  }
+  g = newlabelentry(ls, &ls->dyd->gt, label, line, pc);
+  findlabel(ls, g);  /* close it if label already defined */
+}
+
+
+/* check for repeated labels on the same block */
+static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) {
+  int i;
+  for (i = fs->bl->firstlabel; i < ll->n; i++) {
+    if (eqstr(label, ll->arr[i].name)) {
+      const char *msg = luaO_pushfstring(fs->ls->L,
+                          "label '%s' already defined on line %d",
+                          getstr(label), ll->arr[i].line);
+      semerror(fs->ls, msg);
+    }
+  }
+}
+
+
+/* skip no-op statements */
+static void skipnoopstat (LexState *ls) {
+  while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
+    statement(ls);
+}
+
+
+static void labelstat (LexState *ls, TString *label, int line) {
+  /* label -> '::' NAME '::' */
+  FuncState *fs = ls->fs;
+  Labellist *ll = &ls->dyd->label;
+  int l;  /* index of new label being created */
+  checkrepeated(fs, ll, label);  /* check for repeated labels */
+  checknext(ls, TK_DBCOLON);  /* skip double colon */
+  /* create new entry for this label */
+  l = newlabelentry(ls, ll, label, line, luaK_getlabel(fs));
+  skipnoopstat(ls);  /* skip other no-op statements */
+  if (block_follow(ls, 0)) {  /* label is last no-op statement in the block? */
+    /* assume that locals are already out of scope */
+    ll->arr[l].nactvar = fs->bl->nactvar;
+  }
+  findgotos(ls, &ll->arr[l]);
+}
+
+
+static void whilestat (LexState *ls, int line) {
+  /* whilestat -> WHILE cond DO block END */
+  FuncState *fs = ls->fs;
+  int whileinit;
+  int condexit;
+  BlockCnt bl;
+  luaX_next(ls);  /* skip WHILE */
+  whileinit = luaK_getlabel(fs);
+  condexit = cond(ls);
+  enterblock(fs, &bl, 1);
+  checknext(ls, TK_DO);
+  block(ls);
+  luaK_jumpto(fs, whileinit);
+  check_match(ls, TK_END, TK_WHILE, line);
+  leaveblock(fs);
+  luaK_patchtohere(fs, condexit);  /* false conditions finish the loop */
+}
+
+
+static void repeatstat (LexState *ls, int line) {
+  /* repeatstat -> REPEAT block UNTIL cond */
+  int condexit;
+  FuncState *fs = ls->fs;
+  int repeat_init = luaK_getlabel(fs);
+  BlockCnt bl1, bl2;
+  enterblock(fs, &bl1, 1);  /* loop block */
+  enterblock(fs, &bl2, 0);  /* scope block */
+  luaX_next(ls);  /* skip REPEAT */
+  statlist(ls);
+  check_match(ls, TK_UNTIL, TK_REPEAT, line);
+  condexit = cond(ls);  /* read condition (inside scope block) */
+  if (bl2.upval)  /* upvalues? */
+    luaK_patchclose(fs, condexit, bl2.nactvar);
+  leaveblock(fs);  /* finish scope */
+  luaK_patchlist(fs, condexit, repeat_init);  /* close the loop */
+  leaveblock(fs);  /* finish loop */
+}
+
+
+static int exp1 (LexState *ls) {
+  expdesc e;
+  int reg;
+  expr(ls, &e);
+  luaK_exp2nextreg(ls->fs, &e);
+  lua_assert(e.k == VNONRELOC);
+  reg = e.u.info;
+  return reg;
+}
+
+
+static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
+  /* forbody -> DO block */
+  BlockCnt bl;
+  FuncState *fs = ls->fs;
+  int prep, endfor;
+  adjustlocalvars(ls, 3);  /* control variables */
+  checknext(ls, TK_DO);
+  prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
+  enterblock(fs, &bl, 0);  /* scope for declared variables */
+  adjustlocalvars(ls, nvars);
+  luaK_reserveregs(fs, nvars);
+  block(ls);
+  leaveblock(fs);  /* end of scope for declared variables */
+  luaK_patchtohere(fs, prep);
+  if (isnum)  /* numeric for? */
+    endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
+  else {  /* generic for */
+    luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
+    luaK_fixline(fs, line);
+    endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP);
+  }
+  luaK_patchlist(fs, endfor, prep + 1);
+  luaK_fixline(fs, line);
+}
+
+
+static void fornum (LexState *ls, TString *varname, int line) {
+  /* fornum -> NAME = exp1,exp1[,exp1] forbody */
+  FuncState *fs = ls->fs;
+  int base = fs->freereg;
+  new_localvarliteral(ls, "(for index)");
+  new_localvarliteral(ls, "(for limit)");
+  new_localvarliteral(ls, "(for step)");
+  new_localvar(ls, varname);
+  checknext(ls, '=');
+  exp1(ls);  /* initial value */
+  checknext(ls, ',');
+  exp1(ls);  /* limit */
+  if (testnext(ls, ','))
+    exp1(ls);  /* optional step */
+  else {  /* default step = 1 */
+    luaK_codek(fs, fs->freereg, luaK_intK(fs, 1));
+    luaK_reserveregs(fs, 1);
+  }
+  forbody(ls, base, line, 1, 1);
+}
+
+
+static void forlist (LexState *ls, TString *indexname) {
+  /* forlist -> NAME {,NAME} IN explist forbody */
+  FuncState *fs = ls->fs;
+  expdesc e;
+  int nvars = 4;  /* gen, state, control, plus at least one declared var */
+  int line;
+  int base = fs->freereg;
+  /* create control variables */
+  new_localvarliteral(ls, "(for generator)");
+  new_localvarliteral(ls, "(for state)");
+  new_localvarliteral(ls, "(for control)");
+  /* create declared variables */
+  new_localvar(ls, indexname);
+  while (testnext(ls, ',')) {
+    new_localvar(ls, str_checkname(ls));
+    nvars++;
+  }
+  checknext(ls, TK_IN);
+  line = ls->linenumber;
+  adjust_assign(ls, 3, explist(ls, &e), &e);
+  luaK_checkstack(fs, 3);  /* extra space to call generator */
+  forbody(ls, base, line, nvars - 3, 0);
+}
+
+
+static void forstat (LexState *ls, int line) {
+  /* forstat -> FOR (fornum | forlist) END */
+  FuncState *fs = ls->fs;
+  TString *varname;
+  BlockCnt bl;
+  enterblock(fs, &bl, 1);  /* scope for loop and control variables */
+  luaX_next(ls);  /* skip 'for' */
+  varname = str_checkname(ls);  /* first variable name */
+  switch (ls->t.token) {
+    case '=': fornum(ls, varname, line); break;
+    case ',': case TK_IN: forlist(ls, varname); break;
+    default: luaX_syntaxerror(ls, "'=' or 'in' expected");
+  }
+  check_match(ls, TK_END, TK_FOR, line);
+  leaveblock(fs);  /* loop scope ('break' jumps to this point) */
+}
+
+
+static void test_then_block (LexState *ls, int *escapelist) {
+  /* test_then_block -> [IF | ELSEIF] cond THEN block */
+  BlockCnt bl;
+  FuncState *fs = ls->fs;
+  expdesc v;
+  int jf;  /* instruction to skip 'then' code (if condition is false) */
+  luaX_next(ls);  /* skip IF or ELSEIF */
+  expr(ls, &v);  /* read condition */
+  checknext(ls, TK_THEN);
+  if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) {
+    luaK_goiffalse(ls->fs, &v);  /* will jump to label if condition is true */
+    enterblock(fs, &bl, 0);  /* must enter block before 'goto' */
+    gotostat(ls, v.t);  /* handle goto/break */
+    skipnoopstat(ls);  /* skip other no-op statements */
+    if (block_follow(ls, 0)) {  /* 'goto' is the entire block? */
+      leaveblock(fs);
+      return;  /* and that is it */
+    }
+    else  /* must skip over 'then' part if condition is false */
+      jf = luaK_jump(fs);
+  }
+  else {  /* regular case (not goto/break) */
+    luaK_goiftrue(ls->fs, &v);  /* skip over block if condition is false */
+    enterblock(fs, &bl, 0);
+    jf = v.f;
+  }
+  statlist(ls);  /* 'then' part */
+  leaveblock(fs);
+  if (ls->t.token == TK_ELSE ||
+      ls->t.token == TK_ELSEIF)  /* followed by 'else'/'elseif'? */
+    luaK_concat(fs, escapelist, luaK_jump(fs));  /* must jump over it */
+  luaK_patchtohere(fs, jf);
+}
+
+
+static void ifstat (LexState *ls, int line) {
+  /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
+  FuncState *fs = ls->fs;
+  int escapelist = NO_JUMP;  /* exit list for finished parts */
+  test_then_block(ls, &escapelist);  /* IF cond THEN block */
+  while (ls->t.token == TK_ELSEIF)
+    test_then_block(ls, &escapelist);  /* ELSEIF cond THEN block */
+  if (testnext(ls, TK_ELSE))
+    block(ls);  /* 'else' part */
+  check_match(ls, TK_END, TK_IF, line);
+  luaK_patchtohere(fs, escapelist);  /* patch escape list to 'if' end */
+}
+
+
+static void localfunc (LexState *ls) {
+  expdesc b;
+  FuncState *fs = ls->fs;
+  new_localvar(ls, str_checkname(ls));  /* new local variable */
+  adjustlocalvars(ls, 1);  /* enter its scope */
+  body(ls, &b, 0, ls->linenumber);  /* function created in next register */
+  /* debug information will only see the variable after this point! */
+  getlocvar(fs, b.u.info)->startpc = fs->pc;
+}
+
+
+static void localstat (LexState *ls) {
+  /* stat -> LOCAL NAME {',' NAME} ['=' explist] */
+  int nvars = 0;
+  int nexps;
+  expdesc e;
+  do {
+    new_localvar(ls, str_checkname(ls));
+    nvars++;
+  } while (testnext(ls, ','));
+  if (testnext(ls, '='))
+    nexps = explist(ls, &e);
+  else {
+    e.k = VVOID;
+    nexps = 0;
+  }
+  adjust_assign(ls, nvars, nexps, &e);
+  adjustlocalvars(ls, nvars);
+}
+
+
+static int funcname (LexState *ls, expdesc *v) {
+  /* funcname -> NAME {fieldsel} [':' NAME] */
+  int ismethod = 0;
+  singlevar(ls, v);
+  while (ls->t.token == '.')
+    fieldsel(ls, v);
+  if (ls->t.token == ':') {
+    ismethod = 1;
+    fieldsel(ls, v);
+  }
+  return ismethod;
+}
+
+
+static void funcstat (LexState *ls, int line) {
+  /* funcstat -> FUNCTION funcname body */
+  int ismethod;
+  expdesc v, b;
+  luaX_next(ls);  /* skip FUNCTION */
+  ismethod = funcname(ls, &v);
+  body(ls, &b, ismethod, line);
+  luaK_storevar(ls->fs, &v, &b);
+  luaK_fixline(ls->fs, line);  /* definition "happens" in the first line */
+}
+
+
+static void exprstat (LexState *ls) {
+  /* stat -> func | assignment */
+  FuncState *fs = ls->fs;
+  struct LHS_assign v;
+  suffixedexp(ls, &v.v);
+  if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */
+    v.prev = NULL;
+    assignment(ls, &v, 1);
+  }
+  else {  /* stat -> func */
+    check_condition(ls, v.v.k == VCALL, "syntax error");
+    SETARG_C(getinstruction(fs, &v.v), 1);  /* call statement uses no results */
+  }
+}
+
+
+static void retstat (LexState *ls) {
+  /* stat -> RETURN [explist] [';'] */
+  FuncState *fs = ls->fs;
+  expdesc e;
+  int first, nret;  /* registers with returned values */
+  if (block_follow(ls, 1) || ls->t.token == ';')
+    first = nret = 0;  /* return no values */
+  else {
+    nret = explist(ls, &e);  /* optional return values */
+    if (hasmultret(e.k)) {
+      luaK_setmultret(fs, &e);
+      if (e.k == VCALL && nret == 1) {  /* tail call? */
+        SET_OPCODE(getinstruction(fs,&e), OP_TAILCALL);
+        lua_assert(GETARG_A(getinstruction(fs,&e)) == fs->nactvar);
+      }
+      first = fs->nactvar;
+      nret = LUA_MULTRET;  /* return all values */
+    }
+    else {
+      if (nret == 1)  /* only one single value? */
+        first = luaK_exp2anyreg(fs, &e);
+      else {
+        luaK_exp2nextreg(fs, &e);  /* values must go to the stack */
+        first = fs->nactvar;  /* return all active values */
+        lua_assert(nret == fs->freereg - first);
+      }
+    }
+  }
+  luaK_ret(fs, first, nret);
+  testnext(ls, ';');  /* skip optional semicolon */
+}
+
+
+static void statement (LexState *ls) {
+  int line = ls->linenumber;  /* may be needed for error messages */
+  enterlevel(ls);
+  switch (ls->t.token) {
+    case ';': {  /* stat -> ';' (empty statement) */
+      luaX_next(ls);  /* skip ';' */
+      break;
+    }
+    case TK_IF: {  /* stat -> ifstat */
+      ifstat(ls, line);
+      break;
+    }
+    case TK_WHILE: {  /* stat -> whilestat */
+      whilestat(ls, line);
+      break;
+    }
+    case TK_DO: {  /* stat -> DO block END */
+      luaX_next(ls);  /* skip DO */
+      block(ls);
+      check_match(ls, TK_END, TK_DO, line);
+      break;
+    }
+    case TK_FOR: {  /* stat -> forstat */
+      forstat(ls, line);
+      break;
+    }
+    case TK_REPEAT: {  /* stat -> repeatstat */
+      repeatstat(ls, line);
+      break;
+    }
+    case TK_FUNCTION: {  /* stat -> funcstat */
+      funcstat(ls, line);
+      break;
+    }
+    case TK_LOCAL: {  /* stat -> localstat */
+      luaX_next(ls);  /* skip LOCAL */
+      if (testnext(ls, TK_FUNCTION))  /* local function? */
+        localfunc(ls);
+      else
+        localstat(ls);
+      break;
+    }
+    case TK_DBCOLON: {  /* stat -> label */
+      luaX_next(ls);  /* skip double colon */
+      labelstat(ls, str_checkname(ls), line);
+      break;
+    }
+    case TK_RETURN: {  /* stat -> retstat */
+      luaX_next(ls);  /* skip RETURN */
+      retstat(ls);
+      break;
+    }
+    case TK_BREAK:   /* stat -> breakstat */
+    case TK_GOTO: {  /* stat -> 'goto' NAME */
+      gotostat(ls, luaK_jump(ls->fs));
+      break;
+    }
+    default: {  /* stat -> func | assignment */
+      exprstat(ls);
+      break;
+    }
+  }
+  lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
+             ls->fs->freereg >= ls->fs->nactvar);
+  ls->fs->freereg = ls->fs->nactvar;  /* free registers */
+  leavelevel(ls);
+}
+
+/* }====================================================================== */
+
+
+/*
+** compiles the main function, which is a regular vararg function with an
+** upvalue named LUA_ENV
+*/
+static void mainfunc (LexState *ls, FuncState *fs) {
+  BlockCnt bl;
+  expdesc v;
+  open_func(ls, fs, &bl);
+  fs->f->is_vararg = 2;  /* main function is always declared vararg */
+  init_exp(&v, VLOCAL, 0);  /* create and... */
+  newupvalue(fs, ls->envn, &v);  /* ...set environment upvalue */
+  luaX_next(ls);  /* read first token */
+  statlist(ls);  /* parse main body */
+  check(ls, TK_EOS);
+  close_func(ls);
+}
+
+
+LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
+                       Dyndata *dyd, const char *name, int firstchar) {
+  LexState lexstate;
+  FuncState funcstate;
+  LClosure *cl = luaF_newLclosure(L, 1);  /* create main closure */
+  setclLvalue(L, L->top, cl);  /* anchor it (to avoid being collected) */
+  luaD_inctop(L);
+  lexstate.h = luaH_new(L);  /* create table for scanner */
+  sethvalue(L, L->top, lexstate.h);  /* anchor it */
+  luaD_inctop(L);
+  funcstate.f = cl->p = luaF_newproto(L);
+  funcstate.f->source = luaS_new(L, name);  /* create and anchor TString */
+  lua_assert(iswhite(funcstate.f));  /* do not need barrier here */
+  lexstate.buff = buff;
+  lexstate.dyd = dyd;
+  dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
+  luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar);
+  mainfunc(&lexstate, &funcstate);
+  lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
+  /* all scopes should be correctly finished */
+  lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0);
+  L->top--;  /* remove scanner's table */
+  return cl;  /* closure is on the stack, too */
+}
+
diff --git a/src/lparser.h b/src/lparser.h
new file mode 100644
index 0000000..02e9b03
--- /dev/null
+++ b/src/lparser.h
@@ -0,0 +1,133 @@
+/*
+** $Id: lparser.h,v 1.76 2015/12/30 18:16:13 roberto Exp $
+** Lua Parser
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lparser_h
+#define lparser_h
+
+#include "llimits.h"
+#include "lobject.h"
+#include "lzio.h"
+
+
+/*
+** Expression and variable descriptor.
+** Code generation for variables and expressions can be delayed to allow
+** optimizations; An 'expdesc' structure describes a potentially-delayed
+** variable/expression. It has a description of its "main" value plus a
+** list of conditional jumps that can also produce its value (generated
+** by short-circuit operators 'and'/'or').
+*/
+
+/* kinds of variables/expressions */
+typedef enum {
+  VVOID,  /* when 'expdesc' describes the last expression a list,
+             this kind means an empty list (so, no expression) */
+  VNIL,  /* constant nil */
+  VTRUE,  /* constant true */
+  VFALSE,  /* constant false */
+  VK,  /* constant in 'k'; info = index of constant in 'k' */
+  VKFLT,  /* floating constant; nval = numerical float value */
+  VKINT,  /* integer constant; nval = numerical integer value */
+  VNONRELOC,  /* expression has its value in a fixed register;
+                 info = result register */
+  VLOCAL,  /* local variable; info = local register */
+  VUPVAL,  /* upvalue variable; info = index of upvalue in 'upvalues' */
+  VINDEXED,  /* indexed variable;
+                ind.vt = whether 't' is register or upvalue;
+                ind.t = table register or upvalue;
+                ind.idx = key's R/K index */
+  VJMP,  /* expression is a test/comparison;
+            info = pc of corresponding jump instruction */
+  VRELOCABLE,  /* expression can put result in any register;
+                  info = instruction pc */
+  VCALL,  /* expression is a function call; info = instruction pc */
+  VVARARG  /* vararg expression; info = instruction pc */
+} expkind;
+
+
+#define vkisvar(k)	(VLOCAL <= (k) && (k) <= VINDEXED)
+#define vkisinreg(k)	((k) == VNONRELOC || (k) == VLOCAL)
+
+typedef struct expdesc {
+  expkind k;
+  union {
+    lua_Integer ival;    /* for VKINT */
+    lua_Number nval;  /* for VKFLT */
+    int info;  /* for generic use */
+    struct {  /* for indexed variables (VINDEXED) */
+      short idx;  /* index (R/K) */
+      lu_byte t;  /* table (register or upvalue) */
+      lu_byte vt;  /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
+    } ind;
+  } u;
+  int t;  /* patch list of 'exit when true' */
+  int f;  /* patch list of 'exit when false' */
+} expdesc;
+
+
+/* description of active local variable */
+typedef struct Vardesc {
+  short idx;  /* variable index in stack */
+} Vardesc;
+
+
+/* description of pending goto statements and label statements */
+typedef struct Labeldesc {
+  TString *name;  /* label identifier */
+  int pc;  /* position in code */
+  int line;  /* line where it appeared */
+  lu_byte nactvar;  /* local level where it appears in current block */
+} Labeldesc;
+
+
+/* list of labels or gotos */
+typedef struct Labellist {
+  Labeldesc *arr;  /* array */
+  int n;  /* number of entries in use */
+  int size;  /* array size */
+} Labellist;
+
+
+/* dynamic structures used by the parser */
+typedef struct Dyndata {
+  struct {  /* list of active local variables */
+    Vardesc *arr;
+    int n;
+    int size;
+  } actvar;
+  Labellist gt;  /* list of pending gotos */
+  Labellist label;   /* list of active labels */
+} Dyndata;
+
+
+/* control of blocks */
+struct BlockCnt;  /* defined in lparser.c */
+
+
+/* state needed to generate code for a given function */
+typedef struct FuncState {
+  Proto *f;  /* current function header */
+  struct FuncState *prev;  /* enclosing function */
+  struct LexState *ls;  /* lexical state */
+  struct BlockCnt *bl;  /* chain of current blocks */
+  int pc;  /* next position to code (equivalent to 'ncode') */
+  int lasttarget;   /* 'label' of last 'jump label' */
+  int jpc;  /* list of pending jumps to 'pc' */
+  int nk;  /* number of elements in 'k' */
+  int np;  /* number of elements in 'p' */
+  int firstlocal;  /* index of first local var (in Dyndata array) */
+  short nlocvars;  /* number of elements in 'f->locvars' */
+  lu_byte nactvar;  /* number of active local variables */
+  lu_byte nups;  /* number of upvalues */
+  lu_byte freereg;  /* first free register */
+} FuncState;
+
+
+LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
+                                 Dyndata *dyd, const char *name, int firstchar);
+
+
+#endif
diff --git a/src/lprefix.h b/src/lprefix.h
new file mode 100644
index 0000000..02daa83
--- /dev/null
+++ b/src/lprefix.h
@@ -0,0 +1,45 @@
+/*
+** $Id: lprefix.h,v 1.2 2014/12/29 16:54:13 roberto Exp $
+** Definitions for Lua code that must come before any other header file
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lprefix_h
+#define lprefix_h
+
+
+/*
+** Allows POSIX/XSI stuff
+*/
+#if !defined(LUA_USE_C89)	/* { */
+
+#if !defined(_XOPEN_SOURCE)
+#define _XOPEN_SOURCE           600
+#elif _XOPEN_SOURCE == 0
+#undef _XOPEN_SOURCE  /* use -D_XOPEN_SOURCE=0 to undefine it */
+#endif
+
+/*
+** Allows manipulation of large files in gcc and some other compilers
+*/
+#if !defined(LUA_32BITS) && !defined(_FILE_OFFSET_BITS)
+#define _LARGEFILE_SOURCE       1
+#define _FILE_OFFSET_BITS       64
+#endif
+
+#endif				/* } */
+
+
+/*
+** Windows stuff
+*/
+#if defined(_WIN32) 	/* { */
+
+#if !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS  /* avoid warnings about ISO C functions */
+#endif
+
+#endif			/* } */
+
+#endif
+
diff --git a/src/lstate.c b/src/lstate.c
new file mode 100644
index 0000000..9194ac3
--- /dev/null
+++ b/src/lstate.c
@@ -0,0 +1,347 @@
+/*
+** $Id: lstate.c,v 2.133 2015/11/13 12:16:51 roberto Exp $
+** Global State
+** See Copyright Notice in lua.h
+*/
+
+#define lstate_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lapi.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "llex.h"
+#include "lmem.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+
+
+#if !defined(LUAI_GCPAUSE)
+#define LUAI_GCPAUSE	200  /* 200% */
+#endif
+
+#if !defined(LUAI_GCMUL)
+#define LUAI_GCMUL	200 /* GC runs 'twice the speed' of memory allocation */
+#endif
+
+
+/*
+** a macro to help the creation of a unique random seed when a state is
+** created; the seed is used to randomize hashes.
+*/
+#if !defined(luai_makeseed)
+#include <time.h>
+#define luai_makeseed()		cast(unsigned int, time(NULL))
+#endif
+
+
+
+/*
+** thread state + extra space
+*/
+typedef struct LX {
+  lu_byte extra_[LUA_EXTRASPACE];
+  lua_State l;
+} LX;
+
+
+/*
+** Main thread combines a thread state and the global state
+*/
+typedef struct LG {
+  LX l;
+  global_State g;
+} LG;
+
+
+
+#define fromstate(L)	(cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l)))
+
+
+/*
+** Compute an initial seed as random as possible. Rely on Address Space
+** Layout Randomization (if present) to increase randomness..
+*/
+#define addbuff(b,p,e) \
+  { size_t t = cast(size_t, e); \
+    memcpy(b + p, &t, sizeof(t)); p += sizeof(t); }
+
+static unsigned int makeseed (lua_State *L) {
+  char buff[4 * sizeof(size_t)];
+  unsigned int h = luai_makeseed();
+  int p = 0;
+  addbuff(buff, p, L);  /* heap variable */
+  addbuff(buff, p, &h);  /* local variable */
+  addbuff(buff, p, luaO_nilobject);  /* global variable */
+  addbuff(buff, p, &lua_newstate);  /* public function */
+  lua_assert(p == sizeof(buff));
+  return luaS_hash(buff, p, h);
+}
+
+
+/*
+** set GCdebt to a new value keeping the value (totalbytes + GCdebt)
+** invariant (and avoiding underflows in 'totalbytes')
+*/
+void luaE_setdebt (global_State *g, l_mem debt) {
+  l_mem tb = gettotalbytes(g);
+  lua_assert(tb > 0);
+  if (debt < tb - MAX_LMEM)
+    debt = tb - MAX_LMEM;  /* will make 'totalbytes == MAX_LMEM' */
+  g->totalbytes = tb - debt;
+  g->GCdebt = debt;
+}
+
+
+CallInfo *luaE_extendCI (lua_State *L) {
+  CallInfo *ci = luaM_new(L, CallInfo);
+  lua_assert(L->ci->next == NULL);
+  L->ci->next = ci;
+  ci->previous = L->ci;
+  ci->next = NULL;
+  L->nci++;
+  return ci;
+}
+
+
+/*
+** free all CallInfo structures not in use by a thread
+*/
+void luaE_freeCI (lua_State *L) {
+  CallInfo *ci = L->ci;
+  CallInfo *next = ci->next;
+  ci->next = NULL;
+  while ((ci = next) != NULL) {
+    next = ci->next;
+    luaM_free(L, ci);
+    L->nci--;
+  }
+}
+
+
+/*
+** free half of the CallInfo structures not in use by a thread
+*/
+void luaE_shrinkCI (lua_State *L) {
+  CallInfo *ci = L->ci;
+  CallInfo *next2;  /* next's next */
+  /* while there are two nexts */
+  while (ci->next != NULL && (next2 = ci->next->next) != NULL) {
+    luaM_free(L, ci->next);  /* free next */
+    L->nci--;
+    ci->next = next2;  /* remove 'next' from the list */
+    next2->previous = ci;
+    ci = next2;  /* keep next's next */
+  }
+}
+
+
+static void stack_init (lua_State *L1, lua_State *L) {
+  int i; CallInfo *ci;
+  /* initialize stack array */
+  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue);
+  L1->stacksize = BASIC_STACK_SIZE;
+  for (i = 0; i < BASIC_STACK_SIZE; i++)
+    setnilvalue(L1->stack + i);  /* erase new stack */
+  L1->top = L1->stack;
+  L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK;
+  /* initialize first ci */
+  ci = &L1->base_ci;
+  ci->next = ci->previous = NULL;
+  ci->callstatus = 0;
+  ci->func = L1->top;
+  setnilvalue(L1->top++);  /* 'function' entry for this 'ci' */
+  ci->top = L1->top + LUA_MINSTACK;
+  L1->ci = ci;
+}
+
+
+static void freestack (lua_State *L) {
+  if (L->stack == NULL)
+    return;  /* stack not completely built yet */
+  L->ci = &L->base_ci;  /* free the entire 'ci' list */
+  luaE_freeCI(L);
+  lua_assert(L->nci == 0);
+  luaM_freearray(L, L->stack, L->stacksize);  /* free stack array */
+}
+
+
+/*
+** Create registry table and its predefined values
+*/
+static void init_registry (lua_State *L, global_State *g) {
+  TValue temp;
+  /* create registry */
+  Table *registry = luaH_new(L);
+  sethvalue(L, &g->l_registry, registry);
+  luaH_resize(L, registry, LUA_RIDX_LAST, 0);
+  /* registry[LUA_RIDX_MAINTHREAD] = L */
+  setthvalue(L, &temp, L);  /* temp = L */
+  luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &temp);
+  /* registry[LUA_RIDX_GLOBALS] = table of globals */
+  sethvalue(L, &temp, luaH_new(L));  /* temp = new table (global table) */
+  luaH_setint(L, registry, LUA_RIDX_GLOBALS, &temp);
+}
+
+
+/*
+** open parts of the state that may cause memory-allocation errors.
+** ('g->version' != NULL flags that the state was completely build)
+*/
+static void f_luaopen (lua_State *L, void *ud) {
+  global_State *g = G(L);
+  UNUSED(ud);
+  stack_init(L, L);  /* init stack */
+  init_registry(L, g);
+  luaS_init(L);
+  luaT_init(L);
+  luaX_init(L);
+  g->gcrunning = 1;  /* allow gc */
+  g->version = lua_version(NULL);
+  luai_userstateopen(L);
+}
+
+
+/*
+** preinitialize a thread with consistent values without allocating
+** any memory (to avoid errors)
+*/
+static void preinit_thread (lua_State *L, global_State *g) {
+  G(L) = g;
+  L->stack = NULL;
+  L->ci = NULL;
+  L->nci = 0;
+  L->stacksize = 0;
+  L->twups = L;  /* thread has no upvalues */
+  L->errorJmp = NULL;
+  L->nCcalls = 0;
+  L->hook = NULL;
+  L->hookmask = 0;
+  L->basehookcount = 0;
+  L->allowhook = 1;
+  resethookcount(L);
+  L->openupval = NULL;
+  L->nny = 1;
+  L->status = LUA_OK;
+  L->errfunc = 0;
+}
+
+
+static void close_state (lua_State *L) {
+  global_State *g = G(L);
+  luaF_close(L, L->stack);  /* close all upvalues for this thread */
+  luaC_freeallobjects(L);  /* collect all objects */
+  if (g->version)  /* closing a fully built state? */
+    luai_userstateclose(L);
+  luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
+  freestack(L);
+  lua_assert(gettotalbytes(g) == sizeof(LG));
+  (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0);  /* free main block */
+}
+
+
+LUA_API lua_State *lua_newthread (lua_State *L) {
+  global_State *g = G(L);
+  lua_State *L1;
+  lua_lock(L);
+  luaC_checkGC(L);
+  /* create new thread */
+  L1 = &cast(LX *, luaM_newobject(L, LUA_TTHREAD, sizeof(LX)))->l;
+  L1->marked = luaC_white(g);
+  L1->tt = LUA_TTHREAD;
+  /* link it on list 'allgc' */
+  L1->next = g->allgc;
+  g->allgc = obj2gco(L1);
+  /* anchor it on L stack */
+  setthvalue(L, L->top, L1);
+  api_incr_top(L);
+  preinit_thread(L1, g);
+  L1->hookmask = L->hookmask;
+  L1->basehookcount = L->basehookcount;
+  L1->hook = L->hook;
+  resethookcount(L1);
+  /* initialize L1 extra space */
+  memcpy(lua_getextraspace(L1), lua_getextraspace(g->mainthread),
+         LUA_EXTRASPACE);
+  luai_userstatethread(L, L1);
+  stack_init(L1, L);  /* init stack */
+  lua_unlock(L);
+  return L1;
+}
+
+
+void luaE_freethread (lua_State *L, lua_State *L1) {
+  LX *l = fromstate(L1);
+  luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
+  lua_assert(L1->openupval == NULL);
+  luai_userstatefree(L, L1);
+  freestack(L1);
+  luaM_free(L, l);
+}
+
+
+LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
+  int i;
+  lua_State *L;
+  global_State *g;
+  LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG)));
+  if (l == NULL) return NULL;
+  L = &l->l.l;
+  g = &l->g;
+  L->next = NULL;
+  L->tt = LUA_TTHREAD;
+  g->currentwhite = bitmask(WHITE0BIT);
+  L->marked = luaC_white(g);
+  preinit_thread(L, g);
+  g->frealloc = f;
+  g->ud = ud;
+  g->mainthread = L;
+  g->seed = makeseed(L);
+  g->gcrunning = 0;  /* no GC while building state */
+  g->GCestimate = 0;
+  g->strt.size = g->strt.nuse = 0;
+  g->strt.hash = NULL;
+  setnilvalue(&g->l_registry);
+  g->panic = NULL;
+  g->version = NULL;
+  g->gcstate = GCSpause;
+  g->gckind = KGC_NORMAL;
+  g->allgc = g->finobj = g->tobefnz = g->fixedgc = NULL;
+  g->sweepgc = NULL;
+  g->gray = g->grayagain = NULL;
+  g->weak = g->ephemeron = g->allweak = NULL;
+  g->twups = NULL;
+  g->totalbytes = sizeof(LG);
+  g->GCdebt = 0;
+  g->gcfinnum = 0;
+  g->gcpause = LUAI_GCPAUSE;
+  g->gcstepmul = LUAI_GCMUL;
+  for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL;
+  if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) {
+    /* memory allocation error: free partial state */
+    close_state(L);
+    L = NULL;
+  }
+  return L;
+}
+
+
+LUA_API void lua_close (lua_State *L) {
+  L = G(L)->mainthread;  /* only the main thread can be closed */
+  lua_lock(L);
+  close_state(L);
+}
+
+
diff --git a/src/lstate.h b/src/lstate.h
new file mode 100644
index 0000000..b3033be
--- /dev/null
+++ b/src/lstate.h
@@ -0,0 +1,234 @@
+/*
+** $Id: lstate.h,v 2.130 2015/12/16 16:39:38 roberto Exp $
+** Global State
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lstate_h
+#define lstate_h
+
+#include "lua.h"
+
+#include "lobject.h"
+#include "ltm.h"
+#include "lzio.h"
+
+
+/*
+
+** Some notes about garbage-collected objects: All objects in Lua must
+** be kept somehow accessible until being freed, so all objects always
+** belong to one (and only one) of these lists, using field 'next' of
+** the 'CommonHeader' for the link:
+**
+** 'allgc': all objects not marked for finalization;
+** 'finobj': all objects marked for finalization;
+** 'tobefnz': all objects ready to be finalized; 
+** 'fixedgc': all objects that are not to be collected (currently
+** only small strings, such as reserved words).
+
+*/
+
+
+struct lua_longjmp;  /* defined in ldo.c */
+
+
+/*
+** Atomic type (relative to signals) to better ensure that 'lua_sethook' 
+** is thread safe
+*/
+#if !defined(l_signalT)
+#include <signal.h>
+#define l_signalT	sig_atomic_t
+#endif
+
+
+/* extra stack space to handle TM calls and some other extras */
+#define EXTRA_STACK   5
+
+
+#define BASIC_STACK_SIZE        (2*LUA_MINSTACK)
+
+
+/* kinds of Garbage Collection */
+#define KGC_NORMAL	0
+#define KGC_EMERGENCY	1	/* gc was forced by an allocation failure */
+
+
+typedef struct stringtable {
+  TString **hash;
+  int nuse;  /* number of elements */
+  int size;
+} stringtable;
+
+
+/*
+** Information about a call.
+** When a thread yields, 'func' is adjusted to pretend that the
+** top function has only the yielded values in its stack; in that
+** case, the actual 'func' value is saved in field 'extra'. 
+** When a function calls another with a continuation, 'extra' keeps
+** the function index so that, in case of errors, the continuation
+** function can be called with the correct top.
