" Vim syntax file
" Language:	Scheme (R5RS + some R6RS extras)
" Last Change:	2016 May 23
" Maintainer:	Sergey Khorev <sergey.khorev@gmail.com>
" Original author:	Dirk van Deun <dirk@igwe.vub.ac.be>

" This script incorrectly recognizes some junk input as numerals:
" parsing the complete system of Scheme numerals using the pattern
" language is practically impossible: I did a lax approximation.

" MzScheme extensions can be activated with setting is_mzscheme variable

" Suggestions and bug reports are solicited by the author.

" Initializing:

" For version 5.x: Clear all syntax items
" For version 6.x: Quit when a syntax file was already loaded
if version < 600
  syntax clear
elseif exists("b:current_syntax")
  finish
endif

let s:cpo_save = &cpo
set cpo&vim

syn case ignore

" Fascist highlighting: everything that doesn't fit the rules is an error...

syn match	schemeError	![^ \t()\[\]";]*!
syn match	schemeError	")"

" Quoted and backquoted stuff

syn region schemeQuoted matchgroup=Delimiter start="['`]" end=![ \t()\[\]";]!me=e-1 contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

syn region schemeQuoted matchgroup=Delimiter start="['`](" matchgroup=Delimiter end=")" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc
syn region schemeQuoted matchgroup=Delimiter start="['`]#(" matchgroup=Delimiter end=")" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

syn region schemeStrucRestricted matchgroup=Delimiter start="(" matchgroup=Delimiter end=")" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc
syn region schemeStrucRestricted matchgroup=Delimiter start="#(" matchgroup=Delimiter end=")" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

" Popular Scheme extension:
" using [] as well as ()
syn region schemeStrucRestricted matchgroup=Delimiter start="\[" matchgroup=Delimiter end="\]" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc
syn region schemeStrucRestricted matchgroup=Delimiter start="#\[" matchgroup=Delimiter end="\]" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

syn region schemeUnquote matchgroup=Delimiter start="," end=![ \t\[\]()";]!me=e-1 contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc
syn region schemeUnquote matchgroup=Delimiter start=",@" end=![ \t\[\]()";]!me=e-1 contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

syn region schemeUnquote matchgroup=Delimiter start=",(" end=")" contains=ALL
syn region schemeUnquote matchgroup=Delimiter start=",@(" end=")" contains=ALL

syn region schemeUnquote matchgroup=Delimiter start=",#(" end=")" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc
syn region schemeUnquote matchgroup=Delimiter start=",@#(" end=")" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

syn region schemeUnquote matchgroup=Delimiter start=",\[" end="\]" contains=ALL
syn region schemeUnquote matchgroup=Delimiter start=",@\[" end="\]" contains=ALL

syn region schemeUnquote matchgroup=Delimiter start=",#\[" end="\]" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc
syn region schemeUnquote matchgroup=Delimiter start=",@#\[" end="\]" contains=ALLBUT,schemeStruc,schemeSyntax,schemeFunc

" R5RS Scheme Functions and Syntax:

if version < 600
  set iskeyword=33,35-39,42-58,60-90,94,95,97-122,126,_
else
  setlocal iskeyword=33,35-39,42-58,60-90,94,95,97-122,126,_
endif

syn keyword schemeSyntax lambda and or if cond case define let let* letrec
syn keyword schemeSyntax begin do delay set! else =>
syn keyword schemeSyntax quote quasiquote unquote unquote-splicing
syn keyword schemeSyntax define-syntax let-syntax letrec-syntax syntax-rules
" R6RS
syn keyword schemeSyntax define-record-type fields protocol