+*/
+typedef struct CallInfo {
+  StkId func;  /* function index in the stack */
+  StkId	top;  /* top for this function */
+  struct CallInfo *previous, *next;  /* dynamic call link */
+  union {
+    struct {  /* only for Lua functions */
+      StkId base;  /* base for this function */
+      const Instruction *savedpc;
+    } l;
+    struct {  /* only for C functions */
+      lua_KFunction k;  /* continuation in case of yields */
+      ptrdiff_t old_errfunc;
+      lua_KContext ctx;  /* context info. in case of yields */
+    } c;
+  } u;
+  ptrdiff_t extra;
+  short nresults;  /* expected number of results from this function */
+  lu_byte callstatus;
+} CallInfo;
+
+
+/*
+** Bits in CallInfo status
+*/
+#define CIST_OAH	(1<<0)	/* original value of 'allowhook' */
+#define CIST_LUA	(1<<1)	/* call is running a Lua function */
+#define CIST_HOOKED	(1<<2)	/* call is running a debug hook */
+#define CIST_FRESH	(1<<3)	/* call is running on a fresh invocation
+                                   of luaV_execute */
+#define CIST_YPCALL	(1<<4)	/* call is a yieldable protected call */
+#define CIST_TAIL	(1<<5)	/* call was tail called */
+#define CIST_HOOKYIELD	(1<<6)	/* last hook called yielded */
+#define CIST_LEQ	(1<<7)  /* using __lt for __le */
+
+#define isLua(ci)	((ci)->callstatus & CIST_LUA)
+
+/* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */
+#define setoah(st,v)	((st) = ((st) & ~CIST_OAH) | (v))
+#define getoah(st)	((st) & CIST_OAH)
+
+
+/*
+** 'global state', shared by all threads of this state
+*/
+typedef struct global_State {
+  lua_Alloc frealloc;  /* function to reallocate memory */
+  void *ud;         /* auxiliary data to 'frealloc' */
+  l_mem totalbytes;  /* number of bytes currently allocated - GCdebt */
+  l_mem GCdebt;  /* bytes allocated not yet compensated by the collector */
+  lu_mem GCmemtrav;  /* memory traversed by the GC */
+  lu_mem GCestimate;  /* an estimate of the non-garbage memory in use */
+  stringtable strt;  /* hash table for strings */
+  TValue l_registry;
+  unsigned int seed;  /* randomized seed for hashes */
+  lu_byte currentwhite;
+  lu_byte gcstate;  /* state of garbage collector */
+  lu_byte gckind;  /* kind of GC running */
+  lu_byte gcrunning;  /* true if GC is running */
+  GCObject *allgc;  /* list of all collectable objects */
+  GCObject **sweepgc;  /* current position of sweep in list */
+  GCObject *finobj;  /* list of collectable objects with finalizers */
+  GCObject *gray;  /* list of gray objects */
+  GCObject *grayagain;  /* list of objects to be traversed atomically */
+  GCObject *weak;  /* list of tables with weak values */
+  GCObject *ephemeron;  /* list of ephemeron tables (weak keys) */
+  GCObject *allweak;  /* list of all-weak tables */
+  GCObject *tobefnz;  /* list of userdata to be GC */
+  GCObject *fixedgc;  /* list of objects not to be collected */
+  struct lua_State *twups;  /* list of threads with open upvalues */
+  unsigned int gcfinnum;  /* number of finalizers to call in each GC step */
+  int gcpause;  /* size of pause between successive GCs */
+  int gcstepmul;  /* GC 'granularity' */
+  lua_CFunction panic;  /* to be called in unprotected errors */
+  struct lua_State *mainthread;
+  const lua_Number *version;  /* pointer to version number */
+  TString *memerrmsg;  /* memory-error message */
+  TString *tmname[TM_N];  /* array with tag-method names */
+  struct Table *mt[LUA_NUMTAGS];  /* metatables for basic types */
+  TString *strcache[STRCACHE_N][STRCACHE_M];  /* cache for strings in API */
+} global_State;
+
+
+/*
+** 'per thread' state
+*/
+struct lua_State {
+  CommonHeader;
+  unsigned short nci;  /* number of items in 'ci' list */
+  lu_byte status;
+  StkId top;  /* first free slot in the stack */
+  global_State *l_G;
+  CallInfo *ci;  /* call info for current function */
+  const Instruction *oldpc;  /* last pc traced */
+  StkId stack_last;  /* last free slot in the stack */
+  StkId stack;  /* stack base */
+  UpVal *openupval;  /* list of open upvalues in this stack */
+  GCObject *gclist;
+  struct lua_State *twups;  /* list of threads with open upvalues */
+  struct lua_longjmp *errorJmp;  /* current error recover point */
+  CallInfo base_ci;  /* CallInfo for first level (C calling Lua) */
+  volatile lua_Hook hook;
+  ptrdiff_t errfunc;  /* current error handling function (stack index) */
+  int stacksize;
+  int basehookcount;
+  int hookcount;
+  unsigned short nny;  /* number of non-yieldable calls in stack */
+  unsigned short nCcalls;  /* number of nested C calls */
+  l_signalT hookmask;
+  lu_byte allowhook;
+};
+
+
+#define G(L)	(L->l_G)
+
+
+/*
+** Union of all collectable objects (only for conversions)
+*/
+union GCUnion {
+  GCObject gc;  /* common header */
+  struct TString ts;
+  struct Udata u;
+  union Closure cl;
+  struct Table h;
+  struct Proto p;
+  struct lua_State th;  /* thread */
+};
+
+
+#define cast_u(o)	cast(union GCUnion *, (o))
+
+/* macros to convert a GCObject into a specific value */
+#define gco2ts(o)  \
+	check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts))
+#define gco2u(o)  check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u))
+#define gco2lcl(o)  check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l))
+#define gco2ccl(o)  check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c))
+#define gco2cl(o)  \
+	check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl))
+#define gco2t(o)  check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h))
+#define gco2p(o)  check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p))
+#define gco2th(o)  check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th))
+
+
+/* macro to convert a Lua object into a GCObject */
+#define obj2gco(v) \
+	check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc)))
+
+
+/* actual number of total bytes allocated */
+#define gettotalbytes(g)	cast(lu_mem, (g)->totalbytes + (g)->GCdebt)
+
+LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt);
+LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
+LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);
+LUAI_FUNC void luaE_freeCI (lua_State *L);
+LUAI_FUNC void luaE_shrinkCI (lua_State *L);
+
+
+#endif
+
diff --git a/src/lstring.c b/src/lstring.c
new file mode 100644
index 0000000..9351766
--- /dev/null
+++ b/src/lstring.c
@@ -0,0 +1,248 @@
+/*
+** $Id: lstring.c,v 2.56 2015/11/23 11:32:51 roberto Exp $
+** String table (keeps all strings handled by Lua)
+** See Copyright Notice in lua.h
+*/
+
+#define lstring_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+
+
+#define MEMERRMSG       "not enough memory"
+
+
+/*
+** Lua will use at most ~(2^LUAI_HASHLIMIT) bytes from a string to
+** compute its hash
+*/
+#if !defined(LUAI_HASHLIMIT)
+#define LUAI_HASHLIMIT		5
+#endif
+
+
+/*
+** equality for long strings
+*/
+int luaS_eqlngstr (TString *a, TString *b) {
+  size_t len = a->u.lnglen;
+  lua_assert(a->tt == LUA_TLNGSTR && b->tt == LUA_TLNGSTR);
+  return (a == b) ||  /* same instance or... */
+    ((len == b->u.lnglen) &&  /* equal length and ... */
+     (memcmp(getstr(a), getstr(b), len) == 0));  /* equal contents */
+}
+
+
+unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
+  unsigned int h = seed ^ cast(unsigned int, l);
+  size_t step = (l >> LUAI_HASHLIMIT) + 1;
+  for (; l >= step; l -= step)
+    h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1]));
+  return h;
+}
+
+
+unsigned int luaS_hashlongstr (TString *ts) {
+  lua_assert(ts->tt == LUA_TLNGSTR);
+  if (ts->extra == 0) {  /* no hash? */
+    ts->hash = luaS_hash(getstr(ts), ts->u.lnglen, ts->hash);
+    ts->extra = 1;  /* now it has its hash */
+  }
+  return ts->hash;
+}
+
+
+/*
+** resizes the string table
+*/
+void luaS_resize (lua_State *L, int newsize) {
+  int i;
+  stringtable *tb = &G(L)->strt;
+  if (newsize > tb->size) {  /* grow table if needed */
+    luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *);
+    for (i = tb->size; i < newsize; i++)
+      tb->hash[i] = NULL;
+  }
+  for (i = 0; i < tb->size; i++) {  /* rehash */
+    TString *p = tb->hash[i];
+    tb->hash[i] = NULL;
+    while (p) {  /* for each node in the list */
+      TString *hnext = p->u.hnext;  /* save next */
+      unsigned int h = lmod(p->hash, newsize);  /* new position */
+      p->u.hnext = tb->hash[h];  /* chain it */
+      tb->hash[h] = p;
+      p = hnext;
+    }
+  }
+  if (newsize < tb->size) {  /* shrink table if needed */
+    /* vanishing slice should be empty */
+    lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL);
+    luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *);
+  }
+  tb->size = newsize;
+}
+
+
+/*
+** Clear API string cache. (Entries cannot be empty, so fill them with
+** a non-collectable string.)
+*/
+void luaS_clearcache (global_State *g) {
+  int i, j;
+  for (i = 0; i < STRCACHE_N; i++)
+    for (j = 0; j < STRCACHE_M; j++) {
+    if (iswhite(g->strcache[i][j]))  /* will entry be collected? */
+      g->strcache[i][j] = g->memerrmsg;  /* replace it with something fixed */
+    }
+}
+
+
+/*
+** Initialize the string table and the string cache
+*/
+void luaS_init (lua_State *L) {
+  global_State *g = G(L);
+  int i, j;
+  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
+  /* pre-create memory-error message */
+  g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
+  luaC_fix(L, obj2gco(g->memerrmsg));  /* it should never be collected */
+  for (i = 0; i < STRCACHE_N; i++)  /* fill cache with valid strings */
+    for (j = 0; j < STRCACHE_M; j++)
+      g->strcache[i][j] = g->memerrmsg;
+}
+
+
+
+/*
+** creates a new string object
+*/
+static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) {
+  TString *ts;
+  GCObject *o;
+  size_t totalsize;  /* total size of TString object */
+  totalsize = sizelstring(l);
+  o = luaC_newobj(L, tag, totalsize);
+  ts = gco2ts(o);
+  ts->hash = h;
+  ts->extra = 0;
+  getstr(ts)[l] = '\0';  /* ending 0 */
+  return ts;
+}
+
+
+TString *luaS_createlngstrobj (lua_State *L, size_t l) {
+  TString *ts = createstrobj(L, l, LUA_TLNGSTR, G(L)->seed);
+  ts->u.lnglen = l;
+  return ts;
+}
+
+
+void luaS_remove (lua_State *L, TString *ts) {
+  stringtable *tb = &G(L)->strt;
+  TString **p = &tb->hash[lmod(ts->hash, tb->size)];
+  while (*p != ts)  /* find previous element */
+    p = &(*p)->u.hnext;
+  *p = (*p)->u.hnext;  /* remove element from its list */
+  tb->nuse--;
+}
+
+
+/*
+** checks whether short string exists and reuses it or creates a new one
+*/
+static TString *internshrstr (lua_State *L, const char *str, size_t l) {
+  TString *ts;
+  global_State *g = G(L);
+  unsigned int h = luaS_hash(str, l, g->seed);
+  TString **list = &g->strt.hash[lmod(h, g->strt.size)];
+  lua_assert(str != NULL);  /* otherwise 'memcmp'/'memcpy' are undefined */
+  for (ts = *list; ts != NULL; ts = ts->u.hnext) {
+    if (l == ts->shrlen &&
+        (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
+      /* found! */
+      if (isdead(g, ts))  /* dead (but not collected yet)? */
+        changewhite(ts);  /* resurrect it */
+      return ts;
+    }
+  }
+  if (g->strt.nuse >= g->strt.size && g->strt.size <= MAX_INT/2) {
+    luaS_resize(L, g->strt.size * 2);
+    list = &g->strt.hash[lmod(h, g->strt.size)];  /* recompute with new size */
+  }
+  ts = createstrobj(L, l, LUA_TSHRSTR, h);
+  memcpy(getstr(ts), str, l * sizeof(char));
+  ts->shrlen = cast_byte(l);
+  ts->u.hnext = *list;
+  *list = ts;
+  g->strt.nuse++;
+  return ts;
+}
+
+
+/*
+** new string (with explicit length)
+*/
+TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
+  if (l <= LUAI_MAXSHORTLEN)  /* short string? */
+    return internshrstr(L, str, l);
+  else {
+    TString *ts;
+    if (l >= (MAX_SIZE - sizeof(TString))/sizeof(char))
+      luaM_toobig(L);
+    ts = luaS_createlngstrobj(L, l);
+    memcpy(getstr(ts), str, l * sizeof(char));
+    return ts;
+  }
+}
+
+
+/*
+** Create or reuse a zero-terminated string, first checking in the
+** cache (using the string address as a key). The cache can contain
+** only zero-terminated strings, so it is safe to use 'strcmp' to
+** check hits.
+*/
+TString *luaS_new (lua_State *L, const char *str) {
+  unsigned int i = point2uint(str) % STRCACHE_N;  /* hash */
+  int j;
+  TString **p = G(L)->strcache[i];
+  for (j = 0; j < STRCACHE_M; j++) {
+    if (strcmp(str, getstr(p[j])) == 0)  /* hit? */
+      return p[j];  /* that is it */
+  }
+  /* normal route */
+  for (j = STRCACHE_M - 1; j > 0; j--)
+    p[j] = p[j - 1];  /* move out last element */
+  /* new element is first in the list */
+  p[0] = luaS_newlstr(L, str, strlen(str));
+  return p[0];
+}
+
+
+Udata *luaS_newudata (lua_State *L, size_t s) {
+  Udata *u;
+  GCObject *o;
+  if (s > MAX_SIZE - sizeof(Udata))
+    luaM_toobig(L);
+  o = luaC_newobj(L, LUA_TUSERDATA, sizeludata(s));
+  u = gco2u(o);
+  u->len = s;
+  u->metatable = NULL;
+  setuservalue(L, u, luaO_nilobject);
+  return u;
+}
+
diff --git a/src/lstring.h b/src/lstring.h
new file mode 100644
index 0000000..27efd20
--- /dev/null
+++ b/src/lstring.h
@@ -0,0 +1,49 @@
+/*
+** $Id: lstring.h,v 1.61 2015/11/03 15:36:01 roberto Exp $
+** String table (keep all strings handled by Lua)
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lstring_h
+#define lstring_h
+
+#include "lgc.h"
+#include "lobject.h"
+#include "lstate.h"
+
+
+#define sizelstring(l)  (sizeof(union UTString) + ((l) + 1) * sizeof(char))
+
+#define sizeludata(l)	(sizeof(union UUdata) + (l))
+#define sizeudata(u)	sizeludata((u)->len)
+
+#define luaS_newliteral(L, s)	(luaS_newlstr(L, "" s, \
+                                 (sizeof(s)/sizeof(char))-1))
+
+
+/*
+** test whether a string is a reserved word
+*/
+#define isreserved(s)	((s)->tt == LUA_TSHRSTR && (s)->extra > 0)
+
+
+/*
+** equality for short strings, which are always internalized
+*/
+#define eqshrstr(a,b)	check_exp((a)->tt == LUA_TSHRSTR, (a) == (b))
+
+
+LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l, unsigned int seed);
+LUAI_FUNC unsigned int luaS_hashlongstr (TString *ts);
+LUAI_FUNC int luaS_eqlngstr (TString *a, TString *b);
+LUAI_FUNC void luaS_resize (lua_State *L, int newsize);
+LUAI_FUNC void luaS_clearcache (global_State *g);
+LUAI_FUNC void luaS_init (lua_State *L);
+LUAI_FUNC void luaS_remove (lua_State *L, TString *ts);
+LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s);
+LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l);
+LUAI_FUNC TString *luaS_new (lua_State *L, const char *str);
+LUAI_FUNC TString *luaS_createlngstrobj (lua_State *L, size_t l);
+
+
+#endif
diff --git a/src/lstrlib.c b/src/lstrlib.c
new file mode 100644
index 0000000..12264f8
--- /dev/null
+++ b/src/lstrlib.c
@@ -0,0 +1,1582 @@
+/*
+** $Id: lstrlib.c,v 1.251 2016/05/20 14:13:21 roberto Exp $
+** Standard library for string operations and pattern-matching
+** See Copyright Notice in lua.h
+*/
+
+#define lstrlib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <ctype.h>
+#include <float.h>
+#include <limits.h>
+#include <locale.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** maximum number of captures that a pattern can do during
+** pattern-matching. This limit is arbitrary, but must fit in
+** an unsigned char.
+*/
+#if !defined(LUA_MAXCAPTURES)
+#define LUA_MAXCAPTURES		32
+#endif
+
+
+/* macro to 'unsign' a character */
+#define uchar(c)	((unsigned char)(c))
+
+
+/*
+** Some sizes are better limited to fit in 'int', but must also fit in
+** 'size_t'. (We assume that 'lua_Integer' cannot be smaller than 'int'.)
+*/
+#define MAX_SIZET	((size_t)(~(size_t)0))
+
+#define MAXSIZE  \
+	(sizeof(size_t) < sizeof(int) ? MAX_SIZET : (size_t)(INT_MAX))
+
+
+
+
+static int str_len (lua_State *L) {
+  size_t l;
+  luaL_checklstring(L, 1, &l);
+  lua_pushinteger(L, (lua_Integer)l);
+  return 1;
+}
+
+
+/* translate a relative string position: negative means back from end */
+static lua_Integer posrelat (lua_Integer pos, size_t len) {
+  if (pos >= 0) return pos;
+  else if (0u - (size_t)pos > len) return 0;
+  else return (lua_Integer)len + pos + 1;
+}
+
+
+static int str_sub (lua_State *L) {
+  size_t l;
+  const char *s = luaL_checklstring(L, 1, &l);
+  lua_Integer start = posrelat(luaL_checkinteger(L, 2), l);
+  lua_Integer end = posrelat(luaL_optinteger(L, 3, -1), l);
+  if (start < 1) start = 1;
+  if (end > (lua_Integer)l) end = l;
+  if (start <= end)
+    lua_pushlstring(L, s + start - 1, (size_t)(end - start) + 1);
+  else lua_pushliteral(L, "");
+  return 1;
+}
+
+
+static int str_reverse (lua_State *L) {
+  size_t l, i;
+  luaL_Buffer b;
+  const char *s = luaL_checklstring(L, 1, &l);
+  char *p = luaL_buffinitsize(L, &b, l);
+  for (i = 0; i < l; i++)
+    p[i] = s[l - i - 1];
+  luaL_pushresultsize(&b, l);
+  return 1;
+}
+
+
+static int str_lower (lua_State *L) {
+  size_t l;
+  size_t i;
+  luaL_Buffer b;
+  const char *s = luaL_checklstring(L, 1, &l);
+  char *p = luaL_buffinitsize(L, &b, l);
+  for (i=0; i<l; i++)
+    p[i] = tolower(uchar(s[i]));
+  luaL_pushresultsize(&b, l);
+  return 1;
+}
+
+
+static int str_upper (lua_State *L) {
+  size_t l;
+  size_t i;
+  luaL_Buffer b;
+  const char *s = luaL_checklstring(L, 1, &l);
+  char *p = luaL_buffinitsize(L, &b, l);
+  for (i=0; i<l; i++)
+    p[i] = toupper(uchar(s[i]));
+  luaL_pushresultsize(&b, l);
+  return 1;
+}
+
+
+static int str_rep (lua_State *L) {
+  size_t l, lsep;
+  const char *s = luaL_checklstring(L, 1, &l);
+  lua_Integer n = luaL_checkinteger(L, 2);
+  const char *sep = luaL_optlstring(L, 3, "", &lsep);
+  if (n <= 0) lua_pushliteral(L, "");
+  else if (l + lsep < l || l + lsep > MAXSIZE / n)  /* may overflow? */
+    return luaL_error(L, "resulting string too large");
+  else {
+    size_t totallen = (size_t)n * l + (size_t)(n - 1) * lsep;
+    luaL_Buffer b;
+    char *p = luaL_buffinitsize(L, &b, totallen);
+    while (n-- > 1) {  /* first n-1 copies (followed by separator) */
+      memcpy(p, s, l * sizeof(char)); p += l;
+      if (lsep > 0) {  /* empty 'memcpy' is not that cheap */
+        memcpy(p, sep, lsep * sizeof(char));
+        p += lsep;
+      }
+    }
+    memcpy(p, s, l * sizeof(char));  /* last copy (not followed by separator) */
+    luaL_pushresultsize(&b, totallen);
+  }
+  return 1;
+}
+
+
+static int str_byte (lua_State *L) {
+  size_t l;
+  const char *s = luaL_checklstring(L, 1, &l);
+  lua_Integer posi = posrelat(luaL_optinteger(L, 2, 1), l);
+  lua_Integer pose = posrelat(luaL_optinteger(L, 3, posi), l);
+  int n, i;
+  if (posi < 1) posi = 1;
+  if (pose > (lua_Integer)l) pose = l;
+  if (posi > pose) return 0;  /* empty interval; return no values */
+  if (pose - posi >= INT_MAX)  /* arithmetic overflow? */
+    return luaL_error(L, "string slice too long");
+  n = (int)(pose -  posi) + 1;
+  luaL_checkstack(L, n, "string slice too long");
+  for (i=0; i<n; i++)
+    lua_pushinteger(L, uchar(s[posi+i-1]));
+  return n;
+}
+
+
+static int str_char (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  int i;
+  luaL_Buffer b;
+  char *p = luaL_buffinitsize(L, &b, n);
+  for (i=1; i<=n; i++) {
+    lua_Integer c = luaL_checkinteger(L, i);
+    luaL_argcheck(L, uchar(c) == c, i, "value out of range");
+    p[i - 1] = uchar(c);
+  }
+  luaL_pushresultsize(&b, n);
+  return 1;
+}
+
+
+static int writer (lua_State *L, const void *b, size_t size, void *B) {
+  (void)L;
+  luaL_addlstring((luaL_Buffer *) B, (const char *)b, size);
+  return 0;
+}
+
+
+static int str_dump (lua_State *L) {
+  luaL_Buffer b;
+  int strip = lua_toboolean(L, 2);
+  luaL_checktype(L, 1, LUA_TFUNCTION);
+  lua_settop(L, 1);
+  luaL_buffinit(L,&b);
+  if (lua_dump(L, writer, &b, strip) != 0)
+    return luaL_error(L, "unable to dump given function");
+  luaL_pushresult(&b);
+  return 1;
+}
+
+
+
+/*
+** {======================================================
+** PATTERN MATCHING
+** =======================================================
+*/
+
+
+#define CAP_UNFINISHED	(-1)
+#define CAP_POSITION	(-2)
+
+
+typedef struct MatchState {
+  const char *src_init;  /* init of source string */
+  const char *src_end;  /* end ('\0') of source string */
+  const char *p_end;  /* end ('\0') of pattern */
+  lua_State *L;
+  int matchdepth;  /* control for recursive depth (to avoid C stack overflow) */
+  unsigned char level;  /* total number of captures (finished or unfinished) */
+  struct {
+    const char *init;
+    ptrdiff_t len;
+  } capture[LUA_MAXCAPTURES];
+} MatchState;
+
+
+/* recursive function */
+static const char *match (MatchState *ms, const char *s, const char *p);
+
+
+/* maximum recursion depth for 'match' */
+#if !defined(MAXCCALLS)
+#define MAXCCALLS	200
+#endif
+
+
+#define L_ESC		'%'
+#define SPECIALS	"^$*+?.([%-"
+
+
+static int check_capture (MatchState *ms, int l) {
+  l -= '1';
+  if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
+    return luaL_error(ms->L, "invalid capture index %%%d", l + 1);
+  return l;
+}
+
+
+static int capture_to_close (MatchState *ms) {
+  int level = ms->level;
+  for (level--; level>=0; level--)
+    if (ms->capture[level].len == CAP_UNFINISHED) return level;
+  return luaL_error(ms->L, "invalid pattern capture");
+}
+
+
+static const char *classend (MatchState *ms, const char *p) {
+  switch (*p++) {
+    case L_ESC: {
+      if (p == ms->p_end)
+        luaL_error(ms->L, "malformed pattern (ends with '%%')");
+      return p+1;
+    }
+    case '[': {
+      if (*p == '^') p++;
+      do {  /* look for a ']' */
+        if (p == ms->p_end)
+          luaL_error(ms->L, "malformed pattern (missing ']')");
+        if (*(p++) == L_ESC && p < ms->p_end)
+          p++;  /* skip escapes (e.g. '%]') */
+      } while (*p != ']');
+      return p+1;
+    }
+    default: {
+      return p;
+    }
+  }
+}
+
+
+static int match_class (int c, int cl) {
+  int res;
+  switch (tolower(cl)) {
+    case 'a' : res = isalpha(c); break;
+    case 'c' : res = iscntrl(c); break;
+    case 'd' : res = isdigit(c); break;
+    case 'g' : res = isgraph(c); break;
+    case 'l' : res = islower(c); break;
+    case 'p' : res = ispunct(c); break;
+    case 's' : res = isspace(c); break;
+    case 'u' : res = isupper(c); break;
+    case 'w' : res = isalnum(c); break;
+    case 'x' : res = isxdigit(c); break;
+    case 'z' : res = (c == 0); break;  /* deprecated option */
+    default: return (cl == c);
+  }
+  return (islower(cl) ? res : !res);
+}
+
+
+static int matchbracketclass (int c, const char *p, const char *ec) {
+  int sig = 1;
+  if (*(p+1) == '^') {
+    sig = 0;
+    p++;  /* skip the '^' */
+  }
+  while (++p < ec) {
+    if (*p == L_ESC) {
+      p++;
+      if (match_class(c, uchar(*p)))
+        return sig;
+    }
+    else if ((*(p+1) == '-') && (p+2 < ec)) {
+      p+=2;
+      if (uchar(*(p-2)) <= c && c <= uchar(*p))
+        return sig;
+    }
+    else if (uchar(*p) == c) return sig;
+  }
+  return !sig;
+}
+
+
+static int singlematch (MatchState *ms, const char *s, const char *p,
+                        const char *ep) {
+  if (s >= ms->src_end)
+    return 0;
+  else {
+    int c = uchar(*s);
+    switch (*p) {
+      case '.': return 1;  /* matches any char */
+      case L_ESC: return match_class(c, uchar(*(p+1)));
+      case '[': return matchbracketclass(c, p, ep-1);
+      default:  return (uchar(*p) == c);
+    }
+  }
+}
+
+
+static const char *matchbalance (MatchState *ms, const char *s,
+                                   const char *p) {
+  if (p >= ms->p_end - 1)
+    luaL_error(ms->L, "malformed pattern (missing arguments to '%%b')");
+  if (*s != *p) return NULL;
+  else {
+    int b = *p;
+    int e = *(p+1);
+    int cont = 1;
+    while (++s < ms->src_end) {
+      if (*s == e) {
+        if (--cont == 0) return s+1;
+      }
+      else if (*s == b) cont++;
+    }
+  }
+  return NULL;  /* string ends out of balance */
+}
+
+
+static const char *max_expand (MatchState *ms, const char *s,
+                                 const char *p, const char *ep) {
+  ptrdiff_t i = 0;  /* counts maximum expand for item */
+  while (singlematch(ms, s + i, p, ep))
+    i++;
+  /* keeps trying to match with the maximum repetitions */
+  while (i>=0) {
+    const char *res = match(ms, (s+i), ep+1);
+    if (res) return res;
+    i--;  /* else didn't match; reduce 1 repetition to try again */
+  }
+  return NULL;
+}
+
+
+static const char *min_expand (MatchState *ms, const char *s,
+                                 const char *p, const char *ep) {
+  for (;;) {
+    const char *res = match(ms, s, ep+1);
+    if (res != NULL)
+      return res;
+    else if (singlematch(ms, s, p, ep))
+      s++;  /* try with one more repetition */
+    else return NULL;
+  }
+}
+
+
+static const char *start_capture (MatchState *ms, const char *s,
+                                    const char *p, int what) {
+  const char *res;
+  int level = ms->level;
+  if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures");
+  ms->capture[level].init = s;
+  ms->capture[level].len = what;
+  ms->level = level+1;
+  if ((res=match(ms, s, p)) == NULL)  /* match failed? */
+    ms->level--;  /* undo capture */
+  return res;
+}
+
+
+static const char *end_capture (MatchState *ms, const char *s,
+                                  const char *p) {
+  int l = capture_to_close(ms);
+  const char *res;
+  ms->capture[l].len = s - ms->capture[l].init;  /* close capture */
+  if ((res = match(ms, s, p)) == NULL)  /* match failed? */
+    ms->capture[l].len = CAP_UNFINISHED;  /* undo capture */
+  return res;
+}
+
+
+static const char *match_capture (MatchState *ms, const char *s, int l) {
+  size_t len;
+  l = check_capture(ms, l);
+  len = ms->capture[l].len;
+  if ((size_t)(ms->src_end-s) >= len &&
+      memcmp(ms->capture[l].init, s, len) == 0)
+    return s+len;
+  else return NULL;
+}
+
+
+static const char *match (MatchState *ms, const char *s, const char *p) {
+  if (ms->matchdepth-- == 0)
+    luaL_error(ms->L, "pattern too complex");
+  init: /* using goto's to optimize tail recursion */
+  if (p != ms->p_end) {  /* end of pattern? */
+    switch (*p) {
+      case '(': {  /* start capture */
+        if (*(p + 1) == ')')  /* position capture? */
+          s = start_capture(ms, s, p + 2, CAP_POSITION);
+        else
+          s = start_capture(ms, s, p + 1, CAP_UNFINISHED);
+        break;
+      }
+      case ')': {  /* end capture */
+        s = end_capture(ms, s, p + 1);
+        break;
+      }
+      case '$': {
+        if ((p + 1) != ms->p_end)  /* is the '$' the last char in pattern? */
+          goto dflt;  /* no; go to default */
+        s = (s == ms->src_end) ? s : NULL;  /* check end of string */
+        break;
+      }
+      case L_ESC: {  /* escaped sequences not in the format class[*+?-]? */
+        switch (*(p + 1)) {
+          case 'b': {  /* balanced string? */
+            s = matchbalance(ms, s, p + 2);
+            if (s != NULL) {
+              p += 4; goto init;  /* return match(ms, s, p + 4); */
+            }  /* else fail (s == NULL) */
+            break;
+          }
+          case 'f': {  /* frontier? */
+            const char *ep; char previous;
+            p += 2;
+            if (*p != '[')
+              luaL_error(ms->L, "missing '[' after '%%f' in pattern");
+            ep = classend(ms, p);  /* points to what is next */
+            previous = (s == ms->src_init) ? '\0' : *(s - 1);
+            if (!matchbracketclass(uchar(previous), p, ep - 1) &&
+               matchbracketclass(uchar(*s), p, ep - 1)) {
+              p = ep; goto init;  /* return match(ms, s, ep); */
+            }
+            s = NULL;  /* match failed */
+            break;
+          }
+          case '0': case '1': case '2': case '3':
+          case '4': case '5': case '6': case '7':
+          case '8': case '9': {  /* capture results (%0-%9)? */
+            s = match_capture(ms, s, uchar(*(p + 1)));
+            if (s != NULL) {
+              p += 2; goto init;  /* return match(ms, s, p + 2) */
+            }
+            break;
+          }
+          default: goto dflt;
+        }
+        break;
+      }
+      default: dflt: {  /* pattern class plus optional suffix */
+        const char *ep = classend(ms, p);  /* points to optional suffix */
+        /* does not match at least once? */
+        if (!singlematch(ms, s, p, ep)) {
+          if (*ep == '*' || *ep == '?' || *ep == '-') {  /* accept empty? */
+            p = ep + 1; goto init;  /* return match(ms, s, ep + 1); */
+          }
+          else  /* '+' or no suffix */
+            s = NULL;  /* fail */
+        }
+        else {  /* matched once */
+          switch (*ep) {  /* handle optional suffix */
+            case '?': {  /* optional */
+              const char *res;
+              if ((res = match(ms, s + 1, ep + 1)) != NULL)
+                s = res;
+              else {
+                p = ep + 1; goto init;  /* else return match(ms, s, ep + 1); */
+              }
+              break;
+            }
+            case '+':  /* 1 or more repetitions */
+              s++;  /* 1 match already done */
+              /* FALLTHROUGH */
+            case '*':  /* 0 or more repetitions */
+              s = max_expand(ms, s, p, ep);
+              break;
+            case '-':  /* 0 or more repetitions (minimum) */
+              s = min_expand(ms, s, p, ep);
+              break;
+            default:  /* no suffix */
+              s++; p = ep; goto init;  /* return match(ms, s + 1, ep); */
+          }
+        }
+        break;
+      }
+    }
+  }
+  ms->matchdepth++;
+  return s;
+}
+
+
+
+static const char *lmemfind (const char *s1, size_t l1,
+                               const char *s2, size_t l2) {
+  if (l2 == 0) return s1;  /* empty strings are everywhere */
+  else if (l2 > l1) return NULL;  /* avoids a negative 'l1' */
+  else {
+    const char *init;  /* to search for a '*s2' inside 's1' */
+    l2--;  /* 1st char will be checked by 'memchr' */
+    l1 = l1-l2;  /* 's2' cannot be found after that */
+    while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) {
+      init++;   /* 1st char is already checked */
+      if (memcmp(init, s2+1, l2) == 0)
+        return init-1;
+      else {  /* correct 'l1' and 's1' to try again */
+        l1 -= init-s1;
+        s1 = init;
+      }
+    }
+    return NULL;  /* not found */
+  }
+}
+
+
+static void push_onecapture (MatchState *ms, int i, const char *s,
+                                                    const char *e) {
+  if (i >= ms->level) {
+    if (i == 0)  /* ms->level == 0, too */
+      lua_pushlstring(ms->L, s, e - s);  /* add whole match */
+    else
+      luaL_error(ms->L, "invalid capture index %%%d", i + 1);
+  }
+  else {
+    ptrdiff_t l = ms->capture[i].len;
+    if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");
+    if (l == CAP_POSITION)
+      lua_pushinteger(ms->L, (ms->capture[i].init - ms->src_init) + 1);
+    else
+      lua_pushlstring(ms->L, ms->capture[i].init, l);
+  }
+}
+
+
+static int push_captures (MatchState *ms, const char *s, const char *e) {
+  int i;
+  int nlevels = (ms->level == 0 && s) ? 1 : ms->level;
+  luaL_checkstack(ms->L, nlevels, "too many captures");
+  for (i = 0; i < nlevels; i++)
+    push_onecapture(ms, i, s, e);
+  return nlevels;  /* number of strings pushed */
+}
+
+
+/* check whether pattern has no special characters */
+static int nospecials (const char *p, size_t l) {
+  size_t upto = 0;
+  do {
+    if (strpbrk(p + upto, SPECIALS))
+      return 0;  /* pattern has a special character */
+    upto += strlen(p + upto) + 1;  /* may have more after \0 */
+  } while (upto <= l);
+  return 1;  /* no special chars found */
+}
+
+
+static void prepstate (MatchState *ms, lua_State *L,
+                       const char *s, size_t ls, const char *p, size_t lp) {
+  ms->L = L;
+  ms->matchdepth = MAXCCALLS;
+  ms->src_init = s;
+  ms->src_end = s + ls;
+  ms->p_end = p + lp;
+}
+
+
+static void reprepstate (MatchState *ms) {
+  ms->level = 0;
+  lua_assert(ms->matchdepth == MAXCCALLS);
+}
+
+
+static int str_find_aux (lua_State *L, int find) {
+  size_t ls, lp;
+  const char *s = luaL_checklstring(L, 1, &ls);
+  const char *p = luaL_checklstring(L, 2, &lp);
+  lua_Integer init = posrelat(luaL_optinteger(L, 3, 1), ls);
+  if (init < 1) init = 1;
+  else if (init > (lua_Integer)ls + 1) {  /* start after string's end? */
+    lua_pushnil(L);  /* cannot find anything */
+    return 1;
+  }
+  /* explicit request or no special characters? */
+  if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) {
+    /* do a plain search */
+    const char *s2 = lmemfind(s + init - 1, ls - (size_t)init + 1, p, lp);
+    if (s2) {
+      lua_pushinteger(L, (s2 - s) + 1);
+      lua_pushinteger(L, (s2 - s) + lp);
+      return 2;
+    }
+  }
+  else {
+    MatchState ms;
+    const char *s1 = s + init - 1;
+    int anchor = (*p == '^');
+    if (anchor) {
+      p++; lp--;  /* skip anchor character */
+    }
+    prepstate(&ms, L, s, ls, p, lp);
+    do {
+      const char *res;
+      reprepstate(&ms);
+      if ((res=match(&ms, s1, p)) != NULL) {
+        if (find) {
+          lua_pushinteger(L, (s1 - s) + 1);  /* start */
+          lua_pushinteger(L, res - s);   /* end */
+          return push_captures(&ms, NULL, 0) + 2;
+        }
+        else
+          return push_captures(&ms, s1, res);
+      }
+    } while (s1++ < ms.src_end && !anchor);
+  }
+  lua_pushnil(L);  /* not found */
+  return 1;
+}
+
+
+static int str_find (lua_State *L) {
+  return str_find_aux(L, 1);
+}
+
+
+static int str_match (lua_State *L) {
+  return str_find_aux(L, 0);
+}
+
+
+/* state for 'gmatch' */
+typedef struct GMatchState {
+  const char *src;  /* current position */
+  const char *p;  /* pattern */
+  const char *lastmatch;  /* end of last match */
+  MatchState ms;  /* match state */
+} GMatchState;
+
+
+static int gmatch_aux (lua_State *L) {
+  GMatchState *gm = (GMatchState *)lua_touserdata(L, lua_upvalueindex(3));
+  const char *src;
+  gm->ms.L = L;
+  for (src = gm->src; src <= gm->ms.src_end; src++) {
+    const char *e;
+    reprepstate(&gm->ms);
+    if ((e = match(&gm->ms, src, gm->p)) != NULL && e != gm->lastmatch) {
+      gm->src = gm->lastmatch = e;
+      return push_captures(&gm->ms, src, e);
+    }
+  }
+  return 0;  /* not found */
+}
+
+
+static int gmatch (lua_State *L) {
+  size_t ls, lp;
+  const char *s = luaL_checklstring(L, 1, &ls);
+  const char *p = luaL_checklstring(L, 2, &lp);
+  GMatchState *gm;
+  lua_settop(L, 2);  /* keep them on closure to avoid being collected */
+  gm = (GMatchState *)lua_newuserdata(L, sizeof(GMatchState));
+  prepstate(&gm->ms, L, s, ls, p, lp);
+  gm->src = s; gm->p = p; gm->lastmatch = NULL;
+  lua_pushcclosure(L, gmatch_aux, 3);
+  return 1;
+}
+
+
+static void add_s (MatchState *ms, luaL_Buffer *b, const char *s,
+                                                   const char *e) {
+  size_t l, i;
+  lua_State *L = ms->L;
+  const char *news = lua_tolstring(L, 3, &l);
+  for (i = 0; i < l; i++) {
+    if (news[i] != L_ESC)
+      luaL_addchar(b, news[i]);
+    else {
+      i++;  /* skip ESC */
+      if (!isdigit(uchar(news[i]))) {
+        if (news[i] != L_ESC)
+          luaL_error(L, "invalid use of '%c' in replacement string", L_ESC);
+        luaL_addchar(b, news[i]);
+      }
+      else if (news[i] == '0')
+          luaL_addlstring(b, s, e - s);
+      else {
+        push_onecapture(ms, news[i] - '1', s, e);
+        luaL_tolstring(L, -1, NULL);  /* if number, convert it to string */
+        lua_remove(L, -2);  /* remove original value */
+        luaL_addvalue(b);  /* add capture to accumulated result */
+      }
+    }
+  }
+}
+
+
+static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
+                                       const char *e, int tr) {
+  lua_State *L = ms->L;
+  switch (tr) {
+    case LUA_TFUNCTION: {
+      int n;
+      lua_pushvalue(L, 3);
+      n = push_captures(ms, s, e);
+      lua_call(L, n, 1);
+      break;
+    }
+    case LUA_TTABLE: {
+      push_onecapture(ms, 0, s, e);
+      lua_gettable(L, 3);
+      break;
+    }
+    default: {  /* LUA_TNUMBER or LUA_TSTRING */
+      add_s(ms, b, s, e);
+      return;
+    }
+  }
+  if (!lua_toboolean(L, -1)) {  /* nil or false? */
+    lua_pop(L, 1);
+    lua_pushlstring(L, s, e - s);  /* keep original text */
+  }
+  else if (!lua_isstring(L, -1))
+    luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1));
+  luaL_addvalue(b);  /* add result to accumulator */
+}
+
+
+static int str_gsub (lua_State *L) {
+  size_t srcl, lp;
+  const char *src = luaL_checklstring(L, 1, &srcl);  /* subject */
+  const char *p = luaL_checklstring(L, 2, &lp);  /* pattern */
+  const char *lastmatch = NULL;  /* end of last match */
+  int tr = lua_type(L, 3);  /* replacement type */
+  lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1);  /* max replacements */
+  int anchor = (*p == '^');
+  lua_Integer n = 0;  /* replacement count */
+  MatchState ms;
+  luaL_Buffer b;
+  luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
+                   tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
+                      "string/function/table expected");
+  luaL_buffinit(L, &b);
+  if (anchor) {
+    p++; lp--;  /* skip anchor character */
+  }
+  prepstate(&ms, L, src, srcl, p, lp);
+  while (n < max_s) {
+    const char *e;
+    reprepstate(&ms);  /* (re)prepare state for new match */
+    if ((e = match(&ms, src, p)) != NULL && e != lastmatch) {  /* match? */
+      n++;
+      add_value(&ms, &b, src, e, tr);  /* add replacement to buffer */
+      src = lastmatch = e;
+    }
+    else if (src < ms.src_end)  /* otherwise, skip one character */
+      luaL_addchar(&b, *src++);
+    else break;  /* end of subject */
+    if (anchor) break;
+  }
+  luaL_addlstring(&b, src, ms.src_end-src);
+  luaL_pushresult(&b);
+  lua_pushinteger(L, n);  /* number of substitutions */
+  return 2;
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** STRING FORMAT
+** =======================================================
+*/
+
+#if !defined(lua_number2strx)	/* { */
+
+/*
+** Hexadecimal floating-point formatter
+*/
+
+#include <math.h>
+
+#define SIZELENMOD	(sizeof(LUA_NUMBER_FRMLEN)/sizeof(char))
+
+
+/*
+** Number of bits that goes into the first digit. It can be any value
+** between 1 and 4; the following definition tries to align the number
+** to nibble boundaries by making what is left after that first digit a
+** multiple of 4.
+*/
+#define L_NBFD		((l_mathlim(MANT_DIG) - 1)%4 + 1)
+
+
+/*
+** Add integer part of 'x' to buffer and return new 'x'
+*/
+static lua_Number adddigit (char *buff, int n, lua_Number x) {
+  lua_Number dd = l_mathop(floor)(x);  /* get integer part from 'x' */
+  int d = (int)dd;
+  buff[n] = (d < 10 ? d + '0' : d - 10 + 'a');  /* add to buffer */
+  return x - dd;  /* return what is left */
+}
+
+
+static int num2straux (char *buff, int sz, lua_Number x) {
+  if (x != x || x == HUGE_VAL || x == -HUGE_VAL)  /* inf or NaN? */
+    return l_sprintf(buff, sz, LUA_NUMBER_FMT, x);  /* equal to '%g' */
+  else if (x == 0) {  /* can be -0... */
+    /* create "0" or "-0" followed by exponent */
+    return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", x);
+  }
+  else {
+    int e;
+    lua_Number m = l_mathop(frexp)(x, &e);  /* 'x' fraction and exponent */
+    int n = 0;  /* character count */
+    if (m < 0) {  /* is number negative? */
+      buff[n++] = '-';  /* add signal */
+      m = -m;  /* make it positive */
+    }
+    buff[n++] = '0'; buff[n++] = 'x';  /* add "0x" */
+    m = adddigit(buff, n++, m * (1 << L_NBFD));  /* add first digit */
+    e -= L_NBFD;  /* this digit goes before the radix point */
+    if (m > 0) {  /* more digits? */
+      buff[n++] = lua_getlocaledecpoint();  /* add radix point */
+      do {  /* add as many digits as needed */
+        m = adddigit(buff, n++, m * 16);
+      } while (m > 0);
+    }
+    n += l_sprintf(buff + n, sz - n, "p%+d", e);  /* add exponent */
+    lua_assert(n < sz);
+    return n;
+  }
+}
+
+
+static int lua_number2strx (lua_State *L, char *buff, int sz,
+                            const char *fmt, lua_Number x) {
+  int n = num2straux(buff, sz, x);
+  if (fmt[SIZELENMOD] == 'A') {
+    int i;
+    for (i = 0; i < n; i++)
+      buff[i] = toupper(uchar(buff[i]));
+  }
+  else if (fmt[SIZELENMOD] != 'a')
+    luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented");
+  return n;
+}
+
+#endif				/* } */
+
+
+/*
+** Maximum size of each formatted item. This maximum size is produced
+** by format('%.99f', -maxfloat), and is equal to 99 + 3 ('-', '.',
+** and '\0') + number of decimal digits to represent maxfloat (which
+** is maximum exponent + 1). (99+3+1 then rounded to 120 for "extra
+** expenses", such as locale-dependent stuff)
+*/
+#define MAX_ITEM        (120 + l_mathlim(MAX_10_EXP))
+
+
+/* valid flags in a format specification */
+#define FLAGS	"-+ #0"
+
+/*
+** maximum size of each format specification (such as "%-099.99d")
+*/
+#define MAX_FORMAT	32
+
+
+static void addquoted (luaL_Buffer *b, const char *s, size_t len) {
+  luaL_addchar(b, '"');
+  while (len--) {
+    if (*s == '"' || *s == '\\' || *s == '\n') {
+      luaL_addchar(b, '\\');
+      luaL_addchar(b, *s);
+    }
+    else if (iscntrl(uchar(*s))) {
+      char buff[10];
+      if (!isdigit(uchar(*(s+1))))
+        l_sprintf(buff, sizeof(buff), "\\%d", (int)uchar(*s));
+      else
+        l_sprintf(buff, sizeof(buff), "\\%03d", (int)uchar(*s));
+      luaL_addstring(b, buff);
+    }
+    else
+      luaL_addchar(b, *s);
+    s++;
+  }
+  luaL_addchar(b, '"');
+}
+
+
+/*
+** Ensures the 'buff' string uses a dot as the radix character.
+*/
+static void checkdp (char *buff, int nb) {
+  if (memchr(buff, '.', nb) == NULL) {  /* no dot? */
+    char point = lua_getlocaledecpoint();  /* try locale point */
+    char *ppoint = memchr(buff, point, nb);
+    if (ppoint) *ppoint = '.';  /* change it to a dot */
+  }
+}
+
+
+static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
+  switch (lua_type(L, arg)) {
+    case LUA_TSTRING: {
+      size_t len;
+      const char *s = lua_tolstring(L, arg, &len);
+      addquoted(b, s, len);
+      break;
+    }
+    case LUA_TNUMBER: {
+      char *buff = luaL_prepbuffsize(b, MAX_ITEM);
+      int nb;
+      if (!lua_isinteger(L, arg)) {  /* float? */
+        lua_Number n = lua_tonumber(L, arg);  /* write as hexa ('%a') */
+        nb = lua_number2strx(L, buff, MAX_ITEM, "%" LUA_NUMBER_FRMLEN "a", n);
+        checkdp(buff, nb);  /* ensure it uses a dot */
+      }
+      else {  /* integers */
+        lua_Integer n = lua_tointeger(L, arg);
+        const char *format = (n == LUA_MININTEGER)  /* corner case? */
+                           ? "0x%" LUA_INTEGER_FRMLEN "x"  /* use hexa */
+                           : LUA_INTEGER_FMT;  /* else use default format */
+        nb = l_sprintf(buff, MAX_ITEM, format, n);
+      }
+      luaL_addsize(b, nb);
+      break;
+    }
+    case LUA_TNIL: case LUA_TBOOLEAN: {
+      luaL_tolstring(L, arg, NULL);
+      luaL_addvalue(b);
+      break;
+    }
+    default: {
+      luaL_argerror(L, arg, "value has no literal form");
+    }
+  }
+}
+
+
+static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
+  const char *p = strfrmt;
+  while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++;  /* skip flags */
+  if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char))
+    luaL_error(L, "invalid format (repeated flags)");
+  if (isdigit(uchar(*p))) p++;  /* skip width */
+  if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
+  if (*p == '.') {
+    p++;
+    if (isdigit(uchar(*p))) p++;  /* skip precision */
+    if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
+  }
+  if (isdigit(uchar(*p)))
+    luaL_error(L, "invalid format (width or precision too long)");
+  *(form++) = '%';
+  memcpy(form, strfrmt, ((p - strfrmt) + 1) * sizeof(char));
+  form += (p - strfrmt) + 1;
+  *form = '\0';
+  return p;
+}
+
+
+/*
+** add length modifier into formats
+*/
+static void addlenmod (char *form, const char *lenmod) {
+  size_t l = strlen(form);
+  size_t lm = strlen(lenmod);
+  char spec = form[l - 1];
+  strcpy(form + l - 1, lenmod);
+  form[l + lm - 1] = spec;
+  form[l + lm] = '\0';
+}
+
+
+static int str_format (lua_State *L) {
+  int top = lua_gettop(L);
+  int arg = 1;
+  size_t sfl;
+  const char *strfrmt = luaL_checklstring(L, arg, &sfl);
+  const char *strfrmt_end = strfrmt+sfl;
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  while (strfrmt < strfrmt_end) {
+    if (*strfrmt != L_ESC)
+      luaL_addchar(&b, *strfrmt++);
+    else if (*++strfrmt == L_ESC)
+      luaL_addchar(&b, *strfrmt++);  /* %% */
+    else { /* format item */
+      char form[MAX_FORMAT];  /* to store the format ('%...') */
+      char *buff = luaL_prepbuffsize(&b, MAX_ITEM);  /* to put formatted item */
+      int nb = 0;  /* number of bytes in added item */
+      if (++arg > top)
+        luaL_argerror(L, arg, "no value");
+      strfrmt = scanformat(L, strfrmt, form);
+      switch (*strfrmt++) {
+        case 'c': {
+          nb = l_sprintf(buff, MAX_ITEM, form, (int)luaL_checkinteger(L, arg));
+          break;
+        }
+        case 'd': case 'i':
+        case 'o': case 'u': case 'x': case 'X': {
+          lua_Integer n = luaL_checkinteger(L, arg);
+          addlenmod(form, LUA_INTEGER_FRMLEN);
+          nb = l_sprintf(buff, MAX_ITEM, form, n);
+          break;
+        }
+        case 'a': case 'A':
+          addlenmod(form, LUA_NUMBER_FRMLEN);
+          nb = lua_number2strx(L, buff, MAX_ITEM, form,
+                                  luaL_checknumber(L, arg));
+          break;
+        case 'e': case 'E': case 'f':
+        case 'g': case 'G': {
+          addlenmod(form, LUA_NUMBER_FRMLEN);
+          nb = l_sprintf(buff, MAX_ITEM, form, luaL_checknumber(L, arg));
+          break;
+        }
+        case 'q': {
+          addliteral(L, &b, arg);
+          break;
+        }
+        case 's': {
+          size_t l;
+          const char *s = luaL_tolstring(L, arg, &l);
+          if (form[2] == '\0')  /* no modifiers? */
+            luaL_addvalue(&b);  /* keep entire string */
+          else {
+            luaL_argcheck(L, l == strlen(s), arg, "string contains zeros");
+            if (!strchr(form, '.') && l >= 100) {
+              /* no precision and string is too long to be formatted */
+              luaL_addvalue(&b);  /* keep entire string */
+            }
+            else {  /* format the string into 'buff' */
+              nb = l_sprintf(buff, MAX_ITEM, form, s);
+              lua_pop(L, 1);  /* remove result from 'luaL_tolstring' */
+            }
+          }
+          break;
+        }
+        default: {  /* also treat cases 'pnLlh' */
+          return luaL_error(L, "invalid option '%%%c' to 'format'",
+                               *(strfrmt - 1));
+        }
+      }
+      lua_assert(nb < MAX_ITEM);
+      luaL_addsize(&b, nb);
+    }
+  }
+  luaL_pushresult(&b);
+  return 1;
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** PACK/UNPACK
+** =======================================================
+*/
+
+
+/* value used for padding */
+#if !defined(LUAL_PACKPADBYTE)
+#define LUAL_PACKPADBYTE		0x00
+#endif
+
+/* maximum size for the binary representation of an integer */
+#define MAXINTSIZE	16
+
+/* number of bits in a character */
+#define NB	CHAR_BIT
+
+/* mask for one character (NB 1's) */
+#define MC	((1 << NB) - 1)
+
+/* size of a lua_Integer */
+#define SZINT	((int)sizeof(lua_Integer))
+
+
+/* dummy union to get native endianness */
+static const union {
+  int dummy;
+  char little;  /* true iff machine is little endian */
+} nativeendian = {1};
+
+
+/* dummy structure to get native alignment requirements */
+struct cD {
+  char c;
+  union { double d; void *p; lua_Integer i; lua_Number n; } u;
+};
+
+#define MAXALIGN	(offsetof(struct cD, u))
+
+
+/*
+** Union for serializing floats
+*/
+typedef union Ftypes {
+  float f;
+  double d;
+  lua_Number n;
+  char buff[5 * sizeof(lua_Number)];  /* enough for any float type */
+} Ftypes;
+
+
+/*
+** information to pack/unpack stuff
+*/
+typedef struct Header {
+  lua_State *L;
+  int islittle;
+  int maxalign;
+} Header;
+
+
+/*
+** options for pack/unpack
+*/
+typedef enum KOption {
+  Kint,		/* signed integers */
+  Kuint,	/* unsigned integers */
+  Kfloat,	/* floating-point numbers */
+  Kchar,	/* fixed-length strings */
+  Kstring,	/* strings with prefixed length */
+  Kzstr,	/* zero-terminated strings */
+  Kpadding,	/* padding */
+  Kpaddalign,	/* padding for alignment */
+  Knop		/* no-op (configuration or spaces) */
+} KOption;
+
+
+/*
+** Read an integer numeral from string 'fmt' or return 'df' if
+** there is no numeral
+*/
+static int digit (int c) { return '0' <= c && c <= '9'; }
+
+static int getnum (const char **fmt, int df) {
+  if (!digit(**fmt))  /* no number? */
+    return df;  /* return default value */
+  else {
+    int a = 0;
+    do {
+      a = a*10 + (*((*fmt)++) - '0');
+    } while (digit(**fmt) && a <= ((int)MAXSIZE - 9)/10);
+    return a;
+  }
+}
+
+
+/*
+** Read an integer numeral and raises an error if it is larger
+** than the maximum size for integers.
+*/
+static int getnumlimit (Header *h, const char **fmt, int df) {
+  int sz = getnum(fmt, df);
+  if (sz > MAXINTSIZE || sz <= 0)
+    luaL_error(h->L, "integral size (%d) out of limits [1,%d]",
+                     sz, MAXINTSIZE);
+  return sz;
+}
+
+
+/*
+** Initialize Header
+*/
+static void initheader (lua_State *L, Header *h) {
+  h->L = L;
+  h->islittle = nativeendian.little;
+  h->maxalign = 1;
+}
+
+
+/*
+** Read and classify next option. 'size' is filled with option's size.
+*/
+static KOption getoption (Header *h, const char **fmt, int *size) {
+  int opt = *((*fmt)++);
+  *size = 0;  /* default */
+  switch (opt) {
+    case 'b': *size = sizeof(char); return Kint;
+    case 'B': *size = sizeof(char); return Kuint;
+    case 'h': *size = sizeof(short); return Kint;
+    case 'H': *size = sizeof(short); return Kuint;
+    case 'l': *size = sizeof(long); return Kint;
+    case 'L': *size = sizeof(long); return Kuint;
+    case 'j': *size = sizeof(lua_Integer); return Kint;
+    case 'J': *size = sizeof(lua_Integer); return Kuint;
+    case 'T': *size = sizeof(size_t); return Kuint;
+    case 'f': *size = sizeof(float); return Kfloat;
+    case 'd': *size = sizeof(double); return Kfloat;
+    case 'n': *size = sizeof(lua_Number); return Kfloat;
+    case 'i': *size = getnumlimit(h, fmt, sizeof(int)); return Kint;
+    case 'I': *size = getnumlimit(h, fmt, sizeof(int)); return Kuint;
+    case 's': *size = getnumlimit(h, fmt, sizeof(size_t)); return Kstring;
+    case 'c':
+      *size = getnum(fmt, -1);
+      if (*size == -1)
+        luaL_error(h->L, "missing size for format option 'c'");
+      return Kchar;
+    case 'z': return Kzstr;
+    case 'x': *size = 1; return Kpadding;
+    case 'X': return Kpaddalign;
+    case ' ': break;
+    case '<': h->islittle = 1; break;
+    case '>': h->islittle = 0; break;
+    case '=': h->islittle = nativeendian.little; break;
+    case '!': h->maxalign = getnumlimit(h, fmt, MAXALIGN); break;
+    default: luaL_error(h->L, "invalid format option '%c'", opt);
+  }
+  return Knop;
+}
+
+
+/*
+** Read, classify, and fill other details about the next option.
+** 'psize' is filled with option's size, 'notoalign' with its
+** alignment requirements.
+** Local variable 'size' gets the size to be aligned. (Kpadal option
+** always gets its full alignment, other options are limited by 
+** the maximum alignment ('maxalign'). Kchar option needs no alignment
+** despite its size.
+*/
+static KOption getdetails (Header *h, size_t totalsize,
+                           const char **fmt, int *psize, int *ntoalign) {
+  KOption opt = getoption(h, fmt, psize);
+  int align = *psize;  /* usually, alignment follows size */
+  if (opt == Kpaddalign) {  /* 'X' gets alignment from following option */
+    if (**fmt == '\0' || getoption(h, fmt, &align) == Kchar || align == 0)
+      luaL_argerror(h->L, 1, "invalid next option for option 'X'");
+  }
+  if (align <= 1 || opt == Kchar)  /* need no alignment? */
+    *ntoalign = 0;
+  else {
+    if (align > h->maxalign)  /* enforce maximum alignment */
+      align = h->maxalign;
+    if ((align & (align - 1)) != 0)  /* is 'align' not a power of 2? */
+      luaL_argerror(h->L, 1, "format asks for alignment not power of 2");
+    *ntoalign = (align - (int)(totalsize & (align - 1))) & (align - 1);
+  }
+  return opt;
+}
+
+
+/*
+** Pack integer 'n' with 'size' bytes and 'islittle' endianness.
+** The final 'if' handles the case when 'size' is larger than
+** the size of a Lua integer, correcting the extra sign-extension
+** bytes if necessary (by default they would be zeros).
+*/
+static void packint (luaL_Buffer *b, lua_Unsigned n,
+                     int islittle, int size, int neg) {
+  char *buff = luaL_prepbuffsize(b, size);
+  int i;
+  buff[islittle ? 0 : size - 1] = (char)(n & MC);  /* first byte */
+  for (i = 1; i < size; i++) {
+    n >>= NB;
+    buff[islittle ? i : size - 1 - i] = (char)(n & MC);
+  }
+  if (neg && size > SZINT) {  /* negative number need sign extension? */
+    for (i = SZINT; i < size; i++)  /* correct extra bytes */
+      buff[islittle ? i : size - 1 - i] = (char)MC;
+  }
+  luaL_addsize(b, size);  /* add result to buffer */
+}
+
+
+/*
+** Copy 'size' bytes from 'src' to 'dest', correcting endianness if
+** given 'islittle' is different from native endianness.
+*/
+static void copywithendian (volatile char *dest, volatile const char *src,
+                            int size, int islittle) {
+  if (islittle == nativeendian.little) {
+    while (size-- != 0)
+      *(dest++) = *(src++);
+  }
+  else {
+    dest += size - 1;
+    while (size-- != 0)
+      *(dest--) = *(src++);
+  }
+}
+
+
+static int str_pack (lua_State *L) {
+  luaL_Buffer b;
+  Header h;
+  const char *fmt = luaL_checkstring(L, 1);  /* format string */
+  int arg = 1;  /* current argument to pack */
+  size_t totalsize = 0;  /* accumulate total size of result */
+  initheader(L, &h);
+  lua_pushnil(L);  /* mark to separate arguments from string buffer */
+  luaL_buffinit(L, &b);
+  while (*fmt != '\0') {
+    int size, ntoalign;
+    KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign);
+    totalsize += ntoalign + size;
+    while (ntoalign-- > 0)
+     luaL_addchar(&b, LUAL_PACKPADBYTE);  /* fill alignment */
+    arg++;
+    switch (opt) {
+      case Kint: {  /* signed integers */
+        lua_Integer n = luaL_checkinteger(L, arg);
+        if (size < SZINT) {  /* need overflow check? */
+          lua_Integer lim = (lua_Integer)1 << ((size * NB) - 1);
+          luaL_argcheck(L, -lim <= n && n < lim, arg, "integer overflow");
+        }
+        packint(&b, (lua_Unsigned)n, h.islittle, size, (n < 0));
+        break;
+      }
+      case Kuint: {  /* unsigned integers */
+        lua_Integer n = luaL_checkinteger(L, arg);
+        if (size < SZINT)  /* need overflow check? */
+          luaL_argcheck(L, (lua_Unsigned)n < ((lua_Unsigned)1 << (size * NB)),
+                           arg, "unsigned overflow");
+        packint(&b, (lua_Unsigned)n, h.islittle, size, 0);
+        break;
+      }
+      case Kfloat: {  /* floating-point options */
+        volatile Ftypes u;
+        char *buff = luaL_prepbuffsize(&b, size);
+        lua_Number n = luaL_checknumber(L, arg);  /* get argument */
+        if (size == sizeof(u.f)) u.f = (float)n;  /* copy it into 'u' */
+        else if (size == sizeof(u.d)) u.d = (double)n;
+        else u.n = n;
+        /* move 'u' to final result, correcting endianness if needed */
+        copywithendian(buff, u.buff, size, h.islittle);
+        luaL_addsize(&b, size);
+        break;
+      }
+      case Kchar: {  /* fixed-size string */
+        size_t len;
+        const char *s = luaL_checklstring(L, arg, &len);
+        luaL_argcheck(L, len <= (size_t)size, arg,
+                         "string longer than given size");
+        luaL_addlstring(&b, s, len);  /* add string */
+        while (len++ < (size_t)size)  /* pad extra space */
+          luaL_addchar(&b, LUAL_PACKPADBYTE);
+        break;
+      }
+      case Kstring: {  /* strings with length count */
+        size_t len;
+        const char *s = luaL_checklstring(L, arg, &len);
+        luaL_argcheck(L, size >= (int)sizeof(size_t) ||
+                         len < ((size_t)1 << (size * NB)),
+                         arg, "string length does not fit in given size");
+        packint(&b, (lua_Unsigned)len, h.islittle, size, 0);  /* pack length */
+        luaL_addlstring(&b, s, len);
+        totalsize += len;
+        break;
+      }
+      case Kzstr: {  /* zero-terminated string */
+        size_t len;
+        const char *s = luaL_checklstring(L, arg, &len);
+        luaL_argcheck(L, strlen(s) == len, arg, "string contains zeros");
+        luaL_addlstring(&b, s, len);
+        luaL_addchar(&b, '\0');  /* add zero at the end */
+        totalsize += len + 1;
+        break;
+      }
+      case Kpadding: luaL_addchar(&b, LUAL_PACKPADBYTE);  /* FALLTHROUGH */
+      case Kpaddalign: case Knop:
+        arg--;  /* undo increment */
+        break;
+    }
+  }
+  luaL_pushresult(&b);
+  return 1;
+}
+
+
+static int str_packsize (lua_State *L) {
+  Header h;
+  const char *fmt = luaL_checkstring(L, 1);  /* format string */
+  size_t totalsize = 0;  /* accumulate total size of result */
+  initheader(L, &h);
+  while (*fmt != '\0') {
+    int size, ntoalign;
+    KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign);
+    size += ntoalign;  /* total space used by option */
+    luaL_argcheck(L, totalsize <= MAXSIZE - size, 1,
+                     "format result too large");
+    totalsize += size;
+    switch (opt) {
+      case Kstring:  /* strings with length count */
+      case Kzstr:    /* zero-terminated string */
+        luaL_argerror(L, 1, "variable-length format");
+        /* call never return, but to avoid warnings: *//* FALLTHROUGH */
+      default:  break;
+    }
+  }
+  lua_pushinteger(L, (lua_Integer)totalsize);
+  return 1;
+}
+
+
+/*
+** Unpack an integer with 'size' bytes and 'islittle' endianness.
+** If size is smaller than the size of a Lua integer and integer
+** is signed, must do sign extension (propagating the sign to the
+** higher bits); if size is larger than the size of a Lua integer,
+** it must check the unread bytes to see whether they do not cause an
+** overflow.
+*/
+static lua_Integer unpackint (lua_State *L, const char *str,
+                              int islittle, int size, int issigned) {
+  lua_Unsigned res = 0;
+  int i;
+  int limit = (size  <= SZINT) ? size : SZINT;
+  for (i = limit - 1; i >= 0; i--) {
+    res <<= NB;
+    res |= (lua_Unsigned)(unsigned char)str[islittle ? i : size - 1 - i];
+  }
+  if (size < SZINT) {  /* real size smaller than lua_Integer? */
+    if (issigned) {  /* needs sign extension? */
+      lua_Unsigned mask = (lua_Unsigned)1 << (size*NB - 1);
+      res = ((res ^ mask) - mask);  /* do sign extension */
+    }
+  }
+  else if (size > SZINT) {  /* must check unread bytes */
+    int mask = (!issigned || (lua_Integer)res >= 0) ? 0 : MC;
+    for (i = limit; i < size; i++) {
+      if ((unsigned char)str[islittle ? i : size - 1 - i] != mask)
+        luaL_error(L, "%d-byte integer does not fit into Lua Integer", size);
+    }
+  }
+  return (lua_Integer)res;
+}
+
+
+static int str_unpack (lua_State *L) {
+  Header h;
+  const char *fmt = luaL_checkstring(L, 1);
+  size_t ld;
+  const char *data = luaL_checklstring(L, 2, &ld);
+  size_t pos = (size_t)posrelat(luaL_optinteger(L, 3, 1), ld) - 1;
+  int n = 0;  /* number of results */
+  luaL_argcheck(L, pos <= ld, 3, "initial position out of string");
+  initheader(L, &h);
+  while (*fmt != '\0') {
+    int size, ntoalign;
+    KOption opt = getdetails(&h, pos, &fmt, &size, &ntoalign);
+    if ((size_t)ntoalign + size > ~pos || pos + ntoalign + size > ld)
+      luaL_argerror(L, 2, "data string too short");
+    pos += ntoalign;  /* skip alignment */
+    /* stack space for item + next position */
+    luaL_checkstack(L, 2, "too many results");
+    n++;
+    switch (opt) {
+      case Kint:
+      case Kuint: {
+        lua_Integer res = unpackint(L, data + pos, h.islittle, size,
+                                       (opt == Kint));
+        lua_pushinteger(L, res);
+        break;
+      }
+      case Kfloat: {
+        volatile Ftypes u;
+        lua_Number num;
+        copywithendian(u.buff, data + pos, size, h.islittle);
+        if (size == sizeof(u.f)) num = (lua_Number)u.f;
+        else if (size == sizeof(u.d)) num = (lua_Number)u.d;
+        else num = u.n;
+        lua_pushnumber(L, num);
+        break;
+      }
+      case Kchar: {
+        lua_pushlstring(L, data + pos, size);
+        break;
+      }
+      case Kstring: {
+        size_t len = (size_t)unpackint(L, data + pos, h.islittle, size, 0);
+        luaL_argcheck(L, pos + len + size <= ld, 2, "data string too short");
+        lua_pushlstring(L, data + pos + size, len);
+        pos += len;  /* skip string */
+        break;
+      }
+      case Kzstr: {
+        size_t len = (int)strlen(data + pos);
+        lua_pushlstring(L, data + pos, len);
+        pos += len + 1;  /* skip string plus final '\0' */
+        break;
+      }
+      case Kpaddalign: case Kpadding: case Knop:
+        n--;  /* undo increment */
+        break;
+    }
+    pos += size;
+  }
+  lua_pushinteger(L, pos + 1);  /* next position */
+  return n + 1;
+}
+
+/* }====================================================== */
+
+
+static const luaL_Reg strlib[] = {
+  {"byte", str_byte},
+  {"char", str_char},
+  {"dump", str_dump},
+  {"find", str_find},
+  {"format", str_format},
+  {"gmatch", gmatch},
+  {"gsub", str_gsub},
+  {"len", str_len},
+  {"lower", str_lower},
+  {"match", str_match},
+  {"rep", str_rep},
+  {"reverse", str_reverse},
+  {"sub", str_sub},
+  {"upper", str_upper},
+  {"pack", str_pack},
+  {"packsize", str_packsize},
+  {"unpack", str_unpack},
+  {NULL, NULL}
+};
+
+
+static void createmetatable (lua_State *L) {
+  lua_createtable(L, 0, 1);  /* table to be metatable for strings */
+  lua_pushliteral(L, "");  /* dummy string */
+  lua_pushvalue(L, -2);  /* copy table */
+  lua_setmetatable(L, -2);  /* set table as metatable for strings */
+  lua_pop(L, 1);  /* pop dummy string */
+  lua_pushvalue(L, -2);  /* get string library */
+  lua_setfield(L, -2, "__index");  /* metatable.__index = string */
+  lua_pop(L, 1);  /* pop metatable */
+}
+
+
+/*
+** Open string library
+*/
+LUAMOD_API int luaopen_string (lua_State *L) {
+  luaL_newlib(L, strlib);
+  createmetatable(L);
+  return 1;
+}
+
diff --git a/src/ltable.c b/src/ltable.c
new file mode 100644
index 0000000..7e15b71
--- /dev/null
+++ b/src/ltable.c
@@ -0,0 +1,669 @@
+/*
+** $Id: ltable.c,v 2.117 2015/11/19 19:16:22 roberto Exp $
+** Lua tables (hash)
+** See Copyright Notice in lua.h
+*/
+
+#define ltable_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+/*
+** Implementation of tables (aka arrays, objects, or hash tables).
+** Tables keep its elements in two parts: an array part and a hash part.
+** Non-negative integer keys are all candidates to be kept in the array
+** part. The actual size of the array is the largest 'n' such that
+** more than half the slots between 1 and n are in use.
+** Hash uses a mix of chained scatter table with Brent's variation.
+** A main invariant of these tables is that, if an element is not
+** in its main position (i.e. the 'original' position that its hash gives
+** to it), then the colliding element is in its own main position.
+** Hence even when the load factor reaches 100%, performance remains good.
+*/
+
+#include <math.h>
+#include <limits.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "lvm.h"
+
+
+/*
+** Maximum size of array part (MAXASIZE) is 2^MAXABITS. MAXABITS is
+** the largest integer such that MAXASIZE fits in an unsigned int.
+*/
+#define MAXABITS	cast_int(sizeof(int) * CHAR_BIT - 1)
+#define MAXASIZE	(1u << MAXABITS)
+
+/*
+** Maximum size of hash part is 2^MAXHBITS. MAXHBITS is the largest
+** integer such that 2^MAXHBITS fits in a signed int. (Note that the
+** maximum number of elements in a table, 2^MAXABITS + 2^MAXHBITS, still
+** fits comfortably in an unsigned int.)
+*/
+#define MAXHBITS	(MAXABITS - 1)
+
+
+#define hashpow2(t,n)		(gnode(t, lmod((n), sizenode(t))))
+
+#define hashstr(t,str)		hashpow2(t, (str)->hash)
+#define hashboolean(t,p)	hashpow2(t, p)
+#define hashint(t,i)		hashpow2(t, i)
+
+
+/*
+** for some types, it is better to avoid modulus by power of 2, as
+** they tend to have many 2 factors.
+*/
+#define hashmod(t,n)	(gnode(t, ((n) % ((sizenode(t)-1)|1))))
+
+
+#define hashpointer(t,p)	hashmod(t, point2uint(p))
+
+
+#define dummynode		(&dummynode_)
+
+#define isdummy(n)		((n) == dummynode)
+
+static const Node dummynode_ = {
+  {NILCONSTANT},  /* value */
+  {{NILCONSTANT, 0}}  /* key */
+};
+
+
+/*
+** Hash for floating-point numbers.
+** The main computation should be just
+**     n = frexp(n, &i); return (n * INT_MAX) + i
+** but there are some numerical subtleties.
+** In a two-complement representation, INT_MAX does not has an exact
+** representation as a float, but INT_MIN does; because the absolute
+** value of 'frexp' is smaller than 1 (unless 'n' is inf/NaN), the
+** absolute value of the product 'frexp * -INT_MIN' is smaller or equal
+** to INT_MAX. Next, the use of 'unsigned int' avoids overflows when
+** adding 'i'; the use of '~u' (instead of '-u') avoids problems with
+** INT_MIN.
+*/
+#if !defined(l_hashfloat)
+static int l_hashfloat (lua_Number n) {
+  int i;
+  lua_Integer ni;
+  n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN);
+  if (!lua_numbertointeger(n, &ni)) {  /* is 'n' inf/-inf/NaN? */
+    lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL));
+    return 0;
+  }
+  else {  /* normal case */
+    unsigned int u = cast(unsigned int, i) + cast(unsigned int, ni);
+    return cast_int(u <= cast(unsigned int, INT_MAX) ? u : ~u);
+  }
+}
+#endif
+
+
+/*
+** returns the 'main' position of an element in a table (that is, the index
+** of its hash value)
+*/
+static Node *mainposition (const Table *t, const TValue *key) {
+  switch (ttype(key)) {
+    case LUA_TNUMINT:
+      return hashint(t, ivalue(key));
+    case LUA_TNUMFLT:
+      return hashmod(t, l_hashfloat(fltvalue(key)));
+    case LUA_TSHRSTR:
+      return hashstr(t, tsvalue(key));
+    case LUA_TLNGSTR:
+      return hashpow2(t, luaS_hashlongstr(tsvalue(key)));
+    case LUA_TBOOLEAN:
+      return hashboolean(t, bvalue(key));
+    case LUA_TLIGHTUSERDATA:
+      return hashpointer(t, pvalue(key));
+    case LUA_TLCF:
+      return hashpointer(t, fvalue(key));
+    default:
+      lua_assert(!ttisdeadkey(key));
+      return hashpointer(t, gcvalue(key));
+  }
+}
+
+
+/*
+** returns the index for 'key' if 'key' is an appropriate key to live in
+** the array part of the table, 0 otherwise.
+*/
+static unsigned int arrayindex (const TValue *key) {
+  if (ttisinteger(key)) {
+    lua_Integer k = ivalue(key);
+    if (0 < k && (lua_Unsigned)k <= MAXASIZE)
+      return cast(unsigned int, k);  /* 'key' is an appropriate array index */
+  }
+  return 0;  /* 'key' did not match some condition */
+}
+
+
+/*
+** returns the index of a 'key' for table traversals. First goes all
+** elements in the array part, then elements in the hash part. The
+** beginning of a traversal is signaled by 0.
+*/
+static unsigned int findindex (lua_State *L, Table *t, StkId key) {
+  unsigned int i;
+  if (ttisnil(key)) return 0;  /* first iteration */
+  i = arrayindex(key);
+  if (i != 0 && i <= t->sizearray)  /* is 'key' inside array part? */
+    return i;  /* yes; that's the index */
+  else {
+    int nx;
+    Node *n = mainposition(t, key);
+    for (;;) {  /* check whether 'key' is somewhere in the chain */
+      /* key may be dead already, but it is ok to use it in 'next' */
+      if (luaV_rawequalobj(gkey(n), key) ||
+            (ttisdeadkey(gkey(n)) && iscollectable(key) &&
+             deadvalue(gkey(n)) == gcvalue(key))) {
+        i = cast_int(n - gnode(t, 0));  /* key index in hash table */
+        /* hash elements are numbered after array ones */
+        return (i + 1) + t->sizearray;
+      }
+      nx = gnext(n);
+      if (nx == 0)
+        luaG_runerror(L, "invalid key to 'next'");  /* key not found */
+      else n += nx;
+    }
+  }
+}
+
+
+int luaH_next (lua_State *L, Table *t, StkId key) {
+  unsigned int i = findindex(L, t, key);  /* find original element */
+  for (; i < t->sizearray; i++) {  /* try first array part */
+    if (!ttisnil(&t->array[i])) {  /* a non-nil value? */
+      setivalue(key, i + 1);
+      setobj2s(L, key+1, &t->array[i]);
+      return 1;
+    }
+  }
+  for (i -= t->sizearray; cast_int(i) < sizenode(t); i++) {  /* hash part */
+    if (!ttisnil(gval(gnode(t, i)))) {  /* a non-nil value? */
+      setobj2s(L, key, gkey(gnode(t, i)));
+      setobj2s(L, key+1, gval(gnode(t, i)));
+      return 1;
+    }
+  }
+  return 0;  /* no more elements */
+}
+
+
+/*
+** {=============================================================
+** Rehash
+** ==============================================================
+*/
+
+/*
+** Compute the optimal size for the array part of table 't'. 'nums' is a
+** "count array" where 'nums[i]' is the number of integers in the table
+** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of
+** integer keys in the table and leaves with the number of keys that
+** will go to the array part; return the optimal size.
+*/
+static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
+  int i;
+  unsigned int twotoi;  /* 2^i (candidate for optimal size) */
+  unsigned int a = 0;  /* number of elements smaller than 2^i */
+  unsigned int na = 0;  /* number of elements to go to array part */
+  unsigned int optimal = 0;  /* optimal size for array part */
+  /* loop while keys can fill more than half of total size */
+  for (i = 0, twotoi = 1; *pna > twotoi / 2; i++, twotoi *= 2) {
+    if (nums[i] > 0) {
+      a += nums[i];
+      if (a > twotoi/2) {  /* more than half elements present? */
+        optimal = twotoi;  /* optimal size (till now) */
+        na = a;  /* all elements up to 'optimal' will go to array part */
+      }
+    }
+  }
+  lua_assert((optimal == 0 || optimal / 2 < na) && na <= optimal);
+  *pna = na;
+  return optimal;
+}
+
+
+static int countint (const TValue *key, unsigned int *nums) {
+  unsigned int k = arrayindex(key);
+  if (k != 0) {  /* is 'key' an appropriate array index? */
+    nums[luaO_ceillog2(k)]++;  /* count as such */
+    return 1;
+  }
+  else
+    return 0;
+}
+
+
+/*
+** Count keys in array part of table 't': Fill 'nums[i]' with
+** number of keys that will go into corresponding slice and return
+** total number of non-nil keys.
+*/
+static unsigned int numusearray (const Table *t, unsigned int *nums) {
+  int lg;
+  unsigned int ttlg;  /* 2^lg */
+  unsigned int ause = 0;  /* summation of 'nums' */
+  unsigned int i = 1;  /* count to traverse all array keys */
+  /* traverse each slice */
+  for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) {
+    unsigned int lc = 0;  /* counter */
+    unsigned int lim = ttlg;
+    if (lim > t->sizearray) {
+      lim = t->sizearray;  /* adjust upper limit */
+      if (i > lim)
+        break;  /* no more elements to count */
+    }
+    /* count elements in range (2^(lg - 1), 2^lg] */
+    for (; i <= lim; i++) {
+      if (!ttisnil(&t->array[i-1]))
+        lc++;
+    }
+    nums[lg] += lc;
+    ause += lc;
+  }
+  return ause;
+}
+
+
+static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) {
+  int totaluse = 0;  /* total number of elements */
+  int ause = 0;  /* elements added to 'nums' (can go to array part) */
+  int i = sizenode(t);
+  while (i--) {
+    Node *n = &t->node[i];
+    if (!ttisnil(gval(n))) {
+      ause += countint(gkey(n), nums);
+      totaluse++;
+    }
+  }
+  *pna += ause;
+  return totaluse;
+}
+
+
+static void setarrayvector (lua_State *L, Table *t, unsigned int size) {
+  unsigned int i;
+  luaM_reallocvector(L, t->array, t->sizearray, size, TValue);
+  for (i=t->sizearray; i<size; i++)
+     setnilvalue(&t->array[i]);
+  t->sizearray = size;
+}
+
+
+static void setnodevector (lua_State *L, Table *t, unsigned int size) {
+  int lsize;
+  if (size == 0) {  /* no elements to hash part? */
+    t->node = cast(Node *, dummynode);  /* use common 'dummynode' */
+    lsize = 0;
+  }
+  else {
+    int i;
+    lsize = luaO_ceillog2(size);
+    if (lsize > MAXHBITS)
+      luaG_runerror(L, "table overflow");
+    size = twoto(lsize);
+    t->node = luaM_newvector(L, size, Node);
+    for (i = 0; i < (int)size; i++) {
+      Node *n = gnode(t, i);
+      gnext(n) = 0;
+      setnilvalue(wgkey(n));
+      setnilvalue(gval(n));
+    }
+  }
+  t->lsizenode = cast_byte(lsize);
+  t->lastfree = gnode(t, size);  /* all positions are free */
+}
+
+
+void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
+                                          unsigned int nhsize) {
+  unsigned int i;
+  int j;
+  unsigned int oldasize = t->sizearray;
+  int oldhsize = t->lsizenode;
+  Node *nold = t->node;  /* save old hash ... */
+  if (nasize > oldasize)  /* array part must grow? */
+    setarrayvector(L, t, nasize);
+  /* create new hash part with appropriate size */
+  setnodevector(L, t, nhsize);
+  if (nasize < oldasize) {  /* array part must shrink? */
+    t->sizearray = nasize;
+    /* re-insert elements from vanishing slice */
+    for (i=nasize; i<oldasize; i++) {
+      if (!ttisnil(&t->array[i]))
+        luaH_setint(L, t, i + 1, &t->array[i]);
+    }
+    /* shrink array */
+    luaM_reallocvector(L, t->array, oldasize, nasize, TValue);
+  }
+  /* re-insert elements from hash part */
+  for (j = twoto(oldhsize) - 1; j >= 0; j--) {
+    Node *old = nold + j;
+    if (!ttisnil(gval(old))) {
+      /* doesn't need barrier/invalidate cache, as entry was
+         already present in the table */
+      setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old));
+    }
+  }
+  if (!isdummy(nold))
+    luaM_freearray(L, nold, cast(size_t, twoto(oldhsize))); /* free old hash */
+}
+
+
+void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) {
+  int nsize = isdummy(t->node) ? 0 : sizenode(t);
+  luaH_resize(L, t, nasize, nsize);
+}
+
+/*
+** nums[i] = number of keys 'k' where 2^(i - 1) < k <= 2^i
+*/
+static void rehash (lua_State *L, Table *t, const TValue *ek) {
+  unsigned int asize;  /* optimal size for array part */
+  unsigned int na;  /* number of keys in the array part */
+  unsigned int nums[MAXABITS + 1];
+  int i;
+  int totaluse;
+  for (i = 0; i <= MAXABITS; i++) nums[i] = 0;  /* reset counts */
+  na = numusearray(t, nums);  /* count keys in array part */
+  totaluse = na;  /* all those keys are integer keys */
+  totaluse += numusehash(t, nums, &na);  /* count keys in hash part */
+  /* count extra key */
+  na += countint(ek, nums);
+  totaluse++;
+  /* compute new size for array part */
+  asize = computesizes(nums, &na);
+  /* resize the table to new computed sizes */
+  luaH_resize(L, t, asize, totaluse - na);
+}
+
+
+
+/*
+** }=============================================================
+*/
+
+
+Table *luaH_new (lua_State *L) {
+  GCObject *o = luaC_newobj(L, LUA_TTABLE, sizeof(Table));
+  Table *t = gco2t(o);
+  t->metatable = NULL;
+  t->flags = cast_byte(~0);
+  t->array = NULL;
+  t->sizearray = 0;
+  setnodevector(L, t, 0);
+  return t;
+}
+
+
+void luaH_free (lua_State *L, Table *t) {
+  if (!isdummy(t->node))
+    luaM_freearray(L, t->node, cast(size_t, sizenode(t)));
+  luaM_freearray(L, t->array, t->sizearray);
+  luaM_free(L, t);
+}
+
+
+static Node *getfreepos (Table *t) {
+  while (t->lastfree > t->node) {
+    t->lastfree--;
+    if (ttisnil(gkey(t->lastfree)))
+      return t->lastfree;
+  }
+  return NULL;  /* could not find a free place */
+}
+
+
+
+/*
+** inserts a new key into a hash table; first, check whether key's main
+** position is free. If not, check whether colliding node is in its main
+** position or not: if it is not, move colliding node to an empty place and
+** put new key in its main position; otherwise (colliding node is in its main
+** position), new key goes to an empty position.
+*/
+TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
+  Node *mp;
+  TValue aux;
+  if (ttisnil(key)) luaG_runerror(L, "table index is nil");
+  else if (ttisfloat(key)) {
+    lua_Integer k;
+    if (luaV_tointeger(key, &k, 0)) {  /* index is int? */
+      setivalue(&aux, k);
+      key = &aux;  /* insert it as an integer */
+    }
+    else if (luai_numisnan(fltvalue(key)))
+      luaG_runerror(L, "table index is NaN");
+  }
+  mp = mainposition(t, key);
+  if (!ttisnil(gval(mp)) || isdummy(mp)) {  /* main position is taken? */
+    Node *othern;
+    Node *f = getfreepos(t);  /* get a free place */
+    if (f == NULL) {  /* cannot find a free place? */
+      rehash(L, t, key);  /* grow table */
+      /* whatever called 'newkey' takes care of TM cache */
+      return luaH_set(L, t, key);  /* insert key into grown table */
+    }
+    lua_assert(!isdummy(f));
+    othern = mainposition(t, gkey(mp));
+    if (othern != mp) {  /* is colliding node out of its main position? */
+      /* yes; move colliding node into free position */
+      while (othern + gnext(othern) != mp)  /* find previous */
+        othern += gnext(othern);
+      gnext(othern) = cast_int(f - othern);  /* rechain to point to 'f' */
+      *f = *mp;  /* copy colliding node into free pos. (mp->next also goes) */
+      if (gnext(mp) != 0) {
+        gnext(f) += cast_int(mp - f);  /* correct 'next' */
+        gnext(mp) = 0;  /* now 'mp' is free */
+      }
+      setnilvalue(gval(mp));
+    }
+    else {  /* colliding node is in its own main position */
+      /* new node will go into free position */
+      if (gnext(mp) != 0)
+        gnext(f) = cast_int((mp + gnext(mp)) - f);  /* chain new position */
+      else lua_assert(gnext(f) == 0);
+      gnext(mp) = cast_int(f - mp);
+      mp = f;
+    }
+  }
+  setnodekey(L, &mp->i_key, key);
+  luaC_barrierback(L, t, key);
+  lua_assert(ttisnil(gval(mp)));
+  return gval(mp);
+}
+
+
+/*
+** search function for integers
+*/
+const TValue *luaH_getint (Table *t, lua_Integer key) {
+  /* (1 <= key && key <= t->sizearray) */
+  if (l_castS2U(key) - 1 < t->sizearray)
+    return &t->array[key - 1];
+  else {
+    Node *n = hashint(t, key);
+    for (;;) {  /* check whether 'key' is somewhere in the chain */
+      if (ttisinteger(gkey(n)) && ivalue(gkey(n)) == key)
+        return gval(n);  /* that's it */
+      else {
+        int nx = gnext(n);
+        if (nx == 0) break;
+        n += nx;
+      }
+    }
+    return luaO_nilobject;
+  }
+}
+
+
+/*
+** search function for short strings
+*/
+const TValue *luaH_getshortstr (Table *t, TString *key) {
+  Node *n = hashstr(t, key);
+  lua_assert(key->tt == LUA_TSHRSTR);
+  for (;;) {  /* check whether 'key' is somewhere in the chain */
+    const TValue *k = gkey(n);
+    if (ttisshrstring(k) && eqshrstr(tsvalue(k), key))
+      return gval(n);  /* that's it */
+    else {
+      int nx = gnext(n);
+      if (nx == 0)
+        return luaO_nilobject;  /* not found */
+      n += nx;
+    }
+  }
+}
+
+
+/*
+** "Generic" get version. (Not that generic: not valid for integers,
+** which may be in array part, nor for floats with integral values.)
+*/
+static const TValue *getgeneric (Table *t, const TValue *key) {
+  Node *n = mainposition(t, key);
+  for (;;) {  /* check whether 'key' is somewhere in the chain */
+    if (luaV_rawequalobj(gkey(n), key))
+      return gval(n);  /* that's it */
+    else {
+      int nx = gnext(n);
+      if (nx == 0)
+        return luaO_nilobject;  /* not found */
+      n += nx;
+    }
+  }
+}
+
+
+const TValue *luaH_getstr (Table *t, TString *key) {
+  if (key->tt == LUA_TSHRSTR)
+    return luaH_getshortstr(t, key);
+  else {  /* for long strings, use generic case */
+    TValue ko;
+    setsvalue(cast(lua_State *, NULL), &ko, key);
+    return getgeneric(t, &ko);
+  }
+}
+
+
+/*
+** main search function
+*/
+const TValue *luaH_get (Table *t, const TValue *key) {
+  switch (ttype(key)) {
+    case LUA_TSHRSTR: return luaH_getshortstr(t, tsvalue(key));
+    case LUA_TNUMINT: return luaH_getint(t, ivalue(key));
+    case LUA_TNIL: return luaO_nilobject;
+    case LUA_TNUMFLT: {
+      lua_Integer k;
+      if (luaV_tointeger(key, &k, 0)) /* index is int? */
+        return luaH_getint(t, k);  /* use specialized version */
+      /* else... */
+    }  /* FALLTHROUGH */
+    default:
+      return getgeneric(t, key);
+  }
+}
+
+
+/*
+** beware: when using this function you probably need to check a GC
+** barrier and invalidate the TM cache.
+*/
+TValue *luaH_set (lua_State *L, Table *t, const TValue *key) {
+  const TValue *p = luaH_get(t, key);
+  if (p != luaO_nilobject)
+    return cast(TValue *, p);
+  else return luaH_newkey(L, t, key);
+}
+
+
+void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
+  const TValue *p = luaH_getint(t, key);
+  TValue *cell;
+  if (p != luaO_nilobject)
+    cell = cast(TValue *, p);
+  else {
+    TValue k;
+    setivalue(&k, key);
+    cell = luaH_newkey(L, t, &k);
+  }
+  setobj2t(L, cell, value);
+}
+
+
+static int unbound_search (Table *t, unsigned int j) {
+  unsigned int i = j;  /* i is zero or a present index */
+  j++;
+  /* find 'i' and 'j' such that i is present and j is not */
+  while (!ttisnil(luaH_getint(t, j))) {
+    i = j;
+    if (j > cast(unsigned int, MAX_INT)/2) {  /* overflow? */
+      /* table was built with bad purposes: resort to linear search */
+      i = 1;
+      while (!ttisnil(luaH_getint(t, i))) i++;
+      return i - 1;
+    }
+    j *= 2;
+  }
+  /* now do a binary search between them */
+  while (j - i > 1) {
+    unsigned int m = (i+j)/2;
+    if (ttisnil(luaH_getint(t, m))) j = m;
+    else i = m;
+  }
+  return i;
+}
+
+
+/*
+** Try to find a boundary in table 't'. A 'boundary' is an integer index
+** such that t[i] is non-nil and t[i+1] is nil (and 0 if t[1] is nil).
+*/
+int luaH_getn (Table *t) {
+  unsigned int j = t->sizearray;
+  if (j > 0 && ttisnil(&t->array[j - 1])) {
+    /* there is a boundary in the array part: (binary) search for it */
+    unsigned int i = 0;
+    while (j - i > 1) {
+      unsigned int m = (i+j)/2;
+      if (ttisnil(&t->array[m - 1])) j = m;
+      else i = m;
+    }
+    return i;
+  }
+  /* else must find a boundary in hash part */
+  else if (isdummy(t->node))  /* hash part is empty? */
+    return j;  /* that is easy... */
+  else return unbound_search(t, j);
+}
+
+
+
+#if defined(LUA_DEBUG)
+
+Node *luaH_mainposition (const Table *t, const TValue *key) {
+  return mainposition(t, key);
+}
+
+int luaH_isdummy (Node *n) { return isdummy(n); }
+
+#endif
diff --git a/src/ltable.h b/src/ltable.h
new file mode 100644
index 0000000..213cc13
--- /dev/null
+++ b/src/ltable.h
@@ -0,0 +1,58 @@
+/*
+** $Id: ltable.h,v 2.21 2015/11/03 15:47:30 roberto Exp $
+** Lua tables (hash)
+** See Copyright Notice in lua.h
+*/
+
+#ifndef ltable_h
+#define ltable_h
+
+#include "lobject.h"
+
+
+#define gnode(t,i)	(&(t)->node[i])
+#define gval(n)		(&(n)->i_val)
+#define gnext(n)	((n)->i_key.nk.next)
+
+
+/* 'const' to avoid wrong writings that can mess up field 'next' */ 
+#define gkey(n)		cast(const TValue*, (&(n)->i_key.tvk))
+
+/*
+** writable version of 'gkey'; allows updates to individual fields,
+** but not to the whole (which has incompatible type)
+*/
+#define wgkey(n)		(&(n)->i_key.nk)
+
+#define invalidateTMcache(t)	((t)->flags = 0)
+
+
+/* returns the key, given the value of a table entry */
+#define keyfromval(v) \
+  (gkey(cast(Node *, cast(char *, (v)) - offsetof(Node, i_val))))
+
+
+LUAI_FUNC const TValue *luaH_getint (Table *t, lua_Integer key);
+LUAI_FUNC void luaH_setint (lua_State *L, Table *t, lua_Integer key,
+                                                    TValue *value);
+LUAI_FUNC const TValue *luaH_getshortstr (Table *t, TString *key);
+LUAI_FUNC const TValue *luaH_getstr (Table *t, TString *key);
+LUAI_FUNC const TValue *luaH_get (Table *t, const TValue *key);
+LUAI_FUNC TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key);
+LUAI_FUNC TValue *luaH_set (lua_State *L, Table *t, const TValue *key);
+LUAI_FUNC Table *luaH_new (lua_State *L);
+LUAI_FUNC void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
+                                                    unsigned int nhsize);
+LUAI_FUNC void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize);
+LUAI_FUNC void luaH_free (lua_State *L, Table *t);
+LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key);
+LUAI_FUNC int luaH_getn (Table *t);
+
+
+#if defined(LUA_DEBUG)
+LUAI_FUNC Node *luaH_mainposition (const Table *t, const TValue *key);
+LUAI_FUNC int luaH_isdummy (Node *n);
+#endif
+
+
+#endif
diff --git a/src/ltablib.c b/src/ltablib.c
new file mode 100644
index 0000000..98b2f87
--- /dev/null
+++ b/src/ltablib.c
@@ -0,0 +1,450 @@
+/*
+** $Id: ltablib.c,v 1.93 2016/02/25 19:41:54 roberto Exp $
+** Library for Table Manipulation
+** See Copyright Notice in lua.h
+*/
+
+#define ltablib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <limits.h>
+#include <stddef.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** Operations that an object must define to mimic a table
+** (some functions only need some of them)
+*/
+#define TAB_R	1			/* read */
+#define TAB_W	2			/* write */
+#define TAB_L	4			/* length */
+#define TAB_RW	(TAB_R | TAB_W)		/* read/write */
+
+
+#define aux_getn(L,n,w)	(checktab(L, n, (w) | TAB_L), luaL_len(L, n))
+
+
+static int checkfield (lua_State *L, const char *key, int n) {
+  lua_pushstring(L, key);
+  return (lua_rawget(L, -n) != LUA_TNIL);
+}
+
+
+/*
+** Check that 'arg' either is a table or can behave like one (that is,
+** has a metatable with the required metamethods)
+*/
+static void checktab (lua_State *L, int arg, int what) {
+  if (lua_type(L, arg) != LUA_TTABLE) {  /* is it not a table? */
+    int n = 1;  /* number of elements to pop */
+    if (lua_getmetatable(L, arg) &&  /* must have metatable */
+        (!(what & TAB_R) || checkfield(L, "__index", ++n)) &&
+        (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) &&
+        (!(what & TAB_L) || checkfield(L, "__len", ++n))) {
+      lua_pop(L, n);  /* pop metatable and tested metamethods */
+    }
+    else
+      luaL_checktype(L, arg, LUA_TTABLE);  /* force an error */
+  }
+}
+
+
+#if defined(LUA_COMPAT_MAXN)
+static int maxn (lua_State *L) {
+  lua_Number max = 0;
+  luaL_checktype(L, 1, LUA_TTABLE);
+  lua_pushnil(L);  /* first key */
+  while (lua_next(L, 1)) {
+    lua_pop(L, 1);  /* remove value */
+    if (lua_type(L, -1) == LUA_TNUMBER) {
+      lua_Number v = lua_tonumber(L, -1);
+      if (v > max) max = v;
+    }
+  }
+  lua_pushnumber(L, max);
+  return 1;
+}
+#endif
+
+
+static int tinsert (lua_State *L) {
+  lua_Integer e = aux_getn(L, 1, TAB_RW) + 1;  /* first empty element */
+  lua_Integer pos;  /* where to insert new element */
+  switch (lua_gettop(L)) {
+    case 2: {  /* called with only 2 arguments */
+      pos = e;  /* insert new element at the end */
+      break;
+    }
+    case 3: {
+      lua_Integer i;
+      pos = luaL_checkinteger(L, 2);  /* 2nd argument is the position */
+      luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
+      for (i = e; i > pos; i--) {  /* move up elements */
+        lua_geti(L, 1, i - 1);
+        lua_seti(L, 1, i);  /* t[i] = t[i - 1] */
+      }
+      break;
+    }
+    default: {
+      return luaL_error(L, "wrong number of arguments to 'insert'");
+    }
+  }
+  lua_seti(L, 1, pos);  /* t[pos] = v */
+  return 0;
+}
+
+
+static int tremove (lua_State *L) {
+  lua_Integer size = aux_getn(L, 1, TAB_RW);
+  lua_Integer pos = luaL_optinteger(L, 2, size);
+  if (pos != size)  /* validate 'pos' if given */
+    luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
+  lua_geti(L, 1, pos);  /* result = t[pos] */
+  for ( ; pos < size; pos++) {
+    lua_geti(L, 1, pos + 1);
+    lua_seti(L, 1, pos);  /* t[pos] = t[pos + 1] */
+  }
+  lua_pushnil(L);
+  lua_seti(L, 1, pos);  /* t[pos] = nil */
+  return 1;
+}
+
+
+/*
+** Copy elements (1[f], ..., 1[e]) into (tt[t], tt[t+1], ...). Whenever
+** possible, copy in increasing order, which is better for rehashing.
+** "possible" means destination after original range, or smaller
+** than origin, or copying to another table.
+*/
+static int tmove (lua_State *L) {
+  lua_Integer f = luaL_checkinteger(L, 2);
+  lua_Integer e = luaL_checkinteger(L, 3);
+  lua_Integer t = luaL_checkinteger(L, 4);
+  int tt = !lua_isnoneornil(L, 5) ? 5 : 1;  /* destination table */
+  checktab(L, 1, TAB_R);
+  checktab(L, tt, TAB_W);
+  if (e >= f) {  /* otherwise, nothing to move */
+    lua_Integer n, i;
+    luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
+                  "too many elements to move");
+    n = e - f + 1;  /* number of elements to move */
+    luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4,
+                  "destination wrap around");
+    if (t > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) {
+      for (i = 0; i < n; i++) {
+        lua_geti(L, 1, f + i);
+        lua_seti(L, tt, t + i);
+      }
+    }
+    else {
+      for (i = n - 1; i >= 0; i--) {
+        lua_geti(L, 1, f + i);
+        lua_seti(L, tt, t + i);
+      }
+    }
+  }
+  lua_pushvalue(L, tt);  /* return destination table */
+  return 1;
+}
+
+
+static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
+  lua_geti(L, 1, i);
+  if (!lua_isstring(L, -1))
+    luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
+                  luaL_typename(L, -1), i);
+  luaL_addvalue(b);
+}
+
+
+static int tconcat (lua_State *L) {
+  luaL_Buffer b;
+  lua_Integer last = aux_getn(L, 1, TAB_R);
+  size_t lsep;
+  const char *sep = luaL_optlstring(L, 2, "", &lsep);
+  lua_Integer i = luaL_optinteger(L, 3, 1);
+  last = luaL_optinteger(L, 4, last);
+  luaL_buffinit(L, &b);
+  for (; i < last; i++) {
+    addfield(L, &b, i);
+    luaL_addlstring(&b, sep, lsep);
+  }
+  if (i == last)  /* add last value (if interval was not empty) */
+    addfield(L, &b, i);
+  luaL_pushresult(&b);
+  return 1;
+}
+
+
+/*
+** {======================================================
+** Pack/unpack
+** =======================================================
+*/
+
+static int pack (lua_State *L) {
+  int i;
+  int n = lua_gettop(L);  /* number of elements to pack */
+  lua_createtable(L, n, 1);  /* create result table */
+  lua_insert(L, 1);  /* put it at index 1 */
+  for (i = n; i >= 1; i--)  /* assign elements */
+    lua_seti(L, 1, i);
+  lua_pushinteger(L, n);
+  lua_setfield(L, 1, "n");  /* t.n = number of elements */
+  return 1;  /* return table */
+}
+
+
+static int unpack (lua_State *L) {
+  lua_Unsigned n;
+  lua_Integer i = luaL_optinteger(L, 2, 1);
+  lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
+  if (i > e) return 0;  /* empty range */
+  n = (lua_Unsigned)e - i;  /* number of elements minus 1 (avoid overflows) */
+  if (n >= (unsigned int)INT_MAX  || !lua_checkstack(L, (int)(++n)))
+    return luaL_error(L, "too many results to unpack");
+  for (; i < e; i++) {  /* push arg[i..e - 1] (to avoid overflows) */
+    lua_geti(L, 1, i);
+  }
+  lua_geti(L, 1, e);  /* push last element */
+  return (int)n;
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** Quicksort
+** (based on 'Algorithms in MODULA-3', Robert Sedgewick;
+**  Addison-Wesley, 1993.)
+** =======================================================
+*/
+
+
+/* type for array indices */
+typedef unsigned int IdxT;
+
+
+/*
+** Produce a "random" 'unsigned int' to randomize pivot choice. This
+** macro is used only when 'sort' detects a big imbalance in the result
+** of a partition. (If you don't want/need this "randomness", ~0 is a
+** good choice.)
+*/
+#if !defined(l_randomizePivot)		/* { */
+
+#include <time.h>
+
+/* size of 'e' measured in number of 'unsigned int's */
+#define sof(e)		(sizeof(e) / sizeof(unsigned int))
+
+/*
+** Use 'time' and 'clock' as sources of "randomness". Because we don't
+** know the types 'clock_t' and 'time_t', we cannot cast them to
+** anything without risking overflows. A safe way to use their values
+** is to copy them to an array of a known type and use the array values.
+*/
+static unsigned int l_randomizePivot (void) {
+  clock_t c = clock();
+  time_t t = time(NULL);
+  unsigned int buff[sof(c) + sof(t)];
+  unsigned int i, rnd = 0;
+  memcpy(buff, &c, sof(c) * sizeof(unsigned int));
+  memcpy(buff + sof(c), &t, sof(t) * sizeof(unsigned int));
+  for (i = 0; i < sof(buff); i++)
+    rnd += buff[i];
+  return rnd;
+}
+
+#endif					/* } */
+
+
+/* arrays larger than 'RANLIMIT' may use randomized pivots */
+#define RANLIMIT	100u
+
+
+static void set2 (lua_State *L, IdxT i, IdxT j) {
+  lua_seti(L, 1, i);
+  lua_seti(L, 1, j);
+}
+
+
+/*
+** Return true iff value at stack index 'a' is less than the value at
+** index 'b' (according to the order of the sort).
+*/
+static int sort_comp (lua_State *L, int a, int b) {
+  if (lua_isnil(L, 2))  /* no function? */
+    return lua_compare(L, a, b, LUA_OPLT);  /* a < b */
+  else {  /* function */
+    int res;
+    lua_pushvalue(L, 2);    /* push function */
+    lua_pushvalue(L, a-1);  /* -1 to compensate function */
+    lua_pushvalue(L, b-2);  /* -2 to compensate function and 'a' */
+    lua_call(L, 2, 1);      /* call function */
+    res = lua_toboolean(L, -1);  /* get result */
+    lua_pop(L, 1);          /* pop result */
+    return res;
+  }
+}
+
+
+/*
+** Does the partition: Pivot P is at the top of the stack.
+** precondition: a[lo] <= P == a[up-1] <= a[up],
+** so it only needs to do the partition from lo + 1 to up - 2.
+** Pos-condition: a[lo .. i - 1] <= a[i] == P <= a[i + 1 .. up]
+** returns 'i'.
+*/
+static IdxT partition (lua_State *L, IdxT lo, IdxT up) {
+  IdxT i = lo;  /* will be incremented before first use */
+  IdxT j = up - 1;  /* will be decremented before first use */
+  /* loop invariant: a[lo .. i] <= P <= a[j .. up] */
+  for (;;) {
+    /* next loop: repeat ++i while a[i] < P */
+    while (lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
+      if (i == up - 1)  /* a[i] < P  but a[up - 1] == P  ?? */
+        luaL_error(L, "invalid order function for sorting");
+      lua_pop(L, 1);  /* remove a[i] */
+    }
+    /* after the loop, a[i] >= P and a[lo .. i - 1] < P */
+    /* next loop: repeat --j while P < a[j] */
+    while (lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
+      if (j < i)  /* j < i  but  a[j] > P ?? */
+        luaL_error(L, "invalid order function for sorting");
+      lua_pop(L, 1);  /* remove a[j] */
+    }
+    /* after the loop, a[j] <= P and a[j + 1 .. up] >= P */
+    if (j < i) {  /* no elements out of place? */
+      /* a[lo .. i - 1] <= P <= a[j + 1 .. i .. up] */
+      lua_pop(L, 1);  /* pop a[j] */
+      /* swap pivot (a[up - 1]) with a[i] to satisfy pos-condition */
+      set2(L, up - 1, i);
+      return i;
+    }
+    /* otherwise, swap a[i] - a[j] to restore invariant and repeat */
+    set2(L, i, j);
+  }
+}
+
+
+/*
+** Choose an element in the middle (2nd-3th quarters) of [lo,up]
+** "randomized" by 'rnd'
+*/
+static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) {
+  IdxT r4 = (up - lo) / 4;  /* range/4 */
+  IdxT p = rnd % (r4 * 2) + (lo + r4);
+  lua_assert(lo + r4 <= p && p <= up - r4);
+  return p;
+}
+
+
+/*
+** QuickSort algorithm (recursive function)
+*/
+static void auxsort (lua_State *L, IdxT lo, IdxT up,
+                                   unsigned int rnd) {
+  while (lo < up) {  /* loop for tail recursion */
+    IdxT p;  /* Pivot index */
+    IdxT n;  /* to be used later */
+    /* sort elements 'lo', 'p', and 'up' */
+    lua_geti(L, 1, lo);
+    lua_geti(L, 1, up);
+    if (sort_comp(L, -1, -2))  /* a[up] < a[lo]? */
+      set2(L, lo, up);  /* swap a[lo] - a[up] */
+    else
+      lua_pop(L, 2);  /* remove both values */
+    if (up - lo == 1)  /* only 2 elements? */
+      return;  /* already sorted */
+    if (up - lo < RANLIMIT || rnd == 0)  /* small interval or no randomize? */
+      p = (lo + up)/2;  /* middle element is a good pivot */
+    else  /* for larger intervals, it is worth a random pivot */
+      p = choosePivot(lo, up, rnd);
+    lua_geti(L, 1, p);
+    lua_geti(L, 1, lo);
+    if (sort_comp(L, -2, -1))  /* a[p] < a[lo]? */
+      set2(L, p, lo);  /* swap a[p] - a[lo] */
+    else {
+      lua_pop(L, 1);  /* remove a[lo] */
+      lua_geti(L, 1, up);
+      if (sort_comp(L, -1, -2))  /* a[up] < a[p]? */
+        set2(L, p, up);  /* swap a[up] - a[p] */
+      else
+        lua_pop(L, 2);
+    }
+    if (up - lo == 2)  /* only 3 elements? */
+      return;  /* already sorted */
+    lua_geti(L, 1, p);  /* get middle element (Pivot) */
+    lua_pushvalue(L, -1);  /* push Pivot */
+    lua_geti(L, 1, up - 1);  /* push a[up - 1] */
+    set2(L, p, up - 1);  /* swap Pivot (a[p]) with a[up - 1] */
+    p = partition(L, lo, up);
+    /* a[lo .. p - 1] <= a[p] == P <= a[p + 1 .. up] */
+    if (p - lo < up - p) {  /* lower interval is smaller? */
+      auxsort(L, lo, p - 1, rnd);  /* call recursively for lower interval */
+      n = p - lo;  /* size of smaller interval */
+      lo = p + 1;  /* tail call for [p + 1 .. up] (upper interval) */
+    }
+    else {
+      auxsort(L, p + 1, up, rnd);  /* call recursively for upper interval */
+      n = up - p;  /* size of smaller interval */
+      up = p - 1;  /* tail call for [lo .. p - 1]  (lower interval) */
+    }
+    if ((up - lo) / 128 > n) /* partition too imbalanced? */
+      rnd = l_randomizePivot();  /* try a new randomization */
+  }  /* tail call auxsort(L, lo, up, rnd) */
+}
+
+
+static int sort (lua_State *L) {
+  lua_Integer n = aux_getn(L, 1, TAB_RW);
+  if (n > 1) {  /* non-trivial interval? */
+    luaL_argcheck(L, n < INT_MAX, 1, "array too big");
+    if (!lua_isnoneornil(L, 2))  /* is there a 2nd argument? */
+      luaL_checktype(L, 2, LUA_TFUNCTION);  /* must be a function */
+    lua_settop(L, 2);  /* make sure there are two arguments */
+    auxsort(L, 1, (IdxT)n, 0);
+  }
+  return 0;
+}
+
+/* }====================================================== */
+
+
+static const luaL_Reg tab_funcs[] = {
+  {"concat", tconcat},
+#if defined(LUA_COMPAT_MAXN)
+  {"maxn", maxn},
+#endif
+  {"insert", tinsert},
+  {"pack", pack},
+  {"unpack", unpack},
+  {"remove", tremove},
+  {"move", tmove},
+  {"sort", sort},
+  {NULL, NULL}
+};
+
+
+LUAMOD_API int luaopen_table (lua_State *L) {
+  luaL_newlib(L, tab_funcs);
+#if defined(LUA_COMPAT_UNPACK)
+  /* _G.unpack = table.unpack */
+  lua_getfield(L, -1, "unpack");
+  lua_setglobal(L, "unpack");
+#endif
+  return 1;
+}
+
diff --git a/src/ltm.c b/src/ltm.c
new file mode 100644
index 0000000..4650cc2
--- /dev/null
+++ b/src/ltm.c
@@ -0,0 +1,165 @@
+/*
+** $Id: ltm.c,v 2.37 2016/02/26 19:20:15 roberto Exp $
+** Tag methods
+** See Copyright Notice in lua.h
+*/
+
+#define ltm_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h" 
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lvm.h"
+
+
+static const char udatatypename[] = "userdata";
+
+LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = {
+  "no value",
+  "nil", "boolean", udatatypename, "number",
+  "string", "table", "function", udatatypename, "thread",
+  "proto" /* this last case is used for tests only */
+};
+
+
+void luaT_init (lua_State *L) {
+  static const char *const luaT_eventname[] = {  /* ORDER TM */
+    "__index", "__newindex",
+    "__gc", "__mode", "__len", "__eq",
+    "__add", "__sub", "__mul", "__mod", "__pow",
+    "__div", "__idiv",
+    "__band", "__bor", "__bxor", "__shl", "__shr",
+    "__unm", "__bnot", "__lt", "__le",
+    "__concat", "__call"
+  };
+  int i;
+  for (i=0; i<TM_N; i++) {
+    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
+    luaC_fix(L, obj2gco(G(L)->tmname[i]));  /* never collect these names */
+  }
+}
+
+
+/*
+** function to be used with macro "fasttm": optimized for absence of
+** tag methods
+*/
+const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
+  const TValue *tm = luaH_getshortstr(events, ename);
+  lua_assert(event <= TM_EQ);
+  if (ttisnil(tm)) {  /* no tag method? */
+    events->flags |= cast_byte(1u<<event);  /* cache this fact */
+    return NULL;
+  }
+  else return tm;
+}
+
+
+const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
+  Table *mt;
+  switch (ttnov(o)) {
+    case LUA_TTABLE:
+      mt = hvalue(o)->metatable;
+      break;
+    case LUA_TUSERDATA:
+      mt = uvalue(o)->metatable;
+      break;
+    default:
+      mt = G(L)->mt[ttnov(o)];
+  }
+  return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : luaO_nilobject);
+}
+
+
+/*
+** Return the name of the type of an object. For tables and userdata
+** with metatable, use their '__name' metafield, if present.
+*/
+const char *luaT_objtypename (lua_State *L, const TValue *o) {
+  Table *mt;
+  if ((ttistable(o) && (mt = hvalue(o)->metatable) != NULL) ||
+      (ttisfulluserdata(o) && (mt = uvalue(o)->metatable) != NULL)) {
+    const TValue *name = luaH_getshortstr(mt, luaS_new(L, "__name"));
+    if (ttisstring(name))  /* is '__name' a string? */
+      return getstr(tsvalue(name));  /* use it as type name */
+  }
+  return ttypename(ttnov(o));  /* else use standard type name */
+}
+
+
+void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
+                  const TValue *p2, TValue *p3, int hasres) {
+  ptrdiff_t result = savestack(L, p3);
+  StkId func = L->top;
+  setobj2s(L, func, f);  /* push function (assume EXTRA_STACK) */
+  setobj2s(L, func + 1, p1);  /* 1st argument */
+  setobj2s(L, func + 2, p2);  /* 2nd argument */
+  L->top += 3;
+  if (!hasres)  /* no result? 'p3' is third argument */
+    setobj2s(L, L->top++, p3);  /* 3rd argument */
+  /* metamethod may yield only when called from Lua code */
+  if (isLua(L->ci))
+    luaD_call(L, func, hasres);
+  else
+    luaD_callnoyield(L, func, hasres);
+  if (hasres) {  /* if has result, move it to its place */
+    p3 = restorestack(L, result);
+    setobjs2s(L, p3, --L->top);
+  }
+}
+
+
+int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
+                    StkId res, TMS event) {
+  const TValue *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
+  if (ttisnil(tm))
+    tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
+  if (ttisnil(tm)) return 0;
+  luaT_callTM(L, tm, p1, p2, res, 1);
+  return 1;
+}
+
+
+void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
+                    StkId res, TMS event) {
+  if (!luaT_callbinTM(L, p1, p2, res, event)) {
+    switch (event) {
+      case TM_CONCAT:
+        luaG_concaterror(L, p1, p2);
+      /* call never returns, but to avoid warnings: *//* FALLTHROUGH */
+      case TM_BAND: case TM_BOR: case TM_BXOR:
+      case TM_SHL: case TM_SHR: case TM_BNOT: {
+        lua_Number dummy;
+        if (tonumber(p1, &dummy) && tonumber(p2, &dummy))
+          luaG_tointerror(L, p1, p2);
+        else
+          luaG_opinterror(L, p1, p2, "perform bitwise operation on");
+      }
+      /* calls never return, but to avoid warnings: *//* FALLTHROUGH */
+      default:
+        luaG_opinterror(L, p1, p2, "perform arithmetic on");
+    }
+  }
+}
+
+
+int luaT_callorderTM (lua_State *L, const TValue *p1, const TValue *p2,
+                      TMS event) {
+  if (!luaT_callbinTM(L, p1, p2, L->top, event))
+    return -1;  /* no metamethod */
+  else
+    return !l_isfalse(L->top);
+}
+
diff --git a/src/ltm.h b/src/ltm.h
new file mode 100644
index 0000000..63db726
--- /dev/null
+++ b/src/ltm.h
@@ -0,0 +1,76 @@
+/*
+** $Id: ltm.h,v 2.22 2016/02/26 19:20:15 roberto Exp $
+** Tag methods
+** See Copyright Notice in lua.h
+*/
+
+#ifndef ltm_h
+#define ltm_h
+
+
+#include "lobject.h"
+
+
+/*
+* WARNING: if you change the order of this enumeration,
+* grep "ORDER TM" and "ORDER OP"
+*/
+typedef enum {
+  TM_INDEX,
+  TM_NEWINDEX,
+  TM_GC,
+  TM_MODE,
+  TM_LEN,
+  TM_EQ,  /* last tag method with fast access */
+  TM_ADD,
+  TM_SUB,
+  TM_MUL,
+  TM_MOD,
+  TM_POW,
+  TM_DIV,
+  TM_IDIV,
+  TM_BAND,
+  TM_BOR,
+  TM_BXOR,
+  TM_SHL,
+  TM_SHR,
+  TM_UNM,
+  TM_BNOT,
+  TM_LT,
+  TM_LE,
+  TM_CONCAT,
+  TM_CALL,
+  TM_N		/* number of elements in the enum */
+} TMS;
+
+
+
+#define gfasttm(g,et,e) ((et) == NULL ? NULL : \
+  ((et)->flags & (1u<<(e))) ? NULL : luaT_gettm(et, e, (g)->tmname[e]))
+
+#define fasttm(l,et,e)	gfasttm(G(l), et, e)
+
+#define ttypename(x)	luaT_typenames_[(x) + 1]
+
+LUAI_DDEC const char *const luaT_typenames_[LUA_TOTALTAGS];
+
+
+LUAI_FUNC const char *luaT_objtypename (lua_State *L, const TValue *o);
+
+LUAI_FUNC const TValue *luaT_gettm (Table *events, TMS event, TString *ename);
+LUAI_FUNC const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o,
+                                                       TMS event);
+LUAI_FUNC void luaT_init (lua_State *L);
+
+LUAI_FUNC void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
+                            const TValue *p2, TValue *p3, int hasres);
+LUAI_FUNC int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
+                              StkId res, TMS event);
+LUAI_FUNC void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
+                              StkId res, TMS event);
+LUAI_FUNC int luaT_callorderTM (lua_State *L, const TValue *p1,
+                                const TValue *p2, TMS event);
+
+
+
+#endif
diff --git a/src/lua.c b/src/lua.c
new file mode 100644
index 0000000..545d23d
--- /dev/null
+++ b/src/lua.c
@@ -0,0 +1,609 @@
+/*
+** $Id: lua.c,v 1.226 2015/08/14 19:11:20 roberto Exp $
+** Lua stand-alone interpreter
+** See Copyright Notice in lua.h
+*/
+
+#define lua_c
+
+#include "lprefix.h"
+
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+#if !defined(LUA_PROMPT)
+#define LUA_PROMPT		"> "
+#define LUA_PROMPT2		">> "
+#endif
+
+#if !defined(LUA_PROGNAME)
+#define LUA_PROGNAME		"lua"
+#endif
+
+#if !defined(LUA_MAXINPUT)
+#define LUA_MAXINPUT		512
+#endif
+
+#if !defined(LUA_INIT_VAR)
+#define LUA_INIT_VAR		"LUA_INIT"
+#endif
+
+#define LUA_INITVARVERSION  \
+	LUA_INIT_VAR "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
+
+
+/*
+** lua_stdin_is_tty detects whether the standard input is a 'tty' (that
+** is, whether we're running lua interactively).
+*/
+#if !defined(lua_stdin_is_tty)	/* { */
+
+#if defined(LUA_USE_POSIX)	/* { */
+
+#include <unistd.h>
+#define lua_stdin_is_tty()	isatty(0)
+
+#elif defined(LUA_USE_WINDOWS)	/* }{ */
+
+#include <io.h>
+#define lua_stdin_is_tty()	_isatty(_fileno(stdin))
+
+#else				/* }{ */
+
+/* ISO C definition */
+#define lua_stdin_is_tty()	1  /* assume stdin is a tty */
+
+#endif				/* } */
+
+#endif				/* } */
+
+
+/*
+** lua_readline defines how to show a prompt and then read a line from
+** the standard input.
+** lua_saveline defines how to "save" a read line in a "history".
+** lua_freeline defines how to free a line read by lua_readline.
+*/
+#if !defined(lua_readline)	/* { */
+
+#if defined(LUA_USE_READLINE)	/* { */
+
+#include <readline/readline.h>
+#include <readline/history.h>
+#define lua_readline(L,b,p)	((void)L, ((b)=readline(p)) != NULL)
+#define lua_saveline(L,line)	((void)L, add_history(line))
+#define lua_freeline(L,b)	((void)L, free(b))
+
+#else				/* }{ */
+
+#define lua_readline(L,b,p) \
+        ((void)L, fputs(p, stdout), fflush(stdout),  /* show prompt */ \
+        fgets(b, LUA_MAXINPUT, stdin) != NULL)  /* get line */
+#define lua_saveline(L,line)	{ (void)L; (void)line; }
+#define lua_freeline(L,b)	{ (void)L; (void)b; }
+
+#endif				/* } */
+
+#endif				/* } */
+
+
+
+
+static lua_State *globalL = NULL;
+
+static const char *progname = LUA_PROGNAME;
+
+
+/*
+** Hook set by signal function to stop the interpreter.
+*/
+static void lstop (lua_State *L, lua_Debug *ar) {
+  (void)ar;  /* unused arg. */
+  lua_sethook(L, NULL, 0, 0);  /* reset hook */
+  luaL_error(L, "interrupted!");
+}
+
+
+/*
+** Function to be called at a C signal. Because a C signal cannot
+** just change a Lua state (as there is no proper synchronization),
+** this function only sets a hook that, when called, will stop the
+** interpreter.
+*/
+static void laction (int i) {
+  signal(i, SIG_DFL); /* if another SIGINT happens, terminate process */
+  lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
+}
+
+
+static void print_usage (const char *badoption) {
+  lua_writestringerror("%s: ", progname);
+  if (badoption[1] == 'e' || badoption[1] == 'l')
+    lua_writestringerror("'%s' needs argument\n", badoption);
+  else
+    lua_writestringerror("unrecognized option '%s'\n", badoption);
+  lua_writestringerror(
+  "usage: %s [options] [script [args]]\n"
+  "Available options are:\n"
+  "  -e stat  execute string 'stat'\n"
+  "  -i       enter interactive mode after executing 'script'\n"
+  "  -l name  require library 'name'\n"
+  "  -v       show version information\n"
+  "  -E       ignore environment variables\n"
+  "  --       stop handling options\n"
+  "  -        stop handling options and execute stdin\n"
+  ,
+  progname);
+}
+
+
+/*
+** Prints an error message, adding the program name in front of it
+** (if present)
+*/
+static void l_message (const char *pname, const char *msg) {
+  if (pname) lua_writestringerror("%s: ", pname);
+  lua_writestringerror("%s\n", msg);
+}
+
+
+/*
+** Check whether 'status' is not OK and, if so, prints the error
+** message on the top of the stack. It assumes that the error object
+** is a string, as it was either generated by Lua or by 'msghandler'.
+*/
+static int report (lua_State *L, int status) {
+  if (status != LUA_OK) {
+    const char *msg = lua_tostring(L, -1);
+    l_message(progname, msg);
+    lua_pop(L, 1);  /* remove message */
+  }
+  return status;
+}
+
+
+/*
+** Message handler used to run all chunks
+*/
+static int msghandler (lua_State *L) {
+  const char *msg = lua_tostring(L, 1);
+  if (msg == NULL) {  /* is error object not a string? */
+    if (luaL_callmeta(L, 1, "__tostring") &&  /* does it have a metamethod */
+        lua_type(L, -1) == LUA_TSTRING)  /* that produces a string? */
+      return 1;  /* that is the message */
+    else
+      msg = lua_pushfstring(L, "(error object is a %s value)",
+                               luaL_typename(L, 1));
+  }
+  luaL_traceback(L, L, msg, 1);  /* append a standard traceback */
+  return 1;  /* return the traceback */
+}
+
+
+/*
+** Interface to 'lua_pcall', which sets appropriate message function
+** and C-signal handler. Used to run all chunks.
+*/
+static int docall (lua_State *L, int narg, int nres) {
+  int status;
+  int base = lua_gettop(L) - narg;  /* function index */
+  lua_pushcfunction(L, msghandler);  /* push message handler */
+  lua_insert(L, base);  /* put it under function and args */
+  globalL = L;  /* to be available to 'laction' */
+  signal(SIGINT, laction);  /* set C-signal handler */
+  status = lua_pcall(L, narg, nres, base);
+  signal(SIGINT, SIG_DFL); /* reset C-signal handler */
+  lua_remove(L, base);  /* remove message handler from the stack */
+  return status;
+}
+
+
+static void print_version (void) {
+  lua_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));
+  lua_writeline();
+}
+
+
+/*
+** Create the 'arg' table, which stores all arguments from the
+** command line ('argv'). It should be aligned so that, at index 0,
+** it has 'argv[script]', which is the script name. The arguments
+** to the script (everything after 'script') go to positive indices;
+** other arguments (before the script name) go to negative indices.
+** If there is no script name, assume interpreter's name as base.
+*/
+static void createargtable (lua_State *L, char **argv, int argc, int script) {
+  int i, narg;
+  if (script == argc) script = 0;  /* no script name? */
+  narg = argc - (script + 1);  /* number of positive indices */
+  lua_createtable(L, narg, script + 1);
+  for (i = 0; i < argc; i++) {
+    lua_pushstring(L, argv[i]);
+    lua_rawseti(L, -2, i - script);
+  }
+  lua_setglobal(L, "arg");
+}
+
+
+static int dochunk (lua_State *L, int status) {
+  if (status == LUA_OK) status = docall(L, 0, 0);
+  return report(L, status);
+}
+
+
+static int dofile (lua_State *L, const char *name) {
+  return dochunk(L, luaL_loadfile(L, name));
+}
+
+
+static int dostring (lua_State *L, const char *s, const char *name) {
+  return dochunk(L, luaL_loadbuffer(L, s, strlen(s), name));
+}
+
+
+/*
+** Calls 'require(name)' and stores the result in a global variable
+** with the given name.
+*/
+static int dolibrary (lua_State *L, const char *name) {
+  int status;
+  lua_getglobal(L, "require");
+  lua_pushstring(L, name);
+  status = docall(L, 1, 1);  /* call 'require(name)' */
+  if (status == LUA_OK)
+    lua_setglobal(L, name);  /* global[name] = require return */
+  return report(L, status);
+}
+
+
+/*
+** Returns the string to be used as a prompt by the interpreter.
+*/
+static const char *get_prompt (lua_State *L, int firstline) {
+  const char *p;
+  lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2");
+  p = lua_tostring(L, -1);
+  if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
+  return p;
+}
+
+/* mark in error messages for incomplete statements */
+#define EOFMARK		"<eof>"
+#define marklen		(sizeof(EOFMARK)/sizeof(char) - 1)
+
+
+/*
+** Check whether 'status' signals a syntax error and the error
+** message at the top of the stack ends with the above mark for
+** incomplete statements.
+*/
+static int incomplete (lua_State *L, int status) {
+  if (status == LUA_ERRSYNTAX) {
+    size_t lmsg;
+    const char *msg = lua_tolstring(L, -1, &lmsg);
+    if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) {
+      lua_pop(L, 1);
+      return 1;
+    }
+  }
+  return 0;  /* else... */
+}
+
+
+/*
+** Prompt the user, read a line, and push it into the Lua stack.
+*/
+static int pushline (lua_State *L, int firstline) {
+  char buffer[LUA_MAXINPUT];
+  char *b = buffer;
+  size_t l;
+  const char *prmt = get_prompt(L, firstline);
+  int readstatus = lua_readline(L, b, prmt);
+  if (readstatus == 0)
+    return 0;  /* no input (prompt will be popped by caller) */
+  lua_pop(L, 1);  /* remove prompt */
+  l = strlen(b);
+  if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
+    b[--l] = '\0';  /* remove it */
+  if (firstline && b[0] == '=')  /* for compatibility with 5.2, ... */
+    lua_pushfstring(L, "return %s", b + 1);  /* change '=' to 'return' */
+  else
+    lua_pushlstring(L, b, l);
+  lua_freeline(L, b);
+  return 1;
+}
+
+
+/*
+** Try to compile line on the stack as 'return <line>;'; on return, stack
+** has either compiled chunk or original line (if compilation failed).
+*/
+static int addreturn (lua_State *L) {
+  const char *line = lua_tostring(L, -1);  /* original line */
+  const char *retline = lua_pushfstring(L, "return %s;", line);
+  int status = luaL_loadbuffer(L, retline, strlen(retline), "=stdin");
+  if (status == LUA_OK) {
+    lua_remove(L, -2);  /* remove modified line */
+    if (line[0] != '\0')  /* non empty? */
+      lua_saveline(L, line);  /* keep history */
+  }
+  else
+    lua_pop(L, 2);  /* pop result from 'luaL_loadbuffer' and modified line */
+  return status;
+}
+
+
+/*
+** Read multiple lines until a complete Lua statement
+*/
+static int multiline (lua_State *L) {
+  for (;;) {  /* repeat until gets a complete statement */
+    size_t len;
+    const char *line = lua_tolstring(L, 1, &len);  /* get what it has */
+    int status = luaL_loadbuffer(L, line, len, "=stdin");  /* try it */
+    if (!incomplete(L, status) || !pushline(L, 0)) {
+      lua_saveline(L, line);  /* keep history */
+      return status;  /* cannot or should not try to add continuation line */
+    }
+    lua_pushliteral(L, "\n");  /* add newline... */
+    lua_insert(L, -2);  /* ...between the two lines */
+    lua_concat(L, 3);  /* join them */
+  }
+}
+
+
+/*
+** Read a line and try to load (compile) it first as an expression (by
+** adding "return " in front of it) and second as a statement. Return
+** the final status of load/call with the resulting function (if any)
+** in the top of the stack.
+*/
+static int loadline (lua_State *L) {
+  int status;
+  lua_settop(L, 0);
+  if (!pushline(L, 1))
+    return -1;  /* no input */
+  if ((status = addreturn(L)) != LUA_OK)  /* 'return ...' did not work? */
+    status = multiline(L);  /* try as command, maybe with continuation lines */
+  lua_remove(L, 1);  /* remove line from the stack */
+  lua_assert(lua_gettop(L) == 1);
+  return status;
+}
+
+
+/*
+** Prints (calling the Lua 'print' function) any values on the stack
+*/
+static void l_print (lua_State *L) {
+  int n = lua_gettop(L);
+  if (n > 0) {  /* any result to be printed? */
+    luaL_checkstack(L, LUA_MINSTACK, "too many results to print");
+    lua_getglobal(L, "print");
+    lua_insert(L, 1);
+    if (lua_pcall(L, n, 0, 0) != LUA_OK)
+      l_message(progname, lua_pushfstring(L, "error calling 'print' (%s)",
+                                             lua_tostring(L, -1)));
+  }
+}
+
+
+/*
+** Do the REPL: repeatedly read (load) a line, evaluate (call) it, and
+** print any results.
+*/
+static void doREPL (lua_State *L) {
+  int status;
+  const char *oldprogname = progname;
+  progname = NULL;  /* no 'progname' on errors in interactive mode */
+  while ((status = loadline(L)) != -1) {
+    if (status == LUA_OK)
+      status = docall(L, 0, LUA_MULTRET);
+    if (status == LUA_OK) l_print(L);
+    else report(L, status);
+  }
+  lua_settop(L, 0);  /* clear stack */
+  lua_writeline();
+  progname = oldprogname;
+}
+
+
+/*
+** Push on the stack the contents of table 'arg' from 1 to #arg
+*/
+static int pushargs (lua_State *L) {
+  int i, n;
+  if (lua_getglobal(L, "arg") != LUA_TTABLE)
+    luaL_error(L, "'arg' is not a table");
+  n = (int)luaL_len(L, -1);
+  luaL_checkstack(L, n + 3, "too many arguments to script");
+  for (i = 1; i <= n; i++)
+    lua_rawgeti(L, -i, i);
+  lua_remove(L, -i);  /* remove table from the stack */
+  return n;
+}
+
+
+static int handle_script (lua_State *L, char **argv) {
+  int status;
+  const char *fname = argv[0];
+  if (strcmp(fname, "-") == 0 && strcmp(argv[-1], "--") != 0)
+    fname = NULL;  /* stdin */
+  status = luaL_loadfile(L, fname);
+  if (status == LUA_OK) {
+    int n = pushargs(L);  /* push arguments to script */
+    status = docall(L, n, LUA_MULTRET);
+  }
+  return report(L, status);
+}
+
+
+
+/* bits of various argument indicators in 'args' */
+#define has_error	1	/* bad option */
+#define has_i		2	/* -i */
+#define has_v		4	/* -v */
+#define has_e		8	/* -e */
+#define has_E		16	/* -E */
+
+/*
+** Traverses all arguments from 'argv', returning a mask with those
+** needed before running any Lua code (or an error code if it finds
+** any invalid argument). 'first' returns the first not-handled argument 
+** (either the script name or a bad argument in case of error).
+*/
+static int collectargs (char **argv, int *first) {
+  int args = 0;
+  int i;
+  for (i = 1; argv[i] != NULL; i++) {
+    *first = i;
+    if (argv[i][0] != '-')  /* not an option? */
+        return args;  /* stop handling options */
+    switch (argv[i][1]) {  /* else check option */
+      case '-':  /* '--' */
+        if (argv[i][2] != '\0')  /* extra characters after '--'? */
+          return has_error;  /* invalid option */
+        *first = i + 1;
+        return args;
+      case '\0':  /* '-' */
+        return args;  /* script "name" is '-' */
+      case 'E':
+        if (argv[i][2] != '\0')  /* extra characters after 1st? */
+          return has_error;  /* invalid option */
+        args |= has_E;
+        break;
+      case 'i':
+        args |= has_i;  /* (-i implies -v) *//* FALLTHROUGH */ 
+      case 'v':
+        if (argv[i][2] != '\0')  /* extra characters after 1st? */
+          return has_error;  /* invalid option */
+        args |= has_v;
+        break;
+      case 'e':
+        args |= has_e;  /* FALLTHROUGH */
+      case 'l':  /* both options need an argument */
+        if (argv[i][2] == '\0') {  /* no concatenated argument? */
+          i++;  /* try next 'argv' */
+          if (argv[i] == NULL || argv[i][0] == '-')
+            return has_error;  /* no next argument or it is another option */
+        }
+        break;
+      default:  /* invalid option */
+        return has_error;
+    }
+  }
+  *first = i;  /* no script name */
+  return args;
+}
+
+
+/*
+** Processes options 'e' and 'l', which involve running Lua code.
+** Returns 0 if some code raises an error.
+*/
+static int runargs (lua_State *L, char **argv, int n) {
+  int i;
+  for (i = 1; i < n; i++) {
+    int option = argv[i][1];
+    lua_assert(argv[i][0] == '-');  /* already checked */
+    if (option == 'e' || option == 'l') {
+      int status;
+      const char *extra = argv[i] + 2;  /* both options need an argument */
+      if (*extra == '\0') extra = argv[++i];
+      lua_assert(extra != NULL);
+      status = (option == 'e')
+               ? dostring(L, extra, "=(command line)")
+               : dolibrary(L, extra);
+      if (status != LUA_OK) return 0;
+    }
+  }
+  return 1;
+}
+
+
+static int handle_luainit (lua_State *L) {
+  const char *name = "=" LUA_INITVARVERSION;
+  const char *init = getenv(name + 1);
+  if (init == NULL) {
+    name = "=" LUA_INIT_VAR;
+    init = getenv(name + 1);  /* try alternative name */
+  }
+  if (init == NULL) return LUA_OK;
+  else if (init[0] == '@')
+    return dofile(L, init+1);
+  else
+    return dostring(L, init, name);
+}
+
+
+/*
+** Main body of stand-alone interpreter (to be called in protected mode).
+** Reads the options and handles them all.
+*/
+static int pmain (lua_State *L) {
+  int argc = (int)lua_tointeger(L, 1);
+  char **argv = (char **)lua_touserdata(L, 2);
+  int script;
+  int args = collectargs(argv, &script);
+  luaL_checkversion(L);  /* check that interpreter has correct version */
+  if (argv[0] && argv[0][0]) progname = argv[0];
+  if (args == has_error) {  /* bad arg? */
+    print_usage(argv[script]);  /* 'script' has index of bad arg. */
+    return 0;
+  }
+  if (args & has_v)  /* option '-v'? */
+    print_version();
+  if (args & has_E) {  /* option '-E'? */
+    lua_pushboolean(L, 1);  /* signal for libraries to ignore env. vars. */
+    lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
+  }
+  luaL_openlibs(L);  /* open standard libraries */
+  createargtable(L, argv, argc, script);  /* create table 'arg' */
+  if (!(args & has_E)) {  /* no option '-E'? */
+    if (handle_luainit(L) != LUA_OK)  /* run LUA_INIT */
+      return 0;  /* error running LUA_INIT */
+  }
+  if (!runargs(L, argv, script))  /* execute arguments -e and -l */
+    return 0;  /* something failed */
+  if (script < argc &&  /* execute main script (if there is one) */
+      handle_script(L, argv + script) != LUA_OK)
+    return 0;
+  if (args & has_i)  /* -i option? */
+    doREPL(L);  /* do read-eval-print loop */
+  else if (script == argc && !(args & (has_e | has_v))) {  /* no arguments? */
+    if (lua_stdin_is_tty()) {  /* running in interactive mode? */
+      print_version();
+      doREPL(L);  /* do read-eval-print loop */
+    }
+    else dofile(L, NULL);  /* executes stdin as a file */
+  }
+  lua_pushboolean(L, 1);  /* signal no errors */
+  return 1;
+}
+
+
+int main (int argc, char **argv) {
+  int status, result;
+  lua_State *L = luaL_newstate();  /* create state */
+  if (L == NULL) {
+    l_message(argv[0], "cannot create state: not enough memory");
+    return EXIT_FAILURE;
+  }
+  lua_pushcfunction(L, &pmain);  /* to call 'pmain' in protected mode */
+  lua_pushinteger(L, argc);  /* 1st argument */
+  lua_pushlightuserdata(L, argv); /* 2nd argument */
+  status = lua_pcall(L, 2, 1, 0);  /* do the call */
+  result = lua_toboolean(L, -1);  /* get result */
+  report(L, status);
+  lua_close(L);
+  return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
diff --git a/src/lua.h b/src/lua.h
new file mode 100644
index 0000000..f78899f
--- /dev/null
+++ b/src/lua.h
@@ -0,0 +1,486 @@
+/*
+** $Id: lua.h,v 1.331 2016/05/30 15:53:28 roberto Exp $
+** Lua - A Scripting Language
+** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
+** See Copyright Notice at the end of this file
+*/
+
+
+#ifndef lua_h
+#define lua_h
+
+#include <stdarg.h>
+#include <stddef.h>
+
+
+#include "luaconf.h"
+
+
+#define LUA_VERSION_MAJOR	"5"
+#define LUA_VERSION_MINOR	"3"
+#define LUA_VERSION_NUM		503
+#define LUA_VERSION_RELEASE	"3"
+
+#define LUA_VERSION	"Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
+#define LUA_RELEASE	LUA_VERSION "." LUA_VERSION_RELEASE
+#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2016 Lua.org, PUC-Rio"
+#define LUA_AUTHORS	"R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
+
+
+/* mark for precompiled code ('<esc>Lua') */
+#define LUA_SIGNATURE	"\x1bLua"
+
+/* option for multiple returns in 'lua_pcall' and 'lua_call' */
+#define LUA_MULTRET	(-1)
+
+
+/*
+** Pseudo-indices
+** (-LUAI_MAXSTACK is the minimum valid index; we keep some free empty
+** space after that to help overflow detection)
+*/
+#define LUA_REGISTRYINDEX	(-LUAI_MAXSTACK - 1000)
+#define lua_upvalueindex(i)	(LUA_REGISTRYINDEX - (i))
+
+
+/* thread status */
+#define LUA_OK		0
+#define LUA_YIELD	1
+#define LUA_ERRRUN	2
+#define LUA_ERRSYNTAX	3
+#define LUA_ERRMEM	4
+#define LUA_ERRGCMM	5
+#define LUA_ERRERR	6
+
+
+typedef struct lua_State lua_State;
+
+
+/*
+** basic types
+*/
+#define LUA_TNONE		(-1)
+
+#define LUA_TNIL		0
+#define LUA_TBOOLEAN		1
+#define LUA_TLIGHTUSERDATA	2
+#define LUA_TNUMBER		3
+#define LUA_TSTRING		4
+#define LUA_TTABLE		5
+#define LUA_TFUNCTION		6
+#define LUA_TUSERDATA		7
+#define LUA_TTHREAD		8
+
+#define LUA_NUMTAGS		9
+
+
+
+/* minimum Lua stack available to a C function */
+#define LUA_MINSTACK	20
+
+
+/* predefined values in the registry */
+#define LUA_RIDX_MAINTHREAD	1
+#define LUA_RIDX_GLOBALS	2
+#define LUA_RIDX_LAST		LUA_RIDX_GLOBALS
+
+
+/* type of numbers in Lua */
+typedef LUA_NUMBER lua_Number;
+
+
+/* type for integer functions */
+typedef LUA_INTEGER lua_Integer;
+
+/* unsigned integer type */
+typedef LUA_UNSIGNED lua_Unsigned;
+
+/* type for continuation-function contexts */
+typedef LUA_KCONTEXT lua_KContext;
+
+
+/*
+** Type for C functions registered with Lua
+*/
+typedef int (*lua_CFunction) (lua_State *L);
+
+/*
+** Type for continuation functions
+*/
+typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx);
+
+
+/*
+** Type for functions that read/write blocks when loading/dumping Lua chunks
+*/
+typedef const char * (*lua_Reader) (lua_State *L, void *ud, size_t *sz);
+
+typedef int (*lua_Writer) (lua_State *L, const void *p, size_t sz, void *ud);
+
+
+/*
+** Type for memory-allocation functions
+*/
+typedef void * (*lua_Alloc) (void *ud, void *ptr, size_t osize, size_t nsize);
+
+
+
+/*
+** generic extra include file
+*/
+#if defined(LUA_USER_H)
+#include LUA_USER_H
+#endif
+
+
+/*
+** RCS ident string
+*/
+extern const char lua_ident[];
+
+
+/*
+** state manipulation
+*/
+LUA_API lua_State *(lua_newstate) (lua_Alloc f, void *ud);
+LUA_API void       (lua_close) (lua_State *L);
+LUA_API lua_State *(lua_newthread) (lua_State *L);
+
+LUA_API lua_CFunction (lua_atpanic) (lua_State *L, lua_CFunction panicf);
+
+
+LUA_API const lua_Number *(lua_version) (lua_State *L);
+
+
+/*
+** basic stack manipulation
+*/
+LUA_API int   (lua_absindex) (lua_State *L, int idx);
+LUA_API int   (lua_gettop) (lua_State *L);
+LUA_API void  (lua_settop) (lua_State *L, int idx);
+LUA_API void  (lua_pushvalue) (lua_State *L, int idx);
+LUA_API void  (lua_rotate) (lua_State *L, int idx, int n);
+LUA_API void  (lua_copy) (lua_State *L, int fromidx, int toidx);
+LUA_API int   (lua_checkstack) (lua_State *L, int n);
+
+LUA_API void  (lua_xmove) (lua_State *from, lua_State *to, int n);
+
+
+/*
+** access functions (stack -> C)
+*/
+
+LUA_API int             (lua_isnumber) (lua_State *L, int idx);
+LUA_API int             (lua_isstring) (lua_State *L, int idx);
+LUA_API int             (lua_iscfunction) (lua_State *L, int idx);
+LUA_API int             (lua_isinteger) (lua_State *L, int idx);
+LUA_API int             (lua_isuserdata) (lua_State *L, int idx);
+LUA_API int             (lua_type) (lua_State *L, int idx);
+LUA_API const char     *(lua_typename) (lua_State *L, int tp);
+
+LUA_API lua_Number      (lua_tonumberx) (lua_State *L, int idx, int *isnum);
+LUA_API lua_Integer     (lua_tointegerx) (lua_State *L, int idx, int *isnum);
+LUA_API int             (lua_toboolean) (lua_State *L, int idx);
+LUA_API const char     *(lua_tolstring) (lua_State *L, int idx, size_t *len);
+LUA_API size_t          (lua_rawlen) (lua_State *L, int idx);
+LUA_API lua_CFunction   (lua_tocfunction) (lua_State *L, int idx);
+LUA_API void	       *(lua_touserdata) (lua_State *L, int idx);
+LUA_API lua_State      *(lua_tothread) (lua_State *L, int idx);
+LUA_API const void     *(lua_topointer) (lua_State *L, int idx);
+
+
+/*
+** Comparison and arithmetic functions
+*/
+
+#define LUA_OPADD	0	/* ORDER TM, ORDER OP */
+#define LUA_OPSUB	1
+#define LUA_OPMUL	2
+#define LUA_OPMOD	3
+#define LUA_OPPOW	4
+#define LUA_OPDIV	5
+#define LUA_OPIDIV	6
+#define LUA_OPBAND	7
+#define LUA_OPBOR	8
+#define LUA_OPBXOR	9
+#define LUA_OPSHL	10
+#define LUA_OPSHR	11
+#define LUA_OPUNM	12
+#define LUA_OPBNOT	13
+
+LUA_API void  (lua_arith) (lua_State *L, int op);
+
+#define LUA_OPEQ	0
+#define LUA_OPLT	1
+#define LUA_OPLE	2
+
+LUA_API int   (lua_rawequal) (lua_State *L, int idx1, int idx2);
+LUA_API int   (lua_compare) (lua_State *L, int idx1, int idx2, int op);
+
+
+/*
+** push functions (C -> stack)
+*/
+LUA_API void        (lua_pushnil) (lua_State *L);
+LUA_API void        (lua_pushnumber) (lua_State *L, lua_Number n);
+LUA_API void        (lua_pushinteger) (lua_State *L, lua_Integer n);
+LUA_API const char *(lua_pushlstring) (lua_State *L, const char *s, size_t len);
+LUA_API const char *(lua_pushstring) (lua_State *L, const char *s);
+LUA_API const char *(lua_pushvfstring) (lua_State *L, const char *fmt,
+                                                      va_list argp);
+LUA_API const char *(lua_pushfstring) (lua_State *L, const char *fmt, ...);
+LUA_API void  (lua_pushcclosure) (lua_State *L, lua_CFunction fn, int n);
+LUA_API void  (lua_pushboolean) (lua_State *L, int b);
+LUA_API void  (lua_pushlightuserdata) (lua_State *L, void *p);
+LUA_API int   (lua_pushthread) (lua_State *L);
+
+
+/*
+** get functions (Lua -> stack)
+*/
+LUA_API int (lua_getglobal) (lua_State *L, const char *name);
+LUA_API int (lua_gettable) (lua_State *L, int idx);
+LUA_API int (lua_getfield) (lua_State *L, int idx, const char *k);
+LUA_API int (lua_geti) (lua_State *L, int idx, lua_Integer n);
+LUA_API int (lua_rawget) (lua_State *L, int idx);
+LUA_API int (lua_rawgeti) (lua_State *L, int idx, lua_Integer n);
+LUA_API int (lua_rawgetp) (lua_State *L, int idx, const void *p);
+
+LUA_API void  (lua_createtable) (lua_State *L, int narr, int nrec);
+LUA_API void *(lua_newuserdata) (lua_State *L, size_t sz);
+LUA_API int   (lua_getmetatable) (lua_State *L, int objindex);
+LUA_API int  (lua_getuservalue) (lua_State *L, int idx);
+
+
+/*
+** set functions (stack -> Lua)
+*/
+LUA_API void  (lua_setglobal) (lua_State *L, const char *name);
+LUA_API void  (lua_settable) (lua_State *L, int idx);
+LUA_API void  (lua_setfield) (lua_State *L, int idx, const char *k);
+LUA_API void  (lua_seti) (lua_State *L, int idx, lua_Integer n);
+LUA_API void  (lua_rawset) (lua_State *L, int idx);
+LUA_API void  (lua_rawseti) (lua_State *L, int idx, lua_Integer n);
+LUA_API void  (lua_rawsetp) (lua_State *L, int idx, const void *p);
+LUA_API int   (lua_setmetatable) (lua_State *L, int objindex);
+LUA_API void  (lua_setuservalue) (lua_State *L, int idx);
+
+
+/*
+** 'load' and 'call' functions (load and run Lua code)
+*/
+LUA_API void  (lua_callk) (lua_State *L, int nargs, int nresults,
+                           lua_KContext ctx, lua_KFunction k);
+#define lua_call(L,n,r)		lua_callk(L, (n), (r), 0, NULL)
+
+LUA_API int   (lua_pcallk) (lua_State *L, int nargs, int nresults, int errfunc,
+                            lua_KContext ctx, lua_KFunction k);
+#define lua_pcall(L,n,r,f)	lua_pcallk(L, (n), (r), (f), 0, NULL)
+
+LUA_API int   (lua_load) (lua_State *L, lua_Reader reader, void *dt,
+                          const char *chunkname, const char *mode);
+
+LUA_API int (lua_dump) (lua_State *L, lua_Writer writer, void *data, int strip);
+
+
+/*
+** coroutine functions
+*/
+LUA_API int  (lua_yieldk)     (lua_State *L, int nresults, lua_KContext ctx,
+                               lua_KFunction k);
+LUA_API int  (lua_resume)     (lua_State *L, lua_State *from, int narg);
+LUA_API int  (lua_status)     (lua_State *L);
+LUA_API int (lua_isyieldable) (lua_State *L);
+
+#define lua_yield(L,n)		lua_yieldk(L, (n), 0, NULL)
+
+
+/*
+** garbage-collection function and options
+*/
+
+#define LUA_GCSTOP		0
+#define LUA_GCRESTART		1
+#define LUA_GCCOLLECT		2
+#define LUA_GCCOUNT		3
+#define LUA_GCCOUNTB		4
+#define LUA_GCSTEP		5
+#define LUA_GCSETPAUSE		6
+#define LUA_GCSETSTEPMUL	7
+#define LUA_GCISRUNNING		9
+
+LUA_API int (lua_gc) (lua_State *L, int what, int data);
+
+
+/*
+** miscellaneous functions
+*/
+
+LUA_API int   (lua_error) (lua_State *L);
+
+LUA_API int   (lua_next) (lua_State *L, int idx);
+
+LUA_API void  (lua_concat) (lua_State *L, int n);
+LUA_API void  (lua_len)    (lua_State *L, int idx);
+
+LUA_API size_t   (lua_stringtonumber) (lua_State *L, const char *s);
+
+LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud);
+LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
+
+
+
+/*
+** {==============================================================
+** some useful macros
+** ===============================================================
+*/
+
+#define lua_getextraspace(L)	((void *)((char *)(L) - LUA_EXTRASPACE))
+
+#define lua_tonumber(L,i)	lua_tonumberx(L,(i),NULL)
+#define lua_tointeger(L,i)	lua_tointegerx(L,(i),NULL)
+
+#define lua_pop(L,n)		lua_settop(L, -(n)-1)
+
+#define lua_newtable(L)		lua_createtable(L, 0, 0)
+
+#define lua_register(L,n,f) (lua_pushcfunction(L, (f)), lua_setglobal(L, (n)))
+
+#define lua_pushcfunction(L,f)	lua_pushcclosure(L, (f), 0)
+
+#define lua_isfunction(L,n)	(lua_type(L, (n)) == LUA_TFUNCTION)
+#define lua_istable(L,n)	(lua_type(L, (n)) == LUA_TTABLE)
+#define lua_islightuserdata(L,n)	(lua_type(L, (n)) == LUA_TLIGHTUSERDATA)
+#define lua_isnil(L,n)		(lua_type(L, (n)) == LUA_TNIL)
+#define lua_isboolean(L,n)	(lua_type(L, (n)) == LUA_TBOOLEAN)
+#define lua_isthread(L,n)	(lua_type(L, (n)) == LUA_TTHREAD)
+#define lua_isnone(L,n)		(lua_type(L, (n)) == LUA_TNONE)
+#define lua_isnoneornil(L, n)	(lua_type(L, (n)) <= 0)
+
+#define lua_pushliteral(L, s)	lua_pushstring(L, "" s)
+
+#define lua_pushglobaltable(L)  \
+	((void)lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS))
+
+#define lua_tostring(L,i)	lua_tolstring(L, (i), NULL)
+
+
+#define lua_insert(L,idx)	lua_rotate(L, (idx), 1)
+
+#define lua_remove(L,idx)	(lua_rotate(L, (idx), -1), lua_pop(L, 1))
+
+#define lua_replace(L,idx)	(lua_copy(L, -1, (idx)), lua_pop(L, 1))
+
+/* }============================================================== */
+
+
+/*
+** {==============================================================
+** compatibility macros for unsigned conversions
+** ===============================================================
+*/
+#if defined(LUA_COMPAT_APIINTCASTS)
+
+#define lua_pushunsigned(L,n)	lua_pushinteger(L, (lua_Integer)(n))
+#define lua_tounsignedx(L,i,is)	((lua_Unsigned)lua_tointegerx(L,i,is))
+#define lua_tounsigned(L,i)	lua_tounsignedx(L,(i),NULL)
+
+#endif
+/* }============================================================== */
+
+/*
+** {======================================================================
+** Debug API
+** =======================================================================
+*/
+
+
+/*
+** Event codes
+*/
+#define LUA_HOOKCALL	0
+#define LUA_HOOKRET	1
+#define LUA_HOOKLINE	2
+#define LUA_HOOKCOUNT	3
+#define LUA_HOOKTAILCALL 4
+
+
+/*
+** Event masks
+*/
+#define LUA_MASKCALL	(1 << LUA_HOOKCALL)
+#define LUA_MASKRET	(1 << LUA_HOOKRET)
+#define LUA_MASKLINE	(1 << LUA_HOOKLINE)
+#define LUA_MASKCOUNT	(1 << LUA_HOOKCOUNT)
+
+typedef struct lua_Debug lua_Debug;  /* activation record */
+
+
+/* Functions to be called by the debugger in specific events */
+typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
+
+
+LUA_API int (lua_getstack) (lua_State *L, int level, lua_Debug *ar);
+LUA_API int (lua_getinfo) (lua_State *L, const char *what, lua_Debug *ar);
+LUA_API const char *(lua_getlocal) (lua_State *L, const lua_Debug *ar, int n);
+LUA_API const char *(lua_setlocal) (lua_State *L, const lua_Debug *ar, int n);
+LUA_API const char *(lua_getupvalue) (lua_State *L, int funcindex, int n);
+LUA_API const char *(lua_setupvalue) (lua_State *L, int funcindex, int n);
+
+LUA_API void *(lua_upvalueid) (lua_State *L, int fidx, int n);
+LUA_API void  (lua_upvaluejoin) (lua_State *L, int fidx1, int n1,
+                                               int fidx2, int n2);
+
+LUA_API void (lua_sethook) (lua_State *L, lua_Hook func, int mask, int count);
+LUA_API lua_Hook (lua_gethook) (lua_State *L);
+LUA_API int (lua_gethookmask) (lua_State *L);
+LUA_API int (lua_gethookcount) (lua_State *L);
+
+
+struct lua_Debug {
+  int event;
+  const char *name;	/* (n) */
+  const char *namewhat;	/* (n) 'global', 'local', 'field', 'method' */
+  const char *what;	/* (S) 'Lua', 'C', 'main', 'tail' */
+  const char *source;	/* (S) */
+  int currentline;	/* (l) */
+  int linedefined;	/* (S) */
+  int lastlinedefined;	/* (S) */
+  unsigned char nups;	/* (u) number of upvalues */
+  unsigned char nparams;/* (u) number of parameters */
+  char isvararg;        /* (u) */
+  char istailcall;	/* (t) */
+  char short_src[LUA_IDSIZE]; /* (S) */
+  /* private part */
+  struct CallInfo *i_ci;  /* active function */
+};
+
+/* }====================================================================== */
+
+
+/******************************************************************************
+* Copyright (C) 1994-2016 Lua.org, PUC-Rio.
+*
+* Permission is hereby granted, free of charge, to any person obtaining
+* a copy of this software and associated documentation files (the
+* "Software"), to deal in the Software without restriction, including
+* without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to
+* permit persons to whom the Software is furnished to do so, subject to
+* the following conditions:
+*
+* The above copyright notice and this permission notice shall be
+* included in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+******************************************************************************/
+
+
+#endif
diff --git a/src/lua.hpp b/src/lua.hpp
new file mode 100644
index 0000000..ec417f5
--- /dev/null
+++ b/src/lua.hpp
@@ -0,0 +1,9 @@
+// lua.hpp
+// Lua header files for C++
+// <<extern "C">> not supplied automatically because Lua also compiles as C++
+
+extern "C" {
+#include "lua.h"
+#include "lualib.h"
+#include "lauxlib.h"
+}
diff --git a/src/luac.c b/src/luac.c
new file mode 100644
index 0000000..c0c91d0
--- /dev/null
+++ b/src/luac.c
@@ -0,0 +1,449 @@
+/*
+** $Id: luac.c,v 1.75 2015/03/12 01:58:27 lhf Exp $
+** Lua compiler (saves bytecodes to files; also lists bytecodes)
+** See Copyright Notice in lua.h
+*/
+
+#define luac_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+#include "lauxlib.h"
+
+#include "lobject.h"
+#include "lstate.h"
+#include "lundump.h"
+
+static void PrintFunction(const Proto* f, int full);
+#define luaU_print	PrintFunction
+
+#define PROGNAME	"luac"		/* default program name */
+#define OUTPUT		PROGNAME ".out"	/* default output file */
+
+static int listing=0;			/* list bytecodes? */
+static int dumping=1;			/* dump bytecodes? */
+static int stripping=0;			/* strip debug information? */
+static char Output[]={ OUTPUT };	/* default output file name */
+static const char* output=Output;	/* actual output file name */
+static const char* progname=PROGNAME;	/* actual program name */
+
+static void fatal(const char* message)
+{
+ fprintf(stderr,"%s: %s\n",progname,message);
+ exit(EXIT_FAILURE);
+}
+
+static void cannot(const char* what)
+{
+ fprintf(stderr,"%s: cannot %s %s: %s\n",progname,what,output,strerror(errno));
+ exit(EXIT_FAILURE);
+}
+
+static void usage(const char* message)
+{
+ if (*message=='-')
+  fprintf(stderr,"%s: unrecognized option '%s'\n",progname,message);
+ else
+  fprintf(stderr,"%s: %s\n",progname,message);
+ fprintf(stderr,
+  "usage: %s [options] [filenames]\n"
+  "Available options are:\n"
+  "  -l       list (use -l -l for full listing)\n"
+  "  -o name  output to file 'name' (default is \"%s\")\n"
+  "  -p       parse only\n"
+  "  -s       strip debug information\n"
+  "  -v       show version information\n"
+  "  --       stop handling options\n"
+  "  -        stop handling options and process stdin\n"
+  ,progname,Output);
+ exit(EXIT_FAILURE);
+}
+
+#define IS(s)	(strcmp(argv[i],s)==0)
+
+static int doargs(int argc, char* argv[])
+{
+ int i;
+ int version=0;
+ if (argv[0]!=NULL && *argv[0]!=0) progname=argv[0];
+ for (i=1; i<argc; i++)
+ {
+  if (*argv[i]!='-')			/* end of options; keep it */
+   break;
+  else if (IS("--"))			/* end of options; skip it */
+  {
+   ++i;
+   if (version) ++version;
+   break;
+  }
+  else if (IS("-"))			/* end of options; use stdin */
+   break;
+  else if (IS("-l"))			/* list */
+   ++listing;
+  else if (IS("-o"))			/* output file */
+  {
+   output=argv[++i];
+   if (output==NULL || *output==0 || (*output=='-' && output[1]!=0))
+    usage("'-o' needs argument");
+   if (IS("-")) output=NULL;
+  }
+  else if (IS("-p"))			/* parse only */
+   dumping=0;
+  else if (IS("-s"))			/* strip debug information */
+   stripping=1;
+  else if (IS("-v"))			/* show version */
+   ++version;
+  else					/* unknown option */
+   usage(argv[i]);
+ }
+ if (i==argc && (listing || !dumping))
+ {
+  dumping=0;
+  argv[--i]=Output;
+ }
+ if (version)
+ {
+  printf("%s\n",LUA_COPYRIGHT);
+  if (version==argc-1) exit(EXIT_SUCCESS);
+ }
+ return i;
+}
+
+#define FUNCTION "(function()end)();"
+
+static const char* reader(lua_State *L, void *ud, size_t *size)
+{
+ UNUSED(L);
+ if ((*(int*)ud)--)
+ {
+  *size=sizeof(FUNCTION)-1;
+  return FUNCTION;
+ }
+ else
+ {
+  *size=0;
+  return NULL;
+ }
+}
+
+#define toproto(L,i) getproto(L->top+(i))
+
+static const Proto* combine(lua_State* L, int n)
+{
+ if (n==1)
+  return toproto(L,-1);
+ else
+ {
+  Proto* f;
+  int i=n;
+  if (lua_load(L,reader,&i,"=(" PROGNAME ")",NULL)!=LUA_OK) fatal(lua_tostring(L,-1));
+  f=toproto(L,-1);
+  for (i=0; i<n; i++)
+  {
+   f->p[i]=toproto(L,i-n-1);
+   if (f->p[i]->sizeupvalues>0) f->p[i]->upvalues[0].instack=0;
+  }
+  f->sizelineinfo=0;
+  return f;
+ }
+}
+
+static int writer(lua_State* L, const void* p, size_t size, void* u)
+{
+ UNUSED(L);
+ return (fwrite(p,size,1,(FILE*)u)!=1) && (size!=0);
+}
+
+static int pmain(lua_State* L)
+{
+ int argc=(int)lua_tointeger(L,1);
+ char** argv=(char**)lua_touserdata(L,2);
+ const Proto* f;
+ int i;
+ if (!lua_checkstack(L,argc)) fatal("too many input files");
+ for (i=0; i<argc; i++)
+ {
+  const char* filename=IS("-") ? NULL : argv[i];
+  if (luaL_loadfile(L,filename)!=LUA_OK) fatal(lua_tostring(L,-1));
+ }
+ f=combine(L,argc);
+ if (listing) luaU_print(f,listing>1);
+ if (dumping)
+ {
+  FILE* D= (output==NULL) ? stdout : fopen(output,"wb");
+  if (D==NULL) cannot("open");
+  lua_lock(L);
+  luaU_dump(L,f,writer,D,stripping);
+  lua_unlock(L);
+  if (ferror(D)) cannot("write");
+  if (fclose(D)) cannot("close");
+ }
+ return 0;
+}
+
+int main(int argc, char* argv[])
+{
+ lua_State* L;
+ int i=doargs(argc,argv);
+ argc-=i; argv+=i;
+ if (argc<=0) usage("no input files given");
+ L=luaL_newstate();
+ if (L==NULL) fatal("cannot create state: not enough memory");
+ lua_pushcfunction(L,&pmain);
+ lua_pushinteger(L,argc);
+ lua_pushlightuserdata(L,argv);
+ if (lua_pcall(L,2,0,0)!=LUA_OK) fatal(lua_tostring(L,-1));
+ lua_close(L);
+ return EXIT_SUCCESS;
+}
+
+/*
+** $Id: luac.c,v 1.75 2015/03/12 01:58:27 lhf Exp $
+** print bytecodes
+** See Copyright Notice in lua.h
+*/
+
+#include <ctype.h>
+#include <stdio.h>
+
+#define luac_c
+#define LUA_CORE
+
+#include "ldebug.h"
+#include "lobject.h"
+#include "lopcodes.h"
+
+#define VOID(p)		((const void*)(p))
+
+static void PrintString(const TString* ts)
+{
+ const char* s=getstr(ts);
+ size_t i,n=tsslen(ts);
+ printf("%c",'"');
+ for (i=0; i<n; i++)
+ {
+  int c=(int)(unsigned char)s[i];
+  switch (c)
+  {
+   case '"':  printf("\\\""); break;
+   case '\\': printf("\\\\"); break;
+   case '\a': printf("\\a"); break;
+   case '\b': printf("\\b"); break;
+   case '\f': printf("\\f"); break;
+   case '\n': printf("\\n"); break;
+   case '\r': printf("\\r"); break;
+   case '\t': printf("\\t"); break;
+   case '\v': printf("\\v"); break;
+   default:	if (isprint(c))
+   			printf("%c",c);
+		else
+			printf("\\%03d",c);
+  }
+ }
+ printf("%c",'"');
+}
+
+static void PrintConstant(const Proto* f, int i)
+{
+ const TValue* o=&f->k[i];
+ switch (ttype(o))
+ {
+  case LUA_TNIL:
+	printf("nil");
+	break;
+  case LUA_TBOOLEAN:
+	printf(bvalue(o) ? "true" : "false");
+	break;
+  case LUA_TNUMFLT:
+	{
+	char buff[100];
+	sprintf(buff,LUA_NUMBER_FMT,fltvalue(o));
+	printf("%s",buff);
+	if (buff[strspn(buff,"-0123456789")]=='\0') printf(".0");
+	break;
+	}
+  case LUA_TNUMINT:
+	printf(LUA_INTEGER_FMT,ivalue(o));
+	break;
+  case LUA_TSHRSTR: case LUA_TLNGSTR:
+	PrintString(tsvalue(o));
+	break;
+  default:				/* cannot happen */
+	printf("? type=%d",ttype(o));
+	break;
+ }
+}
+
+#define UPVALNAME(x) ((f->upvalues[x].name) ? getstr(f->upvalues[x].name) : "-")
+#define MYK(x)		(-1-(x))
+
+static void PrintCode(const Proto* f)
+{
+ const Instruction* code=f->code;
+ int pc,n=f->sizecode;
+ for (pc=0; pc<n; pc++)
+ {
+  Instruction i=code[pc];
+  OpCode o=GET_OPCODE(i);
+  int a=GETARG_A(i);
+  int b=GETARG_B(i);
+  int c=GETARG_C(i);
+  int ax=GETARG_Ax(i);
+  int bx=GETARG_Bx(i);
+  int sbx=GETARG_sBx(i);
+  int line=getfuncline(f,pc);
+  printf("\t%d\t",pc+1);
+  if (line>0) printf("[%d]\t",line); else printf("[-]\t");
+  printf("%-9s\t",luaP_opnames[o]);
+  switch (getOpMode(o))
+  {
+   case iABC:
+    printf("%d",a);
+    if (getBMode(o)!=OpArgN) printf(" %d",ISK(b) ? (MYK(INDEXK(b))) : b);
+    if (getCMode(o)!=OpArgN) printf(" %d",ISK(c) ? (MYK(INDEXK(c))) : c);
+    break;
+   case iABx:
+    printf("%d",a);
+    if (getBMode(o)==OpArgK) printf(" %d",MYK(bx));
+    if (getBMode(o)==OpArgU) printf(" %d",bx);
+    break;
+   case iAsBx:
+    printf("%d %d",a,sbx);
+    break;
+   case iAx:
+    printf("%d",MYK(ax));
+    break;
+  }
+  switch (o)
+  {
+   case OP_LOADK:
+    printf("\t; "); PrintConstant(f,bx);
+    break;
+   case OP_GETUPVAL:
+   case OP_SETUPVAL:
+    printf("\t; %s",UPVALNAME(b));
+    break;
+   case OP_GETTABUP:
+    printf("\t; %s",UPVALNAME(b));
+    if (ISK(c)) { printf(" "); PrintConstant(f,INDEXK(c)); }
+    break;
+   case OP_SETTABUP:
+    printf("\t; %s",UPVALNAME(a));
+    if (ISK(b)) { printf(" "); PrintConstant(f,INDEXK(b)); }
+    if (ISK(c)) { printf(" "); PrintConstant(f,INDEXK(c)); }
+    break;
+   case OP_GETTABLE:
+   case OP_SELF:
+    if (ISK(c)) { printf("\t; "); PrintConstant(f,INDEXK(c)); }
+    break;
+   case OP_SETTABLE:
+   case OP_ADD:
+   case OP_SUB:
+   case OP_MUL:
+   case OP_POW:
+   case OP_DIV:
+   case OP_IDIV:
+   case OP_BAND:
+   case OP_BOR:
+   case OP_BXOR:
+   case OP_SHL:
+   case OP_SHR:
+   case OP_EQ:
+   case OP_LT:
+   case OP_LE:
+    if (ISK(b) || ISK(c))
+    {
+     printf("\t; ");
+     if (ISK(b)) PrintConstant(f,INDEXK(b)); else printf("-");
+     printf(" ");
+     if (ISK(c)) PrintConstant(f,INDEXK(c)); else printf("-");
+    }
+    break;
+   case OP_JMP:
+   case OP_FORLOOP:
+   case OP_FORPREP:
+   case OP_TFORLOOP:
+    printf("\t; to %d",sbx+pc+2);
+    break;
+   case OP_CLOSURE:
+    printf("\t; %p",VOID(f->p[bx]));
+    break;
+   case OP_SETLIST:
+    if (c==0) printf("\t; %d",(int)code[++pc]); else printf("\t; %d",c);
+    break;
+   case OP_EXTRAARG:
+    printf("\t; "); PrintConstant(f,ax);
+    break;
+   default:
+    break;
+  }
+  printf("\n");
+ }
+}
+
+#define SS(x)	((x==1)?"":"s")
+#define S(x)	(int)(x),SS(x)
+
+static void PrintHeader(const Proto* f)
+{
+ const char* s=f->source ? getstr(f->source) : "=?";
+ if (*s=='@' || *s=='=')
+  s++;
+ else if (*s==LUA_SIGNATURE[0])
+  s="(bstring)";
+ else
+  s="(string)";
+ printf("\n%s <%s:%d,%d> (%d instruction%s at %p)\n",
+ 	(f->linedefined==0)?"main":"function",s,
+	f->linedefined,f->lastlinedefined,
+	S(f->sizecode),VOID(f));
+ printf("%d%s param%s, %d slot%s, %d upvalue%s, ",
+	(int)(f->numparams),f->is_vararg?"+":"",SS(f->numparams),
+	S(f->maxstacksize),S(f->sizeupvalues));
+ printf("%d local%s, %d constant%s, %d function%s\n",
+	S(f->sizelocvars),S(f->sizek),S(f->sizep));
+}
+
+static void PrintDebug(const Proto* f)
+{
+ int i,n;
+ n=f->sizek;
+ printf("constants (%d) for %p:\n",n,VOID(f));
+ for (i=0; i<n; i++)
+ {
+  printf("\t%d\t",i+1);
+  PrintConstant(f,i);
+  printf("\n");
+ }
+ n=f->sizelocvars;
+ printf("locals (%d) for %p:\n",n,VOID(f));
+ for (i=0; i<n; i++)
+ {
+  printf("\t%d\t%s\t%d\t%d\n",
+  i,getstr(f->locvars[i].varname),f->locvars[i].startpc+1,f->locvars[i].endpc+1);
+ }
+ n=f->sizeupvalues;
+ printf("upvalues (%d) for %p:\n",n,VOID(f));
+ for (i=0; i<n; i++)
+ {
+  printf("\t%d\t%s\t%d\t%d\n",
+  i,UPVALNAME(i),f->upvalues[i].instack,f->upvalues[i].idx);
+ }
+}
+
+static void PrintFunction(const Proto* f, int full)
+{
+ int i,n=f->sizep;
+ PrintHeader(f);
+ PrintCode(f);
+ if (full) PrintDebug(f);
+ for (i=0; i<n; i++) PrintFunction(f->p[i],full);
+}
diff --git a/src/luaconf.h b/src/luaconf.h
new file mode 100644
index 0000000..fd447cc
--- /dev/null
+++ b/src/luaconf.h
@@ -0,0 +1,767 @@
+/*
+** $Id: luaconf.h,v 1.255 2016/05/01 20:06:09 roberto Exp $
+** Configuration file for Lua
+** See Copyright Notice in lua.h
+*/
+
+
+#ifndef luaconf_h
+#define luaconf_h
+
+#include <limits.h>
+#include <stddef.h>
+
+
+/*
+** ===================================================================
+** Search for "@@" to find all configurable definitions.
+** ===================================================================
+*/
+
+
+/*
+** {====================================================================
+** System Configuration: macros to adapt (if needed) Lua to some
+** particular platform, for instance compiling it with 32-bit numbers or
+** restricting it to C89.
+** =====================================================================
+*/
+
+/*
+@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats. You
+** can also define LUA_32BITS in the make file, but changing here you
+** ensure that all software connected to Lua will be compiled with the
+** same configuration.
+*/
+/* #define LUA_32BITS */
+
+
+/*
+@@ LUA_USE_C89 controls the use of non-ISO-C89 features.
+** Define it if you want Lua to avoid the use of a few C99 features
+** or Windows-specific features on Windows.
+*/
+/* #define LUA_USE_C89 */
+
+
+/*
+** By default, Lua on Windows use (some) specific Windows features
+*/
+#if !defined(LUA_USE_C89) && defined(_WIN32) && !defined(_WIN32_WCE)
+#define LUA_USE_WINDOWS  /* enable goodies for regular Windows */
+#endif
+
+
+#if defined(LUA_USE_WINDOWS)
+#define LUA_DL_DLL	/* enable support for DLL */
+#define LUA_USE_C89	/* broadly, Windows is C89 */
+#endif
+
+
+#if defined(LUA_USE_LINUX)
+#define LUA_USE_POSIX
+#define LUA_USE_DLOPEN		/* needs an extra library: -ldl */
+#define LUA_USE_READLINE	/* needs some extra libraries */
+#endif
+
+
+#if defined(LUA_USE_MACOSX)
+#define LUA_USE_POSIX
+#define LUA_USE_DLOPEN		/* MacOS does not need -ldl */
+#define LUA_USE_READLINE	/* needs an extra library: -lreadline */
+#endif
+
+
+/*
+@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for
+** C89 ('long' and 'double'); Windows always has '__int64', so it does
+** not need to use this case.
+*/
+#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS)
+#define LUA_C89_NUMBERS
+#endif
+
+
+
+/*
+@@ LUAI_BITSINT defines the (minimum) number of bits in an 'int'.
+*/
+/* avoid undefined shifts */
+#if ((INT_MAX >> 15) >> 15) >= 1
+#define LUAI_BITSINT	32
+#else
+/* 'int' always must have at least 16 bits */
+#define LUAI_BITSINT	16
+#endif
+
+
+/*
+@@ LUA_INT_TYPE defines the type for Lua integers.
+@@ LUA_FLOAT_TYPE defines the type for Lua floats.
+** Lua should work fine with any mix of these options (if supported
+** by your C compiler). The usual configurations are 64-bit integers
+** and 'double' (the default), 32-bit integers and 'float' (for
+** restricted platforms), and 'long'/'double' (for C compilers not
+** compliant with C99, which may not have support for 'long long').
+*/
+
+/* predefined options for LUA_INT_TYPE */
+#define LUA_INT_INT		1
+#define LUA_INT_LONG		2
+#define LUA_INT_LONGLONG	3
+
+/* predefined options for LUA_FLOAT_TYPE */
+#define LUA_FLOAT_FLOAT		1
+#define LUA_FLOAT_DOUBLE	2
+#define LUA_FLOAT_LONGDOUBLE	3
+
+#if defined(LUA_32BITS)		/* { */
+/*
+** 32-bit integers and 'float'
+*/
+#if LUAI_BITSINT >= 32  /* use 'int' if big enough */
+#define LUA_INT_TYPE	LUA_INT_INT
+#else  /* otherwise use 'long' */
+#define LUA_INT_TYPE	LUA_INT_LONG
+#endif
+#define LUA_FLOAT_TYPE	LUA_FLOAT_FLOAT
+
+#elif defined(LUA_C89_NUMBERS)	/* }{ */
+/*
+** largest types available for C89 ('long' and 'double')
+*/
+#define LUA_INT_TYPE	LUA_INT_LONG
+#define LUA_FLOAT_TYPE	LUA_FLOAT_DOUBLE
+
+#endif				/* } */
+
+
+/*
+** default configuration for 64-bit Lua ('long long' and 'double')
+*/
+#if !defined(LUA_INT_TYPE)
+#define LUA_INT_TYPE	LUA_INT_LONGLONG
+#endif
+
+#if !defined(LUA_FLOAT_TYPE)
+#define LUA_FLOAT_TYPE	LUA_FLOAT_DOUBLE
+#endif
+
+/* }================================================================== */
+
+
+
+
+/*
+** {==================================================================
+** Configuration for Paths.
+** ===================================================================
+*/
+
+/*
+@@ LUA_PATH_DEFAULT is the default path that Lua uses to look for
+** Lua libraries.
+@@ LUA_CPATH_DEFAULT is the default path that Lua uses to look for
+** C libraries.
+** CHANGE them if your machine has a non-conventional directory
+** hierarchy or if you want to install your libraries in
+** non-conventional directories.
+*/
+#define LUA_VDIR	LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
+#if defined(_WIN32)	/* { */
+/*
+** In Windows, any exclamation mark ('!') in the path is replaced by the
+** path of the directory of the executable file of the current process.
+*/
+#define LUA_LDIR	"!\\lua\\"
+#define LUA_CDIR	"!\\"
+#define LUA_SHRDIR	"!\\..\\share\\lua\\" LUA_VDIR "\\"
+#define LUA_PATH_DEFAULT  \
+		LUA_LDIR"?.lua;"  LUA_LDIR"?\\init.lua;" \
+		LUA_CDIR"?.lua;"  LUA_CDIR"?\\init.lua;" \
+		LUA_SHRDIR"?.lua;" LUA_SHRDIR"?\\init.lua;" \
+		".\\?.lua;" ".\\?\\init.lua"
+#define LUA_CPATH_DEFAULT \
+		LUA_CDIR"?.dll;" \
+		LUA_CDIR"..\\lib\\lua\\" LUA_VDIR "\\?.dll;" \
+		LUA_CDIR"loadall.dll;" ".\\?.dll"
+
+#else			/* }{ */
+
+#define LUA_ROOT	"/usr/local/"
+#define LUA_LDIR	LUA_ROOT "share/lua/" LUA_VDIR "/"
+#define LUA_CDIR	LUA_ROOT "lib/lua/" LUA_VDIR "/"
+#define LUA_PATH_DEFAULT  \
+		LUA_LDIR"?.lua;"  LUA_LDIR"?/init.lua;" \
+		LUA_CDIR"?.lua;"  LUA_CDIR"?/init.lua;" \
+		"./?.lua;" "./?/init.lua"
+#define LUA_CPATH_DEFAULT \
+		LUA_CDIR"?.so;" LUA_CDIR"loadall.so;" "./?.so"
+#endif			/* } */
+
+
+/*
+@@ LUA_DIRSEP is the directory separator (for submodules).
+** CHANGE it if your machine does not use "/" as the directory separator
+** and is not Windows. (On Windows Lua automatically uses "\".)
+*/
+#if defined(_WIN32)
+#define LUA_DIRSEP	"\\"
+#else
+#define LUA_DIRSEP	"/"
+#endif
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Marks for exported symbols in the C code
+** ===================================================================
+*/
+
+/*
+@@ LUA_API is a mark for all core API functions.
+@@ LUALIB_API is a mark for all auxiliary library functions.
+@@ LUAMOD_API is a mark for all standard library opening functions.
+** CHANGE them if you need to define those functions in some special way.
+** For instance, if you want to create one Windows DLL with the core and
+** the libraries, you may want to use the following definition (define
+** LUA_BUILD_AS_DLL to get it).
+*/
+#if defined(LUA_BUILD_AS_DLL)	/* { */
+
+#if defined(LUA_CORE) || defined(LUA_LIB)	/* { */
+#define LUA_API __declspec(dllexport)
+#else						/* }{ */
+#define LUA_API __declspec(dllimport)
+#endif						/* } */
+
+#else				/* }{ */
+
+#define LUA_API		extern
+
+#endif				/* } */
+
+
+/* more often than not the libs go together with the core */
+#define LUALIB_API	LUA_API
+#define LUAMOD_API	LUALIB_API
+
+
+/*
+@@ LUAI_FUNC is a mark for all extern functions that are not to be
+** exported to outside modules.
+@@ LUAI_DDEF and LUAI_DDEC are marks for all extern (const) variables
+** that are not to be exported to outside modules (LUAI_DDEF for
+** definitions and LUAI_DDEC for declarations).
+** CHANGE them if you need to mark them in some special way. Elf/gcc
+** (versions 3.2 and later) mark them as "hidden" to optimize access
+** when Lua is compiled as a shared library. Not all elf targets support
+** this attribute. Unfortunately, gcc does not offer a way to check
+** whether the target offers that support, and those without support
+** give a warning about it. To avoid these warnings, change to the
+** default definition.
+*/
+#if defined(__GNUC__) && ((__GNUC__*100 + __GNUC_MINOR__) >= 302) && \
+    defined(__ELF__)		/* { */
+#define LUAI_FUNC	__attribute__((visibility("hidden"))) extern
+#else				/* }{ */
+#define LUAI_FUNC	extern
+#endif				/* } */
+
+#define LUAI_DDEC	LUAI_FUNC
+#define LUAI_DDEF	/* empty */
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Compatibility with previous versions
+** ===================================================================
+*/
+
+/*
+@@ LUA_COMPAT_5_2 controls other macros for compatibility with Lua 5.2.
+@@ LUA_COMPAT_5_1 controls other macros for compatibility with Lua 5.1.
+** You can define it to get all options, or change specific options
+** to fit your specific needs.
+*/
+#if defined(LUA_COMPAT_5_2)	/* { */
+
+/*
+@@ LUA_COMPAT_MATHLIB controls the presence of several deprecated
+** functions in the mathematical library.
+*/
+#define LUA_COMPAT_MATHLIB
+
+/*
+@@ LUA_COMPAT_BITLIB controls the presence of library 'bit32'.
+*/
+#define LUA_COMPAT_BITLIB
+
+/*
+@@ LUA_COMPAT_IPAIRS controls the effectiveness of the __ipairs metamethod.
+*/
+#define LUA_COMPAT_IPAIRS
+
+/*
+@@ LUA_COMPAT_APIINTCASTS controls the presence of macros for
+** manipulating other integer types (lua_pushunsigned, lua_tounsigned,
+** luaL_checkint, luaL_checklong, etc.)
+*/
+#define LUA_COMPAT_APIINTCASTS
+
+#endif				/* } */
+
+
+#if defined(LUA_COMPAT_5_1)	/* { */
+
+/* Incompatibilities from 5.2 -> 5.3 */
+#define LUA_COMPAT_MATHLIB
+#define LUA_COMPAT_APIINTCASTS
+
+/*
+@@ LUA_COMPAT_UNPACK controls the presence of global 'unpack'.
+** You can replace it with 'table.unpack'.
+*/
+#define LUA_COMPAT_UNPACK
+
+/*
+@@ LUA_COMPAT_LOADERS controls the presence of table 'package.loaders'.
+** You can replace it with 'package.searchers'.
+*/
+#define LUA_COMPAT_LOADERS
+
+/*
+@@ macro 'lua_cpcall' emulates deprecated function lua_cpcall.
+** You can call your C function directly (with light C functions).
+*/
+#define lua_cpcall(L,f,u)  \
+	(lua_pushcfunction(L, (f)), \
+	 lua_pushlightuserdata(L,(u)), \
+	 lua_pcall(L,1,0,0))
+
+
+/*
+@@ LUA_COMPAT_LOG10 defines the function 'log10' in the math library.
+** You can rewrite 'log10(x)' as 'log(x, 10)'.
+*/
+#define LUA_COMPAT_LOG10
+
+/*
+@@ LUA_COMPAT_LOADSTRING defines the function 'loadstring' in the base
+** library. You can rewrite 'loadstring(s)' as 'load(s)'.
+*/
+#define LUA_COMPAT_LOADSTRING
+
+/*
+@@ LUA_COMPAT_MAXN defines the function 'maxn' in the table library.
+*/
+#define LUA_COMPAT_MAXN
+
+/*
+@@ The following macros supply trivial compatibility for some
+** changes in the API. The macros themselves document how to
+** change your code to avoid using them.
+*/
+#define lua_strlen(L,i)		lua_rawlen(L, (i))
+
+#define lua_objlen(L,i)		lua_rawlen(L, (i))
+
+#define lua_equal(L,idx1,idx2)		lua_compare(L,(idx1),(idx2),LUA_OPEQ)
+#define lua_lessthan(L,idx1,idx2)	lua_compare(L,(idx1),(idx2),LUA_OPLT)
+
+/*
+@@ LUA_COMPAT_MODULE controls compatibility with previous
+** module functions 'module' (Lua) and 'luaL_register' (C).
+*/
+#define LUA_COMPAT_MODULE
+
+#endif				/* } */
+
+
+/*
+@@ LUA_COMPAT_FLOATSTRING makes Lua format integral floats without a
+@@ a float mark ('.0').
+** This macro is not on by default even in compatibility mode,
+** because this is not really an incompatibility.
+*/
+/* #define LUA_COMPAT_FLOATSTRING */
+
+/* }================================================================== */
+
+
+
+/*
+** {==================================================================
+** Configuration for Numbers.
+** Change these definitions if no predefined LUA_FLOAT_* / LUA_INT_*
+** satisfy your needs.
+** ===================================================================
+*/
+
+/*
+@@ LUA_NUMBER is the floating-point type used by Lua.
+@@ LUAI_UACNUMBER is the result of an 'usual argument conversion'
+@@ over a floating number.
+@@ l_mathlim(x) corrects limit name 'x' to the proper float type
+** by prefixing it with one of FLT/DBL/LDBL.
+@@ LUA_NUMBER_FRMLEN is the length modifier for writing floats.
+@@ LUA_NUMBER_FMT is the format for writing floats.
+@@ lua_number2str converts a float to a string.
+@@ l_mathop allows the addition of an 'l' or 'f' to all math operations.
+@@ l_floor takes the floor of a float.
+@@ lua_str2number converts a decimal numeric string to a number.
+*/
+
+
+/* The following definitions are good for most cases here */
+
+#define l_floor(x)		(l_mathop(floor)(x))
+
+#define lua_number2str(s,sz,n)	l_sprintf((s), sz, LUA_NUMBER_FMT, (n))
+
+/*
+@@ lua_numbertointeger converts a float number to an integer, or
+** returns 0 if float is not within the range of a lua_Integer.
+** (The range comparisons are tricky because of rounding. The tests
+** here assume a two-complement representation, where MININTEGER always
+** has an exact representation as a float; MAXINTEGER may not have one,
+** and therefore its conversion to float may have an ill-defined value.)
+*/
+#define lua_numbertointeger(n,p) \
+  ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \
+   (n) < -(LUA_NUMBER)(LUA_MININTEGER) && \
+      (*(p) = (LUA_INTEGER)(n), 1))
+
+
+/* now the variable definitions */
+
+#if LUA_FLOAT_TYPE == LUA_FLOAT_FLOAT		/* { single float */
+
+#define LUA_NUMBER	float
+
+#define l_mathlim(n)		(FLT_##n)
+
+#define LUAI_UACNUMBER	double
+
+#define LUA_NUMBER_FRMLEN	""
+#define LUA_NUMBER_FMT		"%.7g"
+
+#define l_mathop(op)		op##f
+
+#define lua_str2number(s,p)	strtof((s), (p))
+
+
+#elif LUA_FLOAT_TYPE == LUA_FLOAT_LONGDOUBLE	/* }{ long double */
+
+#define LUA_NUMBER	long double
+
+#define l_mathlim(n)		(LDBL_##n)
+
+#define LUAI_UACNUMBER	long double
+
+#define LUA_NUMBER_FRMLEN	"L"
+#define LUA_NUMBER_FMT		"%.19Lg"
+
+#define l_mathop(op)		op##l
+
+#define lua_str2number(s,p)	strtold((s), (p))
+
+#elif LUA_FLOAT_TYPE == LUA_FLOAT_DOUBLE	/* }{ double */
+
+#define LUA_NUMBER	double
+
+#define l_mathlim(n)		(DBL_##n)
+
+#define LUAI_UACNUMBER	double
+
+#define LUA_NUMBER_FRMLEN	""
+#define LUA_NUMBER_FMT		"%.14g"
+
+#define l_mathop(op)		op
+
+#define lua_str2number(s,p)	strtod((s), (p))
+
+#else						/* }{ */
+
+#error "numeric float type not defined"
+
+#endif					/* } */
+
+
+
+/*
+@@ LUA_INTEGER is the integer type used by Lua.
+**
+@@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER.
+**
+@@ LUAI_UACINT is the result of an 'usual argument conversion'
+@@ over a lUA_INTEGER.
+@@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers.
+@@ LUA_INTEGER_FMT is the format for writing integers.
+@@ LUA_MAXINTEGER is the maximum value for a LUA_INTEGER.
+@@ LUA_MININTEGER is the minimum value for a LUA_INTEGER.
+@@ lua_integer2str converts an integer to a string.
+*/
+
+
+/* The following definitions are good for most cases here */
+
+#define LUA_INTEGER_FMT		"%" LUA_INTEGER_FRMLEN "d"
+#define lua_integer2str(s,sz,n)	l_sprintf((s), sz, LUA_INTEGER_FMT, (n))
+
+#define LUAI_UACINT		LUA_INTEGER
+
+/*
+** use LUAI_UACINT here to avoid problems with promotions (which
+** can turn a comparison between unsigneds into a signed comparison)
+*/
+#define LUA_UNSIGNED		unsigned LUAI_UACINT
+
+
+/* now the variable definitions */
+
+#if LUA_INT_TYPE == LUA_INT_INT		/* { int */
+
+#define LUA_INTEGER		int
+#define LUA_INTEGER_FRMLEN	""
+
+#define LUA_MAXINTEGER		INT_MAX
+#define LUA_MININTEGER		INT_MIN
+
+#elif LUA_INT_TYPE == LUA_INT_LONG	/* }{ long */
+
+#define LUA_INTEGER		long
+#define LUA_INTEGER_FRMLEN	"l"
+
+#define LUA_MAXINTEGER		LONG_MAX
+#define LUA_MININTEGER		LONG_MIN
+
+#elif LUA_INT_TYPE == LUA_INT_LONGLONG	/* }{ long long */
+
+/* use presence of macro LLONG_MAX as proxy for C99 compliance */
+#if defined(LLONG_MAX)		/* { */
+/* use ISO C99 stuff */
+
+#define LUA_INTEGER		long long
+#define LUA_INTEGER_FRMLEN	"ll"
+
+#define LUA_MAXINTEGER		LLONG_MAX
+#define LUA_MININTEGER		LLONG_MIN
+
+#elif defined(LUA_USE_WINDOWS) /* }{ */
+/* in Windows, can use specific Windows types */
+
+#define LUA_INTEGER		__int64
+#define LUA_INTEGER_FRMLEN	"I64"
+
+#define LUA_MAXINTEGER		_I64_MAX
+#define LUA_MININTEGER		_I64_MIN
+
+#else				/* }{ */
+
+#error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' \
+  or '-DLUA_C89_NUMBERS' (see file 'luaconf.h' for details)"
+
+#endif				/* } */
+
+#else				/* }{ */
+
+#error "numeric integer type not defined"
+
+#endif				/* } */
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Dependencies with C99 and other C details
+** ===================================================================
+*/
+
+/*
+@@ l_sprintf is equivalent to 'snprintf' or 'sprintf' in C89.
+** (All uses in Lua have only one format item.)
+*/
+#if !defined(LUA_USE_C89)
+#define l_sprintf(s,sz,f,i)	snprintf(s,sz,f,i)
+#else
+#define l_sprintf(s,sz,f,i)	((void)(sz), sprintf(s,f,i))
+#endif
+
+
+/*
+@@ lua_strx2number converts an hexadecimal numeric string to a number.
+** In C99, 'strtod' does that conversion. Otherwise, you can
+** leave 'lua_strx2number' undefined and Lua will provide its own
+** implementation.
+*/
+#if !defined(LUA_USE_C89)
+#define lua_strx2number(s,p)		lua_str2number(s,p)
+#endif
+
+
+/*
+@@ lua_number2strx converts a float to an hexadecimal numeric string. 
+** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that.
+** Otherwise, you can leave 'lua_number2strx' undefined and Lua will
+** provide its own implementation.
+*/
+#if !defined(LUA_USE_C89)
+#define lua_number2strx(L,b,sz,f,n)	((void)L, l_sprintf(b,sz,f,n))
+#endif
+
+
+/*
+** 'strtof' and 'opf' variants for math functions are not valid in
+** C89. Otherwise, the macro 'HUGE_VALF' is a good proxy for testing the
+** availability of these variants. ('math.h' is already included in
+** all files that use these macros.)
+*/
+#if defined(LUA_USE_C89) || (defined(HUGE_VAL) && !defined(HUGE_VALF))
+#undef l_mathop  /* variants not available */
+#undef lua_str2number
+#define l_mathop(op)		(lua_Number)op  /* no variant */
+#define lua_str2number(s,p)	((lua_Number)strtod((s), (p)))
+#endif
+
+
+/*
+@@ LUA_KCONTEXT is the type of the context ('ctx') for continuation
+** functions.  It must be a numerical type; Lua will use 'intptr_t' if
+** available, otherwise it will use 'ptrdiff_t' (the nearest thing to
+** 'intptr_t' in C89)
+*/
+#define LUA_KCONTEXT	ptrdiff_t
+
+#if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \
+    __STDC_VERSION__ >= 199901L
+#include <stdint.h>
+#if defined(INTPTR_MAX)  /* even in C99 this type is optional */
+#undef LUA_KCONTEXT
+#define LUA_KCONTEXT	intptr_t
+#endif
+#endif
+
+
+/*
+@@ lua_getlocaledecpoint gets the locale "radix character" (decimal point).
+** Change that if you do not want to use C locales. (Code using this
+** macro must include header 'locale.h'.)
+*/
+#if !defined(lua_getlocaledecpoint)
+#define lua_getlocaledecpoint()		(localeconv()->decimal_point[0])
+#endif
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Language Variations
+** =====================================================================
+*/
+
+/*
+@@ LUA_NOCVTN2S/LUA_NOCVTS2N control how Lua performs some
+** coercions. Define LUA_NOCVTN2S to turn off automatic coercion from
+** numbers to strings. Define LUA_NOCVTS2N to turn off automatic
+** coercion from strings to numbers.
+*/
+/* #define LUA_NOCVTN2S */
+/* #define LUA_NOCVTS2N */
+
+
+/*
+@@ LUA_USE_APICHECK turns on several consistency checks on the C API.
+** Define it as a help when debugging C code.
+*/
+#if defined(LUA_USE_APICHECK)
+#include <assert.h>
+#define luai_apicheck(l,e)	assert(e)
+#endif
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Macros that affect the API and must be stable (that is, must be the
+** same when you compile Lua and when you compile code that links to
+** Lua). You probably do not want/need to change them.
+** =====================================================================
+*/
+
+/*
+@@ LUAI_MAXSTACK limits the size of the Lua stack.
+** CHANGE it if you need a different limit. This limit is arbitrary;
+** its only purpose is to stop Lua from consuming unlimited stack
+** space (and to reserve some numbers for pseudo-indices).
+*/
+#if LUAI_BITSINT >= 32
+#define LUAI_MAXSTACK		1000000
+#else
+#define LUAI_MAXSTACK		15000
+#endif
+
+
+/*
+@@ LUA_EXTRASPACE defines the size of a raw memory area associated with
+** a Lua state with very fast access.
+** CHANGE it if you need a different size.
+*/
+#define LUA_EXTRASPACE		(sizeof(void *))
+
+
+/*
+@@ LUA_IDSIZE gives the maximum size for the description of the source
+@@ of a function in debug information.
+** CHANGE it if you want a different size.
+*/
+#define LUA_IDSIZE	60
+
+
+/*
+@@ LUAL_BUFFERSIZE is the buffer size used by the lauxlib buffer system.
+** CHANGE it if it uses too much C-stack space. (For long double,
+** 'string.format("%.99f", 1e4932)' needs ~5030 bytes, so a
+** smaller buffer would force a memory allocation for each call to
+** 'string.format'.)
+*/
+#if defined(LUA_FLOAT_LONGDOUBLE)
+#define LUAL_BUFFERSIZE		8192
+#else
+#define LUAL_BUFFERSIZE   ((int)(0x80 * sizeof(void*) * sizeof(lua_Integer)))
+#endif
+
+/* }================================================================== */
+
+
+/*
+@@ LUA_QL describes how error messages quote program elements.
+** Lua does not use these macros anymore; they are here for
+** compatibility only.
+*/
+#define LUA_QL(x)	"'" x "'"
+#define LUA_QS		LUA_QL("%s")
+
+
+
+
+/* =================================================================== */
+
+/*
+** Local configuration. You can use this space to add your redefinitions
+** without modifying the main part of the file.
+*/
+
+
+
+
+
+#endif
+
diff --git a/src/lualib.h b/src/lualib.h
new file mode 100644
index 0000000..5165c0f
--- /dev/null
+++ b/src/lualib.h
@@ -0,0 +1,58 @@
+/*
+** $Id: lualib.h,v 1.44 2014/02/06 17:32:33 roberto Exp $
+** Lua standard libraries
+** See Copyright Notice in lua.h
+*/
+
+
+#ifndef lualib_h
+#define lualib_h
+
+#include "lua.h"
+
+
+
+LUAMOD_API int (luaopen_base) (lua_State *L);
+
+#define LUA_COLIBNAME	"coroutine"
+LUAMOD_API int (luaopen_coroutine) (lua_State *L);
+
+#define LUA_TABLIBNAME	"table"
+LUAMOD_API int (luaopen_table) (lua_State *L);
+
+#define LUA_IOLIBNAME	"io"
+LUAMOD_API int (luaopen_io) (lua_State *L);
+
+#define LUA_OSLIBNAME	"os"
+LUAMOD_API int (luaopen_os) (lua_State *L);
+
+#define LUA_STRLIBNAME	"string"
+LUAMOD_API int (luaopen_string) (lua_State *L);
+
+#define LUA_UTF8LIBNAME	"utf8"
+LUAMOD_API int (luaopen_utf8) (lua_State *L);
+
+#define LUA_BITLIBNAME	"bit32"
+LUAMOD_API int (luaopen_bit32) (lua_State *L);
+
+#define LUA_MATHLIBNAME	"math"
+LUAMOD_API int (luaopen_math) (lua_State *L);
+
+#define LUA_DBLIBNAME	"debug"
+LUAMOD_API int (luaopen_debug) (lua_State *L);
+
+#define LUA_LOADLIBNAME	"package"
+LUAMOD_API int (luaopen_package) (lua_State *L);
+
+
+/* open all previous libraries */
+LUALIB_API void (luaL_openlibs) (lua_State *L);
+
+
+
+#if !defined(lua_assert)
+#define lua_assert(x)	((void)0)
+#endif
+
+
+#endif
diff --git a/src/lundump.c b/src/lundump.c
new file mode 100644
index 0000000..4080af9
--- /dev/null
+++ b/src/lundump.c
@@ -0,0 +1,279 @@
+/*
+** $Id: lundump.c,v 2.44 2015/11/02 16:09:30 roberto Exp $
+** load precompiled Lua chunks
+** See Copyright Notice in lua.h
+*/
+
+#define lundump_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstring.h"
+#include "lundump.h"
+#include "lzio.h"
+
+
+#if !defined(luai_verifycode)
+#define luai_verifycode(L,b,f)  /* empty */
+#endif
+
+
+typedef struct {
+  lua_State *L;
+  ZIO *Z;
+  const char *name;
+} LoadState;
+
+
+static l_noret error(LoadState *S, const char *why) {
+  luaO_pushfstring(S->L, "%s: %s precompiled chunk", S->name, why);
+  luaD_throw(S->L, LUA_ERRSYNTAX);
+}
+
+
+/*
+** All high-level loads go through LoadVector; you can change it to
+** adapt to the endianness of the input
+*/
+#define LoadVector(S,b,n)	LoadBlock(S,b,(n)*sizeof((b)[0]))
+
+static void LoadBlock (LoadState *S, void *b, size_t size) {
+  if (luaZ_read(S->Z, b, size) != 0)
+    error(S, "truncated");
+}
+
+
+#define LoadVar(S,x)		LoadVector(S,&x,1)
+
+
+static lu_byte LoadByte (LoadState *S) {
+  lu_byte x;
+  LoadVar(S, x);
+  return x;
+}
+
+
+static int LoadInt (LoadState *S) {
+  int x;
+  LoadVar(S, x);
+  return x;
+}
+
+
+static lua_Number LoadNumber (LoadState *S) {
+  lua_Number x;
+  LoadVar(S, x);
+  return x;
+}
+
+
+static lua_Integer LoadInteger (LoadState *S) {
+  lua_Integer x;
+  LoadVar(S, x);
+  return x;
+}
+
+
+static TString *LoadString (LoadState *S) {
+  size_t size = LoadByte(S);
+  if (size == 0xFF)
+    LoadVar(S, size);
+  if (size == 0)
+    return NULL;
+  else if (--size <= LUAI_MAXSHORTLEN) {  /* short string? */
+    char buff[LUAI_MAXSHORTLEN];
+    LoadVector(S, buff, size);
+    return luaS_newlstr(S->L, buff, size);
+  }
+  else {  /* long string */
+    TString *ts = luaS_createlngstrobj(S->L, size);
+    LoadVector(S, getstr(ts), size);  /* load directly in final place */
+    return ts;
+  }
+}
+
+
+static void LoadCode (LoadState *S, Proto *f) {
+  int n = LoadInt(S);
+  f->code = luaM_newvector(S->L, n, Instruction);
+  f->sizecode = n;
+  LoadVector(S, f->code, n);
+}
+
+
+static void LoadFunction(LoadState *S, Proto *f, TString *psource);
+
+
+static void LoadConstants (LoadState *S, Proto *f) {
+  int i;
+  int n = LoadInt(S);
+  f->k = luaM_newvector(S->L, n, TValue);
+  f->sizek = n;
+  for (i = 0; i < n; i++)
+    setnilvalue(&f->k[i]);
+  for (i = 0; i < n; i++) {
+    TValue *o = &f->k[i];
+    int t = LoadByte(S);
+    switch (t) {
+    case LUA_TNIL:
+      setnilvalue(o);
+      break;
+    case LUA_TBOOLEAN:
+      setbvalue(o, LoadByte(S));
+      break;
+    case LUA_TNUMFLT:
+      setfltvalue(o, LoadNumber(S));
+      break;
+    case LUA_TNUMINT:
+      setivalue(o, LoadInteger(S));
+      break;
+    case LUA_TSHRSTR:
+    case LUA_TLNGSTR:
+      setsvalue2n(S->L, o, LoadString(S));
+      break;
+    default:
+      lua_assert(0);
+    }
+  }
+}
+
+
+static void LoadProtos (LoadState *S, Proto *f) {
+  int i;
+  int n = LoadInt(S);
+  f->p = luaM_newvector(S->L, n, Proto *);
+  f->sizep = n;
+  for (i = 0; i < n; i++)
+    f->p[i] = NULL;
+  for (i = 0; i < n; i++) {
+    f->p[i] = luaF_newproto(S->L);
+    LoadFunction(S, f->p[i], f->source);
+  }
+}
+
+
+static void LoadUpvalues (LoadState *S, Proto *f) {
+  int i, n;
+  n = LoadInt(S);
+  f->upvalues = luaM_newvector(S->L, n, Upvaldesc);
+  f->sizeupvalues = n;
+  for (i = 0; i < n; i++)
+    f->upvalues[i].name = NULL;
+  for (i = 0; i < n; i++) {
+    f->upvalues[i].instack = LoadByte(S);
+    f->upvalues[i].idx = LoadByte(S);
+  }
+}
+
+
+static void LoadDebug (LoadState *S, Proto *f) {
+  int i, n;
+  n = LoadInt(S);
+  f->lineinfo = luaM_newvector(S->L, n, int);
+  f->sizelineinfo = n;
+  LoadVector(S, f->lineinfo, n);
+  n = LoadInt(S);
+  f->locvars = luaM_newvector(S->L, n, LocVar);
+  f->sizelocvars = n;
+  for (i = 0; i < n; i++)
+    f->locvars[i].varname = NULL;
+  for (i = 0; i < n; i++) {
+    f->locvars[i].varname = LoadString(S);
+    f->locvars[i].startpc = LoadInt(S);
+    f->locvars[i].endpc = LoadInt(S);
+  }
+  n = LoadInt(S);
+  for (i = 0; i < n; i++)
+    f->upvalues[i].name = LoadString(S);
+}
+
+
+static void LoadFunction (LoadState *S, Proto *f, TString *psource) {
+  f->source = LoadString(S);
+  if (f->source == NULL)  /* no source in dump? */
+    f->source = psource;  /* reuse parent's source */
+  f->linedefined = LoadInt(S);
+  f->lastlinedefined = LoadInt(S);
+  f->numparams = LoadByte(S);
+  f->is_vararg = LoadByte(S);
+  f->maxstacksize = LoadByte(S);
+  LoadCode(S, f);
+  LoadConstants(S, f);
+  LoadUpvalues(S, f);
+  LoadProtos(S, f);
+  LoadDebug(S, f);
+}
+
+
+static void checkliteral (LoadState *S, const char *s, const char *msg) {
+  char buff[sizeof(LUA_SIGNATURE) + sizeof(LUAC_DATA)]; /* larger than both */
+  size_t len = strlen(s);
+  LoadVector(S, buff, len);
+  if (memcmp(s, buff, len) != 0)
+    error(S, msg);
+}
+
+
+static void fchecksize (LoadState *S, size_t size, const char *tname) {
+  if (LoadByte(S) != size)
+    error(S, luaO_pushfstring(S->L, "%s size mismatch in", tname));
+}
+
+
+#define checksize(S,t)	fchecksize(S,sizeof(t),#t)
+
+static void checkHeader (LoadState *S) {
+  checkliteral(S, LUA_SIGNATURE + 1, "not a");  /* 1st char already checked */
+  if (LoadByte(S) != LUAC_VERSION)
+    error(S, "version mismatch in");
+  if (LoadByte(S) != LUAC_FORMAT)
+    error(S, "format mismatch in");
+  checkliteral(S, LUAC_DATA, "corrupted");
+  checksize(S, int);
+  checksize(S, size_t);
+  checksize(S, Instruction);
+  checksize(S, lua_Integer);
+  checksize(S, lua_Number);
+  if (LoadInteger(S) != LUAC_INT)
+    error(S, "endianness mismatch in");
+  if (LoadNumber(S) != LUAC_NUM)
+    error(S, "float format mismatch in");
+}
+
+
+/*
+** load precompiled chunk
+*/
+LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
+  LoadState S;
+  LClosure *cl;
+  if (*name == '@' || *name == '=')
+    S.name = name + 1;
+  else if (*name == LUA_SIGNATURE[0])
+    S.name = "binary string";
+  else
+    S.name = name;
+  S.L = L;
+  S.Z = Z;
+  checkHeader(&S);
+  cl = luaF_newLclosure(L, LoadByte(&S));
+  setclLvalue(L, L->top, cl);
+  luaD_inctop(L);
+  cl->p = luaF_newproto(L);
+  LoadFunction(&S, cl->p, NULL);
+  lua_assert(cl->nupvalues == cl->p->sizeupvalues);
+  luai_verifycode(L, buff, cl->p);
+  return cl;
+}
+
diff --git a/src/lundump.h b/src/lundump.h
new file mode 100644
index 0000000..aa5cc82
--- /dev/null
+++ b/src/lundump.h
@@ -0,0 +1,32 @@
+/*
+** $Id: lundump.h,v 1.45 2015/09/08 15:41:05 roberto Exp $
+** load precompiled Lua chunks
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lundump_h
+#define lundump_h
+
+#include "llimits.h"
+#include "lobject.h"
+#include "lzio.h"
+
+
+/* data to catch conversion errors */
+#define LUAC_DATA	"\x19\x93\r\n\x1a\n"
+
+#define LUAC_INT	0x5678
+#define LUAC_NUM	cast_num(370.5)
+
+#define MYINT(s)	(s[0]-'0')
+#define LUAC_VERSION	(MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR))
+#define LUAC_FORMAT	0	/* this is the official format */
+
+/* load one chunk; from lundump.c */
+LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, const char* name);
+
+/* dump one chunk; from ldump.c */
+LUAI_FUNC int luaU_dump (lua_State* L, const Proto* f, lua_Writer w,
+                         void* data, int strip);
+
+#endif
diff --git a/src/lutf8lib.c b/src/lutf8lib.c
new file mode 100644
index 0000000..9042582
--- /dev/null
+++ b/src/lutf8lib.c
@@ -0,0 +1,256 @@
+/*
+** $Id: lutf8lib.c,v 1.15 2015/03/28 19:16:55 roberto Exp $
+** Standard library for UTF-8 manipulation
+** See Copyright Notice in lua.h
+*/
+
+#define lutf8lib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <assert.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+#define MAXUNICODE	0x10FFFF
+
+#define iscont(p)	((*(p) & 0xC0) == 0x80)
+
+
+/* from strlib */
+/* translate a relative string position: negative means back from end */
+static lua_Integer u_posrelat (lua_Integer pos, size_t len) {
+  if (pos >= 0) return pos;
+  else if (0u - (size_t)pos > len) return 0;
+  else return (lua_Integer)len + pos + 1;
+}
+
+
+/*
+** Decode one UTF-8 sequence, returning NULL if byte sequence is invalid.
+*/
+static const char *utf8_decode (const char *o, int *val) {
+  static const unsigned int limits[] = {0xFF, 0x7F, 0x7FF, 0xFFFF};
+  const unsigned char *s = (const unsigned char *)o;
+  unsigned int c = s[0];
+  unsigned int res = 0;  /* final result */
+  if (c < 0x80)  /* ascii? */
+    res = c;
+  else {
+    int count = 0;  /* to count number of continuation bytes */
+    while (c & 0x40) {  /* still have continuation bytes? */
+      int cc = s[++count];  /* read next byte */
+      if ((cc & 0xC0) != 0x80)  /* not a continuation byte? */
+        return NULL;  /* invalid byte sequence */
+      res = (res << 6) | (cc & 0x3F);  /* add lower 6 bits from cont. byte */
+      c <<= 1;  /* to test next bit */
+    }
+    res |= ((c & 0x7F) << (count * 5));  /* add first byte */
+    if (count > 3 || res > MAXUNICODE || res <= limits[count])
+      return NULL;  /* invalid byte sequence */
+    s += count;  /* skip continuation bytes read */
+  }
+  if (val) *val = res;
+  return (const char *)s + 1;  /* +1 to include first byte */
+}
+
+
+/*
+** utf8len(s [, i [, j]]) --> number of characters that start in the
+** range [i,j], or nil + current position if 's' is not well formed in
+** that interval
+*/
+static int utflen (lua_State *L) {
+  int n = 0;
+  size_t len;
+  const char *s = luaL_checklstring(L, 1, &len);
+  lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
+  lua_Integer posj = u_posrelat(luaL_optinteger(L, 3, -1), len);
+  luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,
+                   "initial position out of string");
+  luaL_argcheck(L, --posj < (lua_Integer)len, 3,
+                   "final position out of string");
+  while (posi <= posj) {
+    const char *s1 = utf8_decode(s + posi, NULL);
+    if (s1 == NULL) {  /* conversion error? */
+      lua_pushnil(L);  /* return nil ... */
+      lua_pushinteger(L, posi + 1);  /* ... and current position */
+      return 2;
+    }
+    posi = s1 - s;
+    n++;
+  }
+  lua_pushinteger(L, n);
+  return 1;
+}
+
+
+/*
+** codepoint(s, [i, [j]])  -> returns codepoints for all characters
+** that start in the range [i,j]
+*/
+static int codepoint (lua_State *L) {
+  size_t len;
+  const char *s = luaL_checklstring(L, 1, &len);
+  lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
+  lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len);
+  int n;
+  const char *se;
+  luaL_argcheck(L, posi >= 1, 2, "out of range");
+  luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of range");
+  if (posi > pose) return 0;  /* empty interval; return no values */
+  if (pose - posi >= INT_MAX)  /* (lua_Integer -> int) overflow? */
+    return luaL_error(L, "string slice too long");
+  n = (int)(pose -  posi) + 1;
+  luaL_checkstack(L, n, "string slice too long");
+  n = 0;
+  se = s + pose;
+  for (s += posi - 1; s < se;) {
+    int code;
+    s = utf8_decode(s, &code);
+    if (s == NULL)
+      return luaL_error(L, "invalid UTF-8 code");
+    lua_pushinteger(L, code);
+    n++;
+  }
+  return n;
+}
+
+
+static void pushutfchar (lua_State *L, int arg) {
+  lua_Integer code = luaL_checkinteger(L, arg);
+  luaL_argcheck(L, 0 <= code && code <= MAXUNICODE, arg, "value out of range");
+  lua_pushfstring(L, "%U", (long)code);
+}
+
+
+/*
+** utfchar(n1, n2, ...)  -> char(n1)..char(n2)...
+*/
+static int utfchar (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  if (n == 1)  /* optimize common case of single char */
+    pushutfchar(L, 1);
+  else {
+    int i;
+    luaL_Buffer b;
+    luaL_buffinit(L, &b);
+    for (i = 1; i <= n; i++) {
+      pushutfchar(L, i);
+      luaL_addvalue(&b);
+    }
+    luaL_pushresult(&b);
+  }
+  return 1;
+}
+
+
+/*
+** offset(s, n, [i])  -> index where n-th character counting from
+**   position 'i' starts; 0 means character at 'i'.
+*/
+static int byteoffset (lua_State *L) {
+  size_t len;
+  const char *s = luaL_checklstring(L, 1, &len);
+  lua_Integer n  = luaL_checkinteger(L, 2);
+  lua_Integer posi = (n >= 0) ? 1 : len + 1;
+  posi = u_posrelat(luaL_optinteger(L, 3, posi), len);
+  luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3,
+                   "position out of range");
+  if (n == 0) {
+    /* find beginning of current byte sequence */
+    while (posi > 0 && iscont(s + posi)) posi--;
+  }
+  else {
+    if (iscont(s + posi))
+      luaL_error(L, "initial position is a continuation byte");
+    if (n < 0) {
+       while (n < 0 && posi > 0) {  /* move back */
+         do {  /* find beginning of previous character */
+           posi--;
+         } while (posi > 0 && iscont(s + posi));
+         n++;
+       }
+     }
+     else {
+       n--;  /* do not move for 1st character */
+       while (n > 0 && posi < (lua_Integer)len) {
+         do {  /* find beginning of next character */
+           posi++;
+         } while (iscont(s + posi));  /* (cannot pass final '\0') */
+         n--;
+       }
+     }
+  }
+  if (n == 0)  /* did it find given character? */
+    lua_pushinteger(L, posi + 1);
+  else  /* no such character */
+    lua_pushnil(L);
+  return 1;  
+}
+
+
+static int iter_aux (lua_State *L) {
+  size_t len;
+  const char *s = luaL_checklstring(L, 1, &len);
+  lua_Integer n = lua_tointeger(L, 2) - 1;
+  if (n < 0)  /* first iteration? */
+    n = 0;  /* start from here */
+  else if (n < (lua_Integer)len) {
+    n++;  /* skip current byte */
+    while (iscont(s + n)) n++;  /* and its continuations */
+  }
+  if (n >= (lua_Integer)len)
+    return 0;  /* no more codepoints */
+  else {
+    int code;
+    const char *next = utf8_decode(s + n, &code);
+    if (next == NULL || iscont(next))
+      return luaL_error(L, "invalid UTF-8 code");
+    lua_pushinteger(L, n + 1);
+    lua_pushinteger(L, code);
+    return 2;
+  }
+}
+
+
+static int iter_codes (lua_State *L) {
+  luaL_checkstring(L, 1);
+  lua_pushcfunction(L, iter_aux);
+  lua_pushvalue(L, 1);
+  lua_pushinteger(L, 0);
+  return 3;
+}
+
+
+/* pattern to match a single UTF-8 character */
+#define UTF8PATT	"[\0-\x7F\xC2-\xF4][\x80-\xBF]*"
+
+
+static const luaL_Reg funcs[] = {
+  {"offset", byteoffset},
+  {"codepoint", codepoint},
+  {"char", utfchar},
+  {"len", utflen},
+  {"codes", iter_codes},
+  /* placeholders */
+  {"charpattern", NULL},
+  {NULL, NULL}
+};
+
+
+LUAMOD_API int luaopen_utf8 (lua_State *L) {
+  luaL_newlib(L, funcs);
+  lua_pushlstring(L, UTF8PATT, sizeof(UTF8PATT)/sizeof(char) - 1);
+  lua_setfield(L, -2, "charpattern");
+  return 1;
+}
+
diff --git a/src/lvm.c b/src/lvm.c
new file mode 100644
index 0000000..84ade6b
--- /dev/null
+++ b/src/lvm.c
@@ -0,0 +1,1322 @@
+/*
+** $Id: lvm.c,v 2.268 2016/02/05 19:59:14 roberto Exp $
+** Lua virtual machine
+** See Copyright Notice in lua.h
+*/
+
+#define lvm_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+#include <float.h>
+#include <limits.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lvm.h"
+
+
+/* limit for table tag-method chains (to avoid loops) */
+#define MAXTAGLOOP	2000
+
+
+
+/*
+** 'l_intfitsf' checks whether a given integer can be converted to a
+** float without rounding. Used in comparisons. Left undefined if
+** all integers fit in a float precisely.
+*/
+#if !defined(l_intfitsf)
+
+/* number of bits in the mantissa of a float */
+#define NBM		(l_mathlim(MANT_DIG))
+
+/*
+** Check whether some integers may not fit in a float, that is, whether
+** (maxinteger >> NBM) > 0 (that implies (1 << NBM) <= maxinteger).
+** (The shifts are done in parts to avoid shifting by more than the size
+** of an integer. In a worst case, NBM == 113 for long double and
+** sizeof(integer) == 32.)
+*/
+#if ((((LUA_MAXINTEGER >> (NBM / 4)) >> (NBM / 4)) >> (NBM / 4)) \
+	>> (NBM - (3 * (NBM / 4))))  >  0
+
+#define l_intfitsf(i)  \
+  (-((lua_Integer)1 << NBM) <= (i) && (i) <= ((lua_Integer)1 << NBM))
+
+#endif
+
+#endif
+
+
+
+/*
+** Try to convert a value to a float. The float case is already handled
+** by the macro 'tonumber'.
+*/
+int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
+  TValue v;
+  if (ttisinteger(obj)) {
+    *n = cast_num(ivalue(obj));
+    return 1;
+  }
+  else if (cvt2num(obj) &&  /* string convertible to number? */
+            luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
+    *n = nvalue(&v);  /* convert result of 'luaO_str2num' to a float */
+    return 1;
+  }
+  else
+    return 0;  /* conversion failed */
+}
+
+
+/*
+** try to convert a value to an integer, rounding according to 'mode':
+** mode == 0: accepts only integral values
+** mode == 1: takes the floor of the number
+** mode == 2: takes the ceil of the number
+*/
+int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode) {
+  TValue v;
+ again:
+  if (ttisfloat(obj)) {
+    lua_Number n = fltvalue(obj);
+    lua_Number f = l_floor(n);
+    if (n != f) {  /* not an integral value? */
+      if (mode == 0) return 0;  /* fails if mode demands integral value */
+      else if (mode > 1)  /* needs ceil? */
+        f += 1;  /* convert floor to ceil (remember: n != f) */
+    }
+    return lua_numbertointeger(f, p);
+  }
+  else if (ttisinteger(obj)) {
+    *p = ivalue(obj);
+    return 1;
+  }
+  else if (cvt2num(obj) &&
+            luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
+    obj = &v;
+    goto again;  /* convert result from 'luaO_str2num' to an integer */
+  }
+  return 0;  /* conversion failed */
+}
+
+
+/*
+** Try to convert a 'for' limit to an integer, preserving the
+** semantics of the loop.
+** (The following explanation assumes a non-negative step; it is valid
+** for negative steps mutatis mutandis.)
+** If the limit can be converted to an integer, rounding down, that is
+** it.
+** Otherwise, check whether the limit can be converted to a number.  If
+** the number is too large, it is OK to set the limit as LUA_MAXINTEGER,
+** which means no limit.  If the number is too negative, the loop
+** should not run, because any initial integer value is larger than the
+** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects
+** the extreme case when the initial value is LUA_MININTEGER, in which
+** case the LUA_MININTEGER limit would still run the loop once.
+*/
+static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
+                     int *stopnow) {
+  *stopnow = 0;  /* usually, let loops run */
+  if (!luaV_tointeger(obj, p, (step < 0 ? 2 : 1))) {  /* not fit in integer? */
+    lua_Number n;  /* try to convert to float */
+    if (!tonumber(obj, &n)) /* cannot convert to float? */
+      return 0;  /* not a number */
+    if (luai_numlt(0, n)) {  /* if true, float is larger than max integer */
+      *p = LUA_MAXINTEGER;
+      if (step < 0) *stopnow = 1;
+    }
+    else {  /* float is smaller than min integer */
+      *p = LUA_MININTEGER;
+      if (step >= 0) *stopnow = 1;
+    }
+  }
+  return 1;
+}
+
+
+/*
+** Finish the table access 'val = t[key]'.
+** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to
+** t[k] entry (which must be nil).
+*/
+void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
+                      const TValue *slot) {
+  int loop;  /* counter to avoid infinite loops */
+  const TValue *tm;  /* metamethod */
+  for (loop = 0; loop < MAXTAGLOOP; loop++) {
+    if (slot == NULL) {  /* 't' is not a table? */
+      lua_assert(!ttistable(t));
+      tm = luaT_gettmbyobj(L, t, TM_INDEX);
+      if (ttisnil(tm))
+        luaG_typeerror(L, t, "index");  /* no metamethod */
+      /* else will try the metamethod */
+    }
+    else {  /* 't' is a table */
+      lua_assert(ttisnil(slot));
+      tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);  /* table's metamethod */
+      if (tm == NULL) {  /* no metamethod? */
+        setnilvalue(val);  /* result is nil */
+        return;
+      }
+      /* else will try the metamethod */
+    }
+    if (ttisfunction(tm)) {  /* is metamethod a function? */
+      luaT_callTM(L, tm, t, key, val, 1);  /* call it */
+      return;
+    }
+    t = tm;  /* else try to access 'tm[key]' */
+    if (luaV_fastget(L,t,key,slot,luaH_get)) {  /* fast track? */
+      setobj2s(L, val, slot);  /* done */
+      return;
+    }
+    /* else repeat (tail call 'luaV_finishget') */
+  }
+  luaG_runerror(L, "'__index' chain too long; possible loop");
+}
+
+
+/*
+** Finish a table assignment 't[key] = val'.
+** If 'slot' is NULL, 't' is not a table.  Otherwise, 'slot' points
+** to the entry 't[key]', or to 'luaO_nilobject' if there is no such
+** entry.  (The value at 'slot' must be nil, otherwise 'luaV_fastset'
+** would have done the job.)
+*/
+void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
+                     StkId val, const TValue *slot) {
+  int loop;  /* counter to avoid infinite loops */
+  for (loop = 0; loop < MAXTAGLOOP; loop++) {
+    const TValue *tm;  /* '__newindex' metamethod */
+    if (slot != NULL) {  /* is 't' a table? */
+      Table *h = hvalue(t);  /* save 't' table */
+      lua_assert(ttisnil(slot));  /* old value must be nil */
+      tm = fasttm(L, h->metatable, TM_NEWINDEX);  /* get metamethod */
+      if (tm == NULL) {  /* no metamethod? */
+        if (slot == luaO_nilobject)  /* no previous entry? */
+          slot = luaH_newkey(L, h, key);  /* create one */
+        /* no metamethod and (now) there is an entry with given key */
+        setobj2t(L, cast(TValue *, slot), val);  /* set its new value */
+        invalidateTMcache(h);
+        luaC_barrierback(L, h, val);
+        return;
+      }
+      /* else will try the metamethod */
+    }
+    else {  /* not a table; check metamethod */
+      if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
+        luaG_typeerror(L, t, "index");
+    }
+    /* try the metamethod */
+    if (ttisfunction(tm)) {
+      luaT_callTM(L, tm, t, key, val, 0);
+      return;
+    }
+    t = tm;  /* else repeat assignment over 'tm' */
+    if (luaV_fastset(L, t, key, slot, luaH_get, val))
+      return;  /* done */
+    /* else loop */
+  }
+  luaG_runerror(L, "'__newindex' chain too long; possible loop");
+}
+
+
+/*
+** Compare two strings 'ls' x 'rs', returning an integer smaller-equal-
+** -larger than zero if 'ls' is smaller-equal-larger than 'rs'.
+** The code is a little tricky because it allows '\0' in the strings
+** and it uses 'strcoll' (to respect locales) for each segments
+** of the strings.
+*/
+static int l_strcmp (const TString *ls, const TString *rs) {
+  const char *l = getstr(ls);
+  size_t ll = tsslen(ls);
+  const char *r = getstr(rs);
+  size_t lr = tsslen(rs);
+  for (;;) {  /* for each segment */
+    int temp = strcoll(l, r);
+    if (temp != 0)  /* not equal? */
+      return temp;  /* done */
+    else {  /* strings are equal up to a '\0' */
+      size_t len = strlen(l);  /* index of first '\0' in both strings */
+      if (len == lr)  /* 'rs' is finished? */
+        return (len == ll) ? 0 : 1;  /* check 'ls' */
+      else if (len == ll)  /* 'ls' is finished? */
+        return -1;  /* 'ls' is smaller than 'rs' ('rs' is not finished) */
+      /* both strings longer than 'len'; go on comparing after the '\0' */
+      len++;
+      l += len; ll -= len; r += len; lr -= len;
+    }
+  }
+}
+
+
+/*
+** Check whether integer 'i' is less than float 'f'. If 'i' has an
+** exact representation as a float ('l_intfitsf'), compare numbers as
+** floats. Otherwise, if 'f' is outside the range for integers, result
+** is trivial. Otherwise, compare them as integers. (When 'i' has no
+** float representation, either 'f' is "far away" from 'i' or 'f' has
+** no precision left for a fractional part; either way, how 'f' is
+** truncated is irrelevant.) When 'f' is NaN, comparisons must result
+** in false.
+*/
+static int LTintfloat (lua_Integer i, lua_Number f) {
+#if defined(l_intfitsf)
+  if (!l_intfitsf(i)) {
+    if (f >= -cast_num(LUA_MININTEGER))  /* -minint == maxint + 1 */
+      return 1;  /* f >= maxint + 1 > i */
+    else if (f > cast_num(LUA_MININTEGER))  /* minint < f <= maxint ? */
+      return (i < cast(lua_Integer, f));  /* compare them as integers */
+    else  /* f <= minint <= i (or 'f' is NaN)  -->  not(i < f) */
+      return 0;
+  }
+#endif
+  return luai_numlt(cast_num(i), f);  /* compare them as floats */
+}
+
+
+/*
+** Check whether integer 'i' is less than or equal to float 'f'.
+** See comments on previous function.
+*/
+static int LEintfloat (lua_Integer i, lua_Number f) {
+#if defined(l_intfitsf)
+  if (!l_intfitsf(i)) {
+    if (f >= -cast_num(LUA_MININTEGER))  /* -minint == maxint + 1 */
+      return 1;  /* f >= maxint + 1 > i */
+    else if (f >= cast_num(LUA_MININTEGER))  /* minint <= f <= maxint ? */
+      return (i <= cast(lua_Integer, f));  /* compare them as integers */
+    else  /* f < minint <= i (or 'f' is NaN)  -->  not(i <= f) */
+      return 0;
+  }
+#endif
+  return luai_numle(cast_num(i), f);  /* compare them as floats */
+}
+
+
+/*
+** Return 'l < r', for numbers.
+*/
+static int LTnum (const TValue *l, const TValue *r) {
+  if (ttisinteger(l)) {
+    lua_Integer li = ivalue(l);
+    if (ttisinteger(r))
+      return li < ivalue(r);  /* both are integers */
+    else  /* 'l' is int and 'r' is float */
+      return LTintfloat(li, fltvalue(r));  /* l < r ? */
+  }
+  else {
+    lua_Number lf = fltvalue(l);  /* 'l' must be float */
+    if (ttisfloat(r))
+      return luai_numlt(lf, fltvalue(r));  /* both are float */
+    else if (luai_numisnan(lf))  /* 'r' is int and 'l' is float */
+      return 0;  /* NaN < i is always false */
+    else  /* without NaN, (l < r)  <-->  not(r <= l) */
+      return !LEintfloat(ivalue(r), lf);  /* not (r <= l) ? */
+  }
+}
+
+
+/*
+** Return 'l <= r', for numbers.
+*/
+static int LEnum (const TValue *l, const TValue *r) {
+  if (ttisinteger(l)) {
+    lua_Integer li = ivalue(l);
+    if (ttisinteger(r))
+      return li <= ivalue(r);  /* both are integers */
+    else  /* 'l' is int and 'r' is float */
+      return LEintfloat(li, fltvalue(r));  /* l <= r ? */
+  }
+  else {
+    lua_Number lf = fltvalue(l);  /* 'l' must be float */
+    if (ttisfloat(r))
+      return luai_numle(lf, fltvalue(r));  /* both are float */
+    else if (luai_numisnan(lf))  /* 'r' is int and 'l' is float */
+      return 0;  /*  NaN <= i is always false */
+    else  /* without NaN, (l <= r)  <-->  not(r < l) */
+      return !LTintfloat(ivalue(r), lf);  /* not (r < l) ? */
+  }
+}
+
+
+/*
+** Main operation less than; return 'l < r'.
+*/
+int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
+  int res;
+  if (ttisnumber(l) && ttisnumber(r))  /* both operands are numbers? */
+    return LTnum(l, r);
+  else if (ttisstring(l) && ttisstring(r))  /* both are strings? */
+    return l_strcmp(tsvalue(l), tsvalue(r)) < 0;
+  else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0)  /* no metamethod? */
+    luaG_ordererror(L, l, r);  /* error */
+  return res;
+}
+
+
+/*
+** Main operation less than or equal to; return 'l <= r'. If it needs
+** a metamethod and there is no '__le', try '__lt', based on
+** l <= r iff !(r < l) (assuming a total order). If the metamethod
+** yields during this substitution, the continuation has to know
+** about it (to negate the result of r<l); bit CIST_LEQ in the call
+** status keeps that information.
+*/
+int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
+  int res;
+  if (ttisnumber(l) && ttisnumber(r))  /* both operands are numbers? */
+    return LEnum(l, r);
+  else if (ttisstring(l) && ttisstring(r))  /* both are strings? */
+    return l_strcmp(tsvalue(l), tsvalue(r)) <= 0;
+  else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0)  /* try 'le' */
+    return res;
+  else {  /* try 'lt': */
+    L->ci->callstatus |= CIST_LEQ;  /* mark it is doing 'lt' for 'le' */
+    res = luaT_callorderTM(L, r, l, TM_LT);
+    L->ci->callstatus ^= CIST_LEQ;  /* clear mark */
+    if (res < 0)
+      luaG_ordererror(L, l, r);
+    return !res;  /* result is negated */
+  }
+}
+
+
+/*
+** Main operation for equality of Lua values; return 't1 == t2'.
+** L == NULL means raw equality (no metamethods)
+*/
+int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
+  const TValue *tm;
+  if (ttype(t1) != ttype(t2)) {  /* not the same variant? */
+    if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER)
+      return 0;  /* only numbers can be equal with different variants */
+    else {  /* two numbers with different variants */
+      lua_Integer i1, i2;  /* compare them as integers */
+      return (tointeger(t1, &i1) && tointeger(t2, &i2) && i1 == i2);
+    }
+  }
+  /* values have same type and same variant */
+  switch (ttype(t1)) {
+    case LUA_TNIL: return 1;
+    case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2));
+    case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2));
+    case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
+    case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
+    case LUA_TLCF: return fvalue(t1) == fvalue(t2);
+    case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2));
+    case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2));
+    case LUA_TUSERDATA: {
+      if (uvalue(t1) == uvalue(t2)) return 1;
+      else if (L == NULL) return 0;
+      tm = fasttm(L, uvalue(t1)->metatable, TM_EQ);
+      if (tm == NULL)
+        tm = fasttm(L, uvalue(t2)->metatable, TM_EQ);
+      break;  /* will try TM */
+    }
+    case LUA_TTABLE: {
+      if (hvalue(t1) == hvalue(t2)) return 1;
+      else if (L == NULL) return 0;
+      tm = fasttm(L, hvalue(t1)->metatable, TM_EQ);
+      if (tm == NULL)
+        tm = fasttm(L, hvalue(t2)->metatable, TM_EQ);
+      break;  /* will try TM */
+    }
+    default:
+      return gcvalue(t1) == gcvalue(t2);
+  }
+  if (tm == NULL)  /* no TM? */
+    return 0;  /* objects are different */
+  luaT_callTM(L, tm, t1, t2, L->top, 1);  /* call TM */
+  return !l_isfalse(L->top);
+}
+
+
+/* macro used by 'luaV_concat' to ensure that element at 'o' is a string */
+#define tostring(L,o)  \
+	(ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1)))
+
+#define isemptystr(o)	(ttisshrstring(o) && tsvalue(o)->shrlen == 0)
+
+/* copy strings in stack from top - n up to top - 1 to buffer */
+static void copy2buff (StkId top, int n, char *buff) {
+  size_t tl = 0;  /* size already copied */
+  do {
+    size_t l = vslen(top - n);  /* length of string being copied */
+    memcpy(buff + tl, svalue(top - n), l * sizeof(char));
+    tl += l;
+  } while (--n > 0);
+}
+
+
+/*
+** Main operation for concatenation: concat 'total' values in the stack,
+** from 'L->top - total' up to 'L->top - 1'.
+*/
+void luaV_concat (lua_State *L, int total) {
+  lua_assert(total >= 2);
+  do {
+    StkId top = L->top;
+    int n = 2;  /* number of elements handled in this pass (at least 2) */
+    if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1))
+      luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT);
+    else if (isemptystr(top - 1))  /* second operand is empty? */
+      cast_void(tostring(L, top - 2));  /* result is first operand */
+    else if (isemptystr(top - 2)) {  /* first operand is an empty string? */
+      setobjs2s(L, top - 2, top - 1);  /* result is second op. */
+    }
+    else {
+      /* at least two non-empty string values; get as many as possible */
+      size_t tl = vslen(top - 1);
+      TString *ts;
+      /* collect total length and number of strings */
+      for (n = 1; n < total && tostring(L, top - n - 1); n++) {
+        size_t l = vslen(top - n - 1);
+        if (l >= (MAX_SIZE/sizeof(char)) - tl)
+          luaG_runerror(L, "string length overflow");
+        tl += l;
+      }
+      if (tl <= LUAI_MAXSHORTLEN) {  /* is result a short string? */
+        char buff[LUAI_MAXSHORTLEN];
+        copy2buff(top, n, buff);  /* copy strings to buffer */
+        ts = luaS_newlstr(L, buff, tl);
+      }
+      else {  /* long string; copy strings directly to final result */
+        ts = luaS_createlngstrobj(L, tl);
+        copy2buff(top, n, getstr(ts));
+      }
+      setsvalue2s(L, top - n, ts);  /* create result */
+    }
+    total -= n-1;  /* got 'n' strings to create 1 new */
+    L->top -= n-1;  /* popped 'n' strings and pushed one */
+  } while (total > 1);  /* repeat until only 1 result left */
+}
+
+
+/*
+** Main operation 'ra' = #rb'.
+*/
+void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
+  const TValue *tm;
+  switch (ttype(rb)) {
+    case LUA_TTABLE: {
+      Table *h = hvalue(rb);
+      tm = fasttm(L, h->metatable, TM_LEN);
+      if (tm) break;  /* metamethod? break switch to call it */
+      setivalue(ra, luaH_getn(h));  /* else primitive len */
+      return;
+    }
+    case LUA_TSHRSTR: {
+      setivalue(ra, tsvalue(rb)->shrlen);
+      return;
+    }
+    case LUA_TLNGSTR: {
+      setivalue(ra, tsvalue(rb)->u.lnglen);
+      return;
+    }
+    default: {  /* try metamethod */
+      tm = luaT_gettmbyobj(L, rb, TM_LEN);
+      if (ttisnil(tm))  /* no metamethod? */
+        luaG_typeerror(L, rb, "get length of");
+      break;
+    }
+  }
+  luaT_callTM(L, tm, rb, rb, ra, 1);
+}
+
+
+/*
+** Integer division; return 'm // n', that is, floor(m/n).
+** C division truncates its result (rounds towards zero).
+** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer,
+** otherwise 'floor(q) == trunc(q) - 1'.
+*/
+lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) {
+  if (l_castS2U(n) + 1u <= 1u) {  /* special cases: -1 or 0 */
+    if (n == 0)
+      luaG_runerror(L, "attempt to divide by zero");
+    return intop(-, 0, m);   /* n==-1; avoid overflow with 0x80000...//-1 */
+  }
+  else {
+    lua_Integer q = m / n;  /* perform C division */
+    if ((m ^ n) < 0 && m % n != 0)  /* 'm/n' would be negative non-integer? */
+      q -= 1;  /* correct result for different rounding */
+    return q;
+  }
+}
+
+
+/*
+** Integer modulus; return 'm % n'. (Assume that C '%' with
+** negative operands follows C99 behavior. See previous comment
+** about luaV_div.)
+*/
+lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
+  if (l_castS2U(n) + 1u <= 1u) {  /* special cases: -1 or 0 */
+    if (n == 0)
+      luaG_runerror(L, "attempt to perform 'n%%0'");
+    return 0;   /* m % -1 == 0; avoid overflow with 0x80000...%-1 */
+  }
+  else {
+    lua_Integer r = m % n;
+    if (r != 0 && (m ^ n) < 0)  /* 'm/n' would be non-integer negative? */
+      r += n;  /* correct result for different rounding */
+    return r;
+  }
+}
+
+
+/* number of bits in an integer */
+#define NBITS	cast_int(sizeof(lua_Integer) * CHAR_BIT)
+
+/*
+** Shift left operation. (Shift right just negates 'y'.)
+*/
+lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) {
+  if (y < 0) {  /* shift right? */
+    if (y <= -NBITS) return 0;
+    else return intop(>>, x, -y);
+  }
+  else {  /* shift left */
+    if (y >= NBITS) return 0;
+    else return intop(<<, x, y);
+  }
+}
+
+
+/*
+** check whether cached closure in prototype 'p' may be reused, that is,
+** whether there is a cached closure with the same upvalues needed by
+** new closure to be created.
+*/
+static LClosure *getcached (Proto *p, UpVal **encup, StkId base) {
+  LClosure *c = p->cache;
+  if (c != NULL) {  /* is there a cached closure? */
+    int nup = p->sizeupvalues;
+    Upvaldesc *uv = p->upvalues;
+    int i;
+    for (i = 0; i < nup; i++) {  /* check whether it has right upvalues */
+      TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v;
+      if (c->upvals[i]->v != v)
+        return NULL;  /* wrong upvalue; cannot reuse closure */
+    }
+  }
+  return c;  /* return cached closure (or NULL if no cached closure) */
+}
+
+
+/*
+** create a new Lua closure, push it in the stack, and initialize
+** its upvalues. Note that the closure is not cached if prototype is
+** already black (which means that 'cache' was already cleared by the
+** GC).
+*/
+static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
+                         StkId ra) {
+  int nup = p->sizeupvalues;
+  Upvaldesc *uv = p->upvalues;
+  int i;
+  LClosure *ncl = luaF_newLclosure(L, nup);
+  ncl->p = p;
+  setclLvalue(L, ra, ncl);  /* anchor new closure in stack */
+  for (i = 0; i < nup; i++) {  /* fill in its upvalues */
+    if (uv[i].instack)  /* upvalue refers to local variable? */
+      ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx);
+    else  /* get upvalue from enclosing function */
+      ncl->upvals[i] = encup[uv[i].idx];
+    ncl->upvals[i]->refcount++;
+    /* new closure is white, so we do not need a barrier here */
+  }
+  if (!isblack(p))  /* cache will not break GC invariant? */
+    p->cache = ncl;  /* save it on cache for reuse */
+}
+
+
+/*
+** finish execution of an opcode interrupted by an yield
+*/
+void luaV_finishOp (lua_State *L) {
+  CallInfo *ci = L->ci;
+  StkId base = ci->u.l.base;
+  Instruction inst = *(ci->u.l.savedpc - 1);  /* interrupted instruction */
+  OpCode op = GET_OPCODE(inst);
+  switch (op) {  /* finish its execution */
+    case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV: case OP_IDIV:
+    case OP_BAND: case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR:
+    case OP_MOD: case OP_POW:
+    case OP_UNM: case OP_BNOT: case OP_LEN:
+    case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: {
+      setobjs2s(L, base + GETARG_A(inst), --L->top);
+      break;
+    }
+    case OP_LE: case OP_LT: case OP_EQ: {
+      int res = !l_isfalse(L->top - 1);
+      L->top--;
+      if (ci->callstatus & CIST_LEQ) {  /* "<=" using "<" instead? */
+        lua_assert(op == OP_LE);
+        ci->callstatus ^= CIST_LEQ;  /* clear mark */
+        res = !res;  /* negate result */
+      }
+      lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
+      if (res != GETARG_A(inst))  /* condition failed? */
+        ci->u.l.savedpc++;  /* skip jump instruction */
+      break;
+    }
+    case OP_CONCAT: {
+      StkId top = L->top - 1;  /* top when 'luaT_trybinTM' was called */
+      int b = GETARG_B(inst);      /* first element to concatenate */
+      int total = cast_int(top - 1 - (base + b));  /* yet to concatenate */
+      setobj2s(L, top - 2, top);  /* put TM result in proper position */
+      if (total > 1) {  /* are there elements to concat? */
+        L->top = top - 1;  /* top is one after last element (at top-2) */
+        luaV_concat(L, total);  /* concat them (may yield again) */
+      }
+      /* move final result to final position */
+      setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1);
+      L->top = ci->top;  /* restore top */
+      break;
+    }
+    case OP_TFORCALL: {
+      lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP);
+      L->top = ci->top;  /* correct top */
+      break;
+    }
+    case OP_CALL: {
+      if (GETARG_C(inst) - 1 >= 0)  /* nresults >= 0? */
+        L->top = ci->top;  /* adjust results */
+      break;
+    }
+    case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE:
+      break;
+    default: lua_assert(0);
+  }
+}
+
+
+
+
+/*
+** {==================================================================
+** Function 'luaV_execute': main interpreter loop
+** ===================================================================
+*/
+
+
+/*
+** some macros for common tasks in 'luaV_execute'
+*/
+
+
+#define RA(i)	(base+GETARG_A(i))
+#define RB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
+#define RC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
+#define RKB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
+	ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
+#define RKC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
+	ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
+
+
+/* execute a jump instruction */
+#define dojump(ci,i,e) \
+  { int a = GETARG_A(i); \
+    if (a != 0) luaF_close(L, ci->u.l.base + a - 1); \
+    ci->u.l.savedpc += GETARG_sBx(i) + e; }
+
+/* for test instructions, execute the jump instruction that follows it */
+#define donextjump(ci)	{ i = *ci->u.l.savedpc; dojump(ci, i, 1); }
+
+
+#define Protect(x)	{ {x;}; base = ci->u.l.base; }
+
+#define checkGC(L,c)  \
+	{ luaC_condGC(L, L->top = (c),  /* limit of live values */ \
+                         Protect(L->top = ci->top));  /* restore top */ \
+           luai_threadyield(L); }
+
+
+/* fetch an instruction and prepare its execution */
+#define vmfetch()	{ \
+  i = *(ci->u.l.savedpc++); \
+  if (L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) \
+    Protect(luaG_traceexec(L)); \
+  ra = RA(i); /* WARNING: any stack reallocation invalidates 'ra' */ \
+  lua_assert(base == ci->u.l.base); \
+  lua_assert(base <= L->top && L->top < L->stack + L->stacksize); \
+}
+
+#define vmdispatch(o)	switch(o)
+#define vmcase(l)	case l:
+#define vmbreak		break
+
+
+/*
+** copy of 'luaV_gettable', but protecting the call to potential
+** metamethod (which can reallocate the stack)
+*/
+#define gettableProtected(L,t,k,v)  { const TValue *slot; \
+  if (luaV_fastget(L,t,k,slot,luaH_get)) { setobj2s(L, v, slot); } \
+  else Protect(luaV_finishget(L,t,k,v,slot)); }
+
+
+/* same for 'luaV_settable' */
+#define settableProtected(L,t,k,v) { const TValue *slot; \
+  if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
+    Protect(luaV_finishset(L,t,k,v,slot)); }
+
+
+
+void luaV_execute (lua_State *L) {
+  CallInfo *ci = L->ci;
+  LClosure *cl;
+  TValue *k;
+  StkId base;
+  ci->callstatus |= CIST_FRESH;  /* fresh invocation of 'luaV_execute" */
+ newframe:  /* reentry point when frame changes (call/return) */
+  lua_assert(ci == L->ci);
+  cl = clLvalue(ci->func);  /* local reference to function's closure */
+  k = cl->p->k;  /* local reference to function's constant table */
+  base = ci->u.l.base;  /* local copy of function's base */
+  /* main loop of interpreter */
+  for (;;) {
+    Instruction i;
+    StkId ra;
+    vmfetch();
+    vmdispatch (GET_OPCODE(i)) {
+      vmcase(OP_MOVE) {
+        setobjs2s(L, ra, RB(i));
+        vmbreak;
+      }
+      vmcase(OP_LOADK) {
+        TValue *rb = k + GETARG_Bx(i);
+        setobj2s(L, ra, rb);
+        vmbreak;
+      }
+      vmcase(OP_LOADKX) {
+        TValue *rb;
+        lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
+        rb = k + GETARG_Ax(*ci->u.l.savedpc++);
+        setobj2s(L, ra, rb);
+        vmbreak;
+      }
+      vmcase(OP_LOADBOOL) {
+        setbvalue(ra, GETARG_B(i));
+        if (GETARG_C(i)) ci->u.l.savedpc++;  /* skip next instruction (if C) */
+        vmbreak;
+      }
+      vmcase(OP_LOADNIL) {
+        int b = GETARG_B(i);
+        do {
+          setnilvalue(ra++);
+        } while (b--);
+        vmbreak;
+      }
+      vmcase(OP_GETUPVAL) {
+        int b = GETARG_B(i);
+        setobj2s(L, ra, cl->upvals[b]->v);
+        vmbreak;
+      }
+      vmcase(OP_GETTABUP) {
+        TValue *upval = cl->upvals[GETARG_B(i)]->v;
+        TValue *rc = RKC(i);
+        gettableProtected(L, upval, rc, ra);
+        vmbreak;
+      }
+      vmcase(OP_GETTABLE) {
+        StkId rb = RB(i);
+        TValue *rc = RKC(i);
+        gettableProtected(L, rb, rc, ra);
+        vmbreak;
+      }
+      vmcase(OP_SETTABUP) {
+        TValue *upval = cl->upvals[GETARG_A(i)]->v;
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        settableProtected(L, upval, rb, rc);
+        vmbreak;
+      }
+      vmcase(OP_SETUPVAL) {
+        UpVal *uv = cl->upvals[GETARG_B(i)];
+        setobj(L, uv->v, ra);
+        luaC_upvalbarrier(L, uv);
+        vmbreak;
+      }
+      vmcase(OP_SETTABLE) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        settableProtected(L, ra, rb, rc);
+        vmbreak;
+      }
+      vmcase(OP_NEWTABLE) {
+        int b = GETARG_B(i);
+        int c = GETARG_C(i);
+        Table *t = luaH_new(L);
+        sethvalue(L, ra, t);
+        if (b != 0 || c != 0)
+          luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c));
+        checkGC(L, ra + 1);
+        vmbreak;
+      }
+      vmcase(OP_SELF) {
+        const TValue *aux;
+        StkId rb = RB(i);
+        TValue *rc = RKC(i);
+        TString *key = tsvalue(rc);  /* key must be a string */
+        setobjs2s(L, ra + 1, rb);
+        if (luaV_fastget(L, rb, key, aux, luaH_getstr)) {
+          setobj2s(L, ra, aux);
+        }
+        else Protect(luaV_finishget(L, rb, rc, ra, aux));
+        vmbreak;
+      }
+      vmcase(OP_ADD) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (ttisinteger(rb) && ttisinteger(rc)) {
+          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
+          setivalue(ra, intop(+, ib, ic));
+        }
+        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          setfltvalue(ra, luai_numadd(L, nb, nc));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_ADD)); }
+        vmbreak;
+      }
+      vmcase(OP_SUB) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (ttisinteger(rb) && ttisinteger(rc)) {
+          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
+          setivalue(ra, intop(-, ib, ic));
+        }
+        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          setfltvalue(ra, luai_numsub(L, nb, nc));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SUB)); }
+        vmbreak;
+      }
+      vmcase(OP_MUL) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (ttisinteger(rb) && ttisinteger(rc)) {
+          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
+          setivalue(ra, intop(*, ib, ic));
+        }
+        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          setfltvalue(ra, luai_nummul(L, nb, nc));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MUL)); }
+        vmbreak;
+      }
+      vmcase(OP_DIV) {  /* float division (always with floats) */
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          setfltvalue(ra, luai_numdiv(L, nb, nc));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_DIV)); }
+        vmbreak;
+      }
+      vmcase(OP_BAND) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Integer ib; lua_Integer ic;
+        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
+          setivalue(ra, intop(&, ib, ic));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BAND)); }
+        vmbreak;
+      }
+      vmcase(OP_BOR) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Integer ib; lua_Integer ic;
+        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
+          setivalue(ra, intop(|, ib, ic));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BOR)); }
+        vmbreak;
+      }
+      vmcase(OP_BXOR) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Integer ib; lua_Integer ic;
+        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
+          setivalue(ra, intop(^, ib, ic));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BXOR)); }
+        vmbreak;
+      }
+      vmcase(OP_SHL) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Integer ib; lua_Integer ic;
+        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
+          setivalue(ra, luaV_shiftl(ib, ic));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHL)); }
+        vmbreak;
+      }
+      vmcase(OP_SHR) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Integer ib; lua_Integer ic;
+        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
+          setivalue(ra, luaV_shiftl(ib, -ic));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHR)); }
+        vmbreak;
+      }
+      vmcase(OP_MOD) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (ttisinteger(rb) && ttisinteger(rc)) {
+          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
+          setivalue(ra, luaV_mod(L, ib, ic));
+        }
+        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          lua_Number m;
+          luai_nummod(L, nb, nc, m);
+          setfltvalue(ra, m);
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MOD)); }
+        vmbreak;
+      }
+      vmcase(OP_IDIV) {  /* floor division */
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (ttisinteger(rb) && ttisinteger(rc)) {
+          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
+          setivalue(ra, luaV_div(L, ib, ic));
+        }
+        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          setfltvalue(ra, luai_numidiv(L, nb, nc));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_IDIV)); }
+        vmbreak;
+      }
+      vmcase(OP_POW) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        lua_Number nb; lua_Number nc;
+        if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
+          setfltvalue(ra, luai_numpow(L, nb, nc));
+        }
+        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_POW)); }
+        vmbreak;
+      }
+      vmcase(OP_UNM) {
+        TValue *rb = RB(i);
+        lua_Number nb;
+        if (ttisinteger(rb)) {
+          lua_Integer ib = ivalue(rb);
+          setivalue(ra, intop(-, 0, ib));
+        }
+        else if (tonumber(rb, &nb)) {
+          setfltvalue(ra, luai_numunm(L, nb));
+        }
+        else {
+          Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM));
+        }
+        vmbreak;
+      }
+      vmcase(OP_BNOT) {
+        TValue *rb = RB(i);
+        lua_Integer ib;
+        if (tointeger(rb, &ib)) {
+          setivalue(ra, intop(^, ~l_castS2U(0), ib));
+        }
+        else {
+          Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT));
+        }
+        vmbreak;
+      }
+      vmcase(OP_NOT) {
+        TValue *rb = RB(i);
+        int res = l_isfalse(rb);  /* next assignment may change this value */
+        setbvalue(ra, res);
+        vmbreak;
+      }
+      vmcase(OP_LEN) {
+        Protect(luaV_objlen(L, ra, RB(i)));
+        vmbreak;
+      }
+      vmcase(OP_CONCAT) {
+        int b = GETARG_B(i);
+        int c = GETARG_C(i);
+        StkId rb;
+        L->top = base + c + 1;  /* mark the end of concat operands */
+        Protect(luaV_concat(L, c - b + 1));
+        ra = RA(i);  /* 'luaV_concat' may invoke TMs and move the stack */
+        rb = base + b;
+        setobjs2s(L, ra, rb);
+        checkGC(L, (ra >= rb ? ra + 1 : rb));
+        L->top = ci->top;  /* restore top */
+        vmbreak;
+      }
+      vmcase(OP_JMP) {
+        dojump(ci, i, 0);
+        vmbreak;
+      }
+      vmcase(OP_EQ) {
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        Protect(
+          if (luaV_equalobj(L, rb, rc) != GETARG_A(i))
+            ci->u.l.savedpc++;
+          else
+            donextjump(ci);
+        )
+        vmbreak;
+      }
+      vmcase(OP_LT) {
+        Protect(
+          if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i))
+            ci->u.l.savedpc++;
+          else
+            donextjump(ci);
+        )
+        vmbreak;
+      }
+      vmcase(OP_LE) {
+        Protect(
+          if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i))
+            ci->u.l.savedpc++;
+          else
+            donextjump(ci);
+        )
+        vmbreak;
+      }
+      vmcase(OP_TEST) {
+        if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra))
+            ci->u.l.savedpc++;
+          else
+          donextjump(ci);
+        vmbreak;
+      }
+      vmcase(OP_TESTSET) {
+        TValue *rb = RB(i);
+        if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb))
+          ci->u.l.savedpc++;
+        else {
+          setobjs2s(L, ra, rb);
+          donextjump(ci);
+        }
+        vmbreak;
+      }
+      vmcase(OP_CALL) {
+        int b = GETARG_B(i);
+        int nresults = GETARG_C(i) - 1;
+        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
+        if (luaD_precall(L, ra, nresults)) {  /* C function? */
+          if (nresults >= 0)
+            L->top = ci->top;  /* adjust results */
+          Protect((void)0);  /* update 'base' */
+        }
+        else {  /* Lua function */
+          ci = L->ci;
+          goto newframe;  /* restart luaV_execute over new Lua function */
+        }
+        vmbreak;
+      }
+      vmcase(OP_TAILCALL) {
+        int b = GETARG_B(i);
+        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
+        lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
+        if (luaD_precall(L, ra, LUA_MULTRET)) {  /* C function? */
+          Protect((void)0);  /* update 'base' */
+        }
+        else {
+          /* tail call: put called frame (n) in place of caller one (o) */
+          CallInfo *nci = L->ci;  /* called frame */
+          CallInfo *oci = nci->previous;  /* caller frame */
+          StkId nfunc = nci->func;  /* called function */
+          StkId ofunc = oci->func;  /* caller function */
+          /* last stack slot filled by 'precall' */
+          StkId lim = nci->u.l.base + getproto(nfunc)->numparams;
+          int aux;
+          /* close all upvalues from previous call */
+          if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base);
+          /* move new frame into old one */
+          for (aux = 0; nfunc + aux < lim; aux++)
+            setobjs2s(L, ofunc + aux, nfunc + aux);
+          oci->u.l.base = ofunc + (nci->u.l.base - nfunc);  /* correct base */
+          oci->top = L->top = ofunc + (L->top - nfunc);  /* correct top */
+          oci->u.l.savedpc = nci->u.l.savedpc;
+          oci->callstatus |= CIST_TAIL;  /* function was tail called */
+          ci = L->ci = oci;  /* remove new frame */
+          lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize);
+          goto newframe;  /* restart luaV_execute over new Lua function */
+        }
+        vmbreak;
+      }
+      vmcase(OP_RETURN) {
+        int b = GETARG_B(i);
+        if (cl->p->sizep > 0) luaF_close(L, base);
+        b = luaD_poscall(L, ci, ra, (b != 0 ? b - 1 : cast_int(L->top - ra)));
+        if (ci->callstatus & CIST_FRESH)  /* local 'ci' still from callee */
+          return;  /* external invocation: return */
+        else {  /* invocation via reentry: continue execution */
+          ci = L->ci;
+          if (b) L->top = ci->top;
+          lua_assert(isLua(ci));
+          lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL);
+          goto newframe;  /* restart luaV_execute over new Lua function */
+        }
+      }
+      vmcase(OP_FORLOOP) {
+        if (ttisinteger(ra)) {  /* integer loop? */
+          lua_Integer step = ivalue(ra + 2);
+          lua_Integer idx = intop(+, ivalue(ra), step); /* increment index */
+          lua_Integer limit = ivalue(ra + 1);
+          if ((0 < step) ? (idx <= limit) : (limit <= idx)) {
+            ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
+            chgivalue(ra, idx);  /* update internal index... */
+            setivalue(ra + 3, idx);  /* ...and external index */
+          }
+        }
+        else {  /* floating loop */
+          lua_Number step = fltvalue(ra + 2);
+          lua_Number idx = luai_numadd(L, fltvalue(ra), step); /* inc. index */
+          lua_Number limit = fltvalue(ra + 1);
+          if (luai_numlt(0, step) ? luai_numle(idx, limit)
+                                  : luai_numle(limit, idx)) {
+            ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
+            chgfltvalue(ra, idx);  /* update internal index... */
+            setfltvalue(ra + 3, idx);  /* ...and external index */
+          }
+        }
+        vmbreak;
+      }
+      vmcase(OP_FORPREP) {
+        TValue *init = ra;
+        TValue *plimit = ra + 1;
+        TValue *pstep = ra + 2;
+        lua_Integer ilimit;
+        int stopnow;
+        if (ttisinteger(init) && ttisinteger(pstep) &&
+            forlimit(plimit, &ilimit, ivalue(pstep), &stopnow)) {
+          /* all values are integer */
+          lua_Integer initv = (stopnow ? 0 : ivalue(init));
+          setivalue(plimit, ilimit);
+          setivalue(init, intop(-, initv, ivalue(pstep)));
+        }
+        else {  /* try making all values floats */
+          lua_Number ninit; lua_Number nlimit; lua_Number nstep;
+          if (!tonumber(plimit, &nlimit))
+            luaG_runerror(L, "'for' limit must be a number");
+          setfltvalue(plimit, nlimit);
+          if (!tonumber(pstep, &nstep))
+            luaG_runerror(L, "'for' step must be a number");
+          setfltvalue(pstep, nstep);
+          if (!tonumber(init, &ninit))
+            luaG_runerror(L, "'for' initial value must be a number");
+          setfltvalue(init, luai_numsub(L, ninit, nstep));
+        }
+        ci->u.l.savedpc += GETARG_sBx(i);
+        vmbreak;
+      }
+      vmcase(OP_TFORCALL) {
+        StkId cb = ra + 3;  /* call base */
+        setobjs2s(L, cb+2, ra+2);
+        setobjs2s(L, cb+1, ra+1);
+        setobjs2s(L, cb, ra);
+        L->top = cb + 3;  /* func. + 2 args (state and index) */
+        Protect(luaD_call(L, cb, GETARG_C(i)));
+        L->top = ci->top;
+        i = *(ci->u.l.savedpc++);  /* go to next instruction */
+        ra = RA(i);
+        lua_assert(GET_OPCODE(i) == OP_TFORLOOP);
+        goto l_tforloop;
+      }
+      vmcase(OP_TFORLOOP) {
+        l_tforloop:
+        if (!ttisnil(ra + 1)) {  /* continue loop? */
+          setobjs2s(L, ra, ra + 1);  /* save control variable */
+           ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
+        }
+        vmbreak;
+      }
+      vmcase(OP_SETLIST) {
+        int n = GETARG_B(i);
+        int c = GETARG_C(i);
+        unsigned int last;
+        Table *h;
+        if (n == 0) n = cast_int(L->top - ra) - 1;
+        if (c == 0) {
+          lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
+          c = GETARG_Ax(*ci->u.l.savedpc++);
+        }
+        h = hvalue(ra);
+        last = ((c-1)*LFIELDS_PER_FLUSH) + n;
+        if (last > h->sizearray)  /* needs more space? */
+          luaH_resizearray(L, h, last);  /* preallocate it at once */
+        for (; n > 0; n--) {
+          TValue *val = ra+n;
+          luaH_setint(L, h, last--, val);
+          luaC_barrierback(L, h, val);
+        }
+        L->top = ci->top;  /* correct top (in case of previous open call) */
+        vmbreak;
+      }
+      vmcase(OP_CLOSURE) {
+        Proto *p = cl->p->p[GETARG_Bx(i)];
+        LClosure *ncl = getcached(p, cl->upvals, base);  /* cached closure */
+        if (ncl == NULL)  /* no match? */
+          pushclosure(L, p, cl->upvals, base, ra);  /* create a new one */
+        else
+          setclLvalue(L, ra, ncl);  /* push cashed closure */
+        checkGC(L, ra + 1);
+        vmbreak;
+      }
+      vmcase(OP_VARARG) {
+        int b = GETARG_B(i) - 1;  /* required results */
+        int j;
+        int n = cast_int(base - ci->func) - cl->p->numparams - 1;
+        if (n < 0)  /* less arguments than parameters? */
+          n = 0;  /* no vararg arguments */
+        if (b < 0) {  /* B == 0? */
+          b = n;  /* get all var. arguments */
+          Protect(luaD_checkstack(L, n));
+          ra = RA(i);  /* previous call may change the stack */
+          L->top = ra + n;
+        }
+        for (j = 0; j < b && j < n; j++)
+          setobjs2s(L, ra + j, base - n + j);
+        for (; j < b; j++)  /* complete required results with nil */
+          setnilvalue(ra + j);
+        vmbreak;
+      }
+      vmcase(OP_EXTRAARG) {
+        lua_assert(0);
+        vmbreak;
+      }
+    }
+  }
+}
+
+/* }================================================================== */
+
diff --git a/src/lvm.h b/src/lvm.h
new file mode 100644
index 0000000..bcf52d2
--- /dev/null
+++ b/src/lvm.h
@@ -0,0 +1,113 @@
+/*
+** $Id: lvm.h,v 2.40 2016/01/05 16:07:21 roberto Exp $
+** Lua virtual machine
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lvm_h
+#define lvm_h
+
+
+#include "ldo.h"
+#include "lobject.h"
+#include "ltm.h"
+
+
+#if !defined(LUA_NOCVTN2S)
+#define cvt2str(o)	ttisnumber(o)
+#else
+#define cvt2str(o)	0	/* no conversion from numbers to strings */
+#endif
+
+
+#if !defined(LUA_NOCVTS2N)
+#define cvt2num(o)	ttisstring(o)
+#else
+#define cvt2num(o)	0	/* no conversion from strings to numbers */
+#endif
+
+
+/*
+** You can define LUA_FLOORN2I if you want to convert floats to integers
+** by flooring them (instead of raising an error if they are not
+** integral values)
+*/
+#if !defined(LUA_FLOORN2I)
+#define LUA_FLOORN2I		0
+#endif
+
+
+#define tonumber(o,n) \
+	(ttisfloat(o) ? (*(n) = fltvalue(o), 1) : luaV_tonumber_(o,n))
+
+#define tointeger(o,i) \
+    (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointeger(o,i,LUA_FLOORN2I))
+
+#define intop(op,v1,v2) l_castU2S(l_castS2U(v1) op l_castS2U(v2))
+
+#define luaV_rawequalobj(t1,t2)		luaV_equalobj(NULL,t1,t2)
+
+
+/*
+** fast track for 'gettable': if 't' is a table and 't[k]' is not nil,
+** return 1 with 'slot' pointing to 't[k]' (final result).  Otherwise,
+** return 0 (meaning it will have to check metamethod) with 'slot'
+** pointing to a nil 't[k]' (if 't' is a table) or NULL (otherwise).
+** 'f' is the raw get function to use.
+*/
+#define luaV_fastget(L,t,k,slot,f) \
+  (!ttistable(t)  \
+   ? (slot = NULL, 0)  /* not a table; 'slot' is NULL and result is 0 */  \
+   : (slot = f(hvalue(t), k),  /* else, do raw access */  \
+      !ttisnil(slot)))  /* result not nil? */
+
+/*
+** standard implementation for 'gettable'
+*/
+#define luaV_gettable(L,t,k,v) { const TValue *slot; \
+  if (luaV_fastget(L,t,k,slot,luaH_get)) { setobj2s(L, v, slot); } \
+  else luaV_finishget(L,t,k,v,slot); }
+
+
+/*
+** Fast track for set table. If 't' is a table and 't[k]' is not nil,
+** call GC barrier, do a raw 't[k]=v', and return true; otherwise,
+** return false with 'slot' equal to NULL (if 't' is not a table) or
+** 'nil'. (This is needed by 'luaV_finishget'.) Note that, if the macro
+** returns true, there is no need to 'invalidateTMcache', because the
+** call is not creating a new entry.
+*/
+#define luaV_fastset(L,t,k,slot,f,v) \
+  (!ttistable(t) \
+   ? (slot = NULL, 0) \
+   : (slot = f(hvalue(t), k), \
+     ttisnil(slot) ? 0 \
+     : (luaC_barrierback(L, hvalue(t), v), \
+        setobj2t(L, cast(TValue *,slot), v), \
+        1)))
+
+
+#define luaV_settable(L,t,k,v) { const TValue *slot; \
+  if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
+    luaV_finishset(L,t,k,v,slot); }
+  
+
+
+LUAI_FUNC int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2);
+LUAI_FUNC int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r);
+LUAI_FUNC int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r);
+LUAI_FUNC int luaV_tonumber_ (const TValue *obj, lua_Number *n);
+LUAI_FUNC int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode);
+LUAI_FUNC void luaV_finishget (lua_State *L, const TValue *t, TValue *key,
+                               StkId val, const TValue *slot);
+LUAI_FUNC void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
+                               StkId val, const TValue *slot);
+LUAI_FUNC void luaV_finishOp (lua_State *L);
+LUAI_FUNC void luaV_execute (lua_State *L);
+LUAI_FUNC void luaV_concat (lua_State *L, int total);
+LUAI_FUNC lua_Integer luaV_div (lua_State *L, lua_Integer x, lua_Integer y);
+LUAI_FUNC lua_Integer luaV_mod (lua_State *L, lua_Integer x, lua_Integer y);
+LUAI_FUNC lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y);
+LUAI_FUNC void luaV_objlen (lua_State *L, StkId ra, const TValue *rb);
+
+#endif
diff --git a/src/lzio.c b/src/lzio.c
new file mode 100644
index 0000000..c9e1f49
--- /dev/null
+++ b/src/lzio.c
@@ -0,0 +1,68 @@
+/*
+** $Id: lzio.c,v 1.37 2015/09/08 15:41:05 roberto Exp $
+** Buffered streams
+** See Copyright Notice in lua.h
+*/
+
+#define lzio_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "llimits.h"
+#include "lmem.h"
+#include "lstate.h"
+#include "lzio.h"
+
+
+int luaZ_fill (ZIO *z) {
+  size_t size;
+  lua_State *L = z->L;
+  const char *buff;
+  lua_unlock(L);
+  buff = z->reader(L, z->data, &size);
+  lua_lock(L);
+  if (buff == NULL || size == 0)
+    return EOZ;
+  z->n = size - 1;  /* discount char being returned */
+  z->p = buff;
+  return cast_uchar(*(z->p++));
+}
+
+
+void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
+  z->L = L;
+  z->reader = reader;
+  z->data = data;
+  z->n = 0;
+  z->p = NULL;
+}
+
+
+/* --------------------------------------------------------------- read --- */
+size_t luaZ_read (ZIO *z, void *b, size_t n) {
+  while (n) {
+    size_t m;
+    if (z->n == 0) {  /* no bytes in buffer? */
+      if (luaZ_fill(z) == EOZ)  /* try to read more */
+        return n;  /* no more input; return number of missing bytes */
+      else {
+        z->n++;  /* luaZ_fill consumed first byte; put it back */
+        z->p--;
+      }
+    }
+    m = (n <= z->n) ? n : z->n;  /* min. between n and z->n */
+    memcpy(b, z->p, m);
+    z->n -= m;
+    z->p += m;
+    b = (char *)b + m;
+    n -= m;
+  }
+  return 0;
+}
+
diff --git a/src/lzio.h b/src/lzio.h
new file mode 100644
index 0000000..e7b6f34
--- /dev/null
+++ b/src/lzio.h
@@ -0,0 +1,66 @@
+/*
+** $Id: lzio.h,v 1.31 2015/09/08 15:41:05 roberto Exp $
+** Buffered streams
+** See Copyright Notice in lua.h
+*/
+
+
+#ifndef lzio_h
+#define lzio_h
+
+#include "lua.h"
+
+#include "lmem.h"
+
+
+#define EOZ	(-1)			/* end of stream */
+
+typedef struct Zio ZIO;
+
+#define zgetc(z)  (((z)->n--)>0 ?  cast_uchar(*(z)->p++) : luaZ_fill(z))
+
+
+typedef struct Mbuffer {
+  char *buffer;
+  size_t n;
+  size_t buffsize;
+} Mbuffer;
+
+#define luaZ_initbuffer(L, buff) ((buff)->buffer = NULL, (buff)->buffsize = 0)
+
+#define luaZ_buffer(buff)	((buff)->buffer)
+#define luaZ_sizebuffer(buff)	((buff)->buffsize)
+#define luaZ_bufflen(buff)	((buff)->n)
+
+#define luaZ_buffremove(buff,i)	((buff)->n -= (i))
+#define luaZ_resetbuffer(buff) ((buff)->n = 0)
+
+
+#define luaZ_resizebuffer(L, buff, size) \
+	((buff)->buffer = luaM_reallocvchar(L, (buff)->buffer, \
+				(buff)->buffsize, size), \
+	(buff)->buffsize = size)
+
+#define luaZ_freebuffer(L, buff)	luaZ_resizebuffer(L, buff, 0)
+
+
+LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader,
+                                        void *data);
+LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n);	/* read next n bytes */
+
+
+
+/* --------- Private Part ------------------ */
+
+struct Zio {
+  size_t n;			/* bytes still unread */
+  const char *p;		/* current position in buffer */
+  lua_Reader reader;		/* reader function */
+  void *data;			/* additional data */
+  lua_State *L;			/* Lua state (for reader) */
+};
+
+
+LUAI_FUNC int luaZ_fill (ZIO *z);
+
+#endif