syn keyword schemeFunc not boolean? eq? eqv? equal? pair? cons car cdr set-car!
syn keyword schemeFunc set-cdr! caar cadr cdar cddr caaar caadr cadar caddr
syn keyword schemeFunc cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr
syn keyword schemeFunc cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr
syn keyword schemeFunc cddaar cddadr cdddar cddddr null? list? list length
syn keyword schemeFunc append reverse list-ref memq memv member assq assv assoc
syn keyword schemeFunc symbol? symbol->string string->symbol number? complex?
syn keyword schemeFunc real? rational? integer? exact? inexact? = < > <= >=
syn keyword schemeFunc zero? positive? negative? odd? even? max min + * - / abs
syn keyword schemeFunc quotient remainder modulo gcd lcm numerator denominator
syn keyword schemeFunc floor ceiling truncate round rationalize exp log sin cos
syn keyword schemeFunc tan asin acos atan sqrt expt make-rectangular make-polar
syn keyword schemeFunc real-part imag-part magnitude angle exact->inexact
syn keyword schemeFunc inexact->exact number->string string->number char=?
syn keyword schemeFunc char-ci=? char<? char-ci<? char>? char-ci>? char<=?
syn keyword schemeFunc char-ci<=? char>=? char-ci>=? char-alphabetic? char?
syn keyword schemeFunc char-numeric? char-whitespace? char-upper-case?
syn keyword schemeFunc char-lower-case?
syn keyword schemeFunc char->integer integer->char char-upcase char-downcase
syn keyword schemeFunc string? make-string string string-length string-ref
syn keyword schemeFunc string-set! string=? string-ci=? string<? string-ci<?
syn keyword schemeFunc string>? string-ci>? string<=? string-ci<=? string>=?
syn keyword schemeFunc string-ci>=? substring string-append vector? make-vector
syn keyword schemeFunc vector vector-length vector-ref vector-set! procedure?
syn keyword schemeFunc apply map for-each call-with-current-continuation
syn keyword schemeFunc call-with-input-file call-with-output-file input-port?
syn keyword schemeFunc output-port? current-input-port current-output-port
syn keyword schemeFunc open-input-file open-output-file close-input-port
syn keyword schemeFunc close-output-port eof-object? read read-char peek-char
syn keyword schemeFunc write display newline write-char call/cc
syn keyword schemeFunc list-tail string->list list->string string-copy
syn keyword schemeFunc string-fill! vector->list list->vector vector-fill!
syn keyword schemeFunc force with-input-from-file with-output-to-file
syn keyword schemeFunc char-ready? load transcript-on transcript-off eval
syn keyword schemeFunc dynamic-wind port? values call-with-values
syn keyword schemeFunc scheme-report-environment null-environment
syn keyword schemeFunc interaction-environment
" R6RS
syn keyword schemeFunc make-eq-hashtable make-eqv-hashtable make-hashtable
syn keyword schemeFunc hashtable? hashtable-size hashtable-ref hashtable-set!
syn keyword schemeFunc hashtable-delete! hashtable-contains? hashtable-update!
syn keyword schemeFunc hashtable-copy hashtable-clear! hashtable-keys
syn keyword schemeFunc hashtable-entries hashtable-equivalence-function hashtable-hash-function
syn keyword schemeFunc hashtable-mutable? equal-hash string-hash string-ci-hash symbol-hash
syn keyword schemeFunc find for-all exists filter partition fold-left fold-right
syn keyword schemeFunc remp remove remv remq memp assp cons*

" ... so that a single + or -, inside a quoted context, would not be
" interpreted as a number (outside such contexts, it's a schemeFunc)

syn match	schemeDelimiter	!\.[ \t\[\]()";]!me=e-1
syn match	schemeDelimiter	!\.$!
" ... and a single dot is not a number but a delimiter

" This keeps all other stuff unhighlighted, except *stuff* and <stuff>:

syn match	schemeOther	,[a-z!$%&*/:<=>?^_~+@#%-][-a-z!$%&*/:<=>?^_~0-9+.@#%]*,
syn match	schemeError	,[a-z!$%&*/:<=>?^_~+@#%-][-a-z!$%&*/:<=>?^_~0-9+.@#%]*[^-a-z!$%&*/:<=>?^_~0-9+.@ \t\[\]()";]\+[^ \t\[\]()";]*,

syn match	schemeOther	"\.\.\."
syn match	schemeError	!\.\.\.[^ \t\[\]()";]\+!
" ... a special identifier

syn match	schemeConstant	,\*[-a-z!$%&*/:<=>?^_~0-9+.@]\+\*[ \t\[\]()";],me=e-1
syn match	schemeConstant	,\*[-a-z!$%&*/:<=>?^_~0-9+.@]\+\*$,
syn match	schemeError	,\*[-a-z!$%&*/:<=>?^_~0-9+.@]*\*[^-a-z!$%&*/:<=>?^_~0-9+.@ \t\[\]()";]\+[^ \t\[\]()";]*,

syn match	schemeConstant	,<[-a-z!$%&*/:<=>?^_~0-9+.@]*>[ \t\[\]()";],me=e-1
syn match	schemeConstant	,<[-a-z!$%&*/:<=>?^_~0-9+.@]*>$,
syn match	schemeError	,<[-a-z!$%&*/:<=>?^_~0-9+.@]*>[^-a-z!$%&*/:<=>?^_~0-9+.@ \t\[\]()";]\+[^ \t\[\]()";]*,

" Non-quoted lists, and strings:

syn region schemeStruc matchgroup=Delimiter start="(" matchgroup=Delimiter end=")" contains=ALL
syn region schemeStruc matchgroup=Delimiter start="#(" matchgroup=Delimiter end=")" contains=ALL

syn region schemeStruc matchgroup=Delimiter start="\[" matchgroup=Delimiter end="\]" contains=ALL
syn region schemeStruc matchgroup=Delimiter start="#\[" matchgroup=Delimiter end="\]" contains=ALL

" Simple literals:
syn region schemeString start=+\%(\\\)\@<!"+ skip=+\\[\\"]+ end=+"+ contains=@Spell

" Comments:

syn match	schemeComment	";.*$" contains=@Spell


" Writing out the complete description of Scheme numerals without
" using variables is a day's work for a trained secretary...

syn match	schemeOther	![+-][ \t\[\]()";]!me=e-1
syn match	schemeOther	![+-]$!
"
" This is a useful lax approximation:
syn match	schemeNumber	"[-#+.]\=[0-9][-#+/0-9a-f@i.boxesfdl]*"
syn match	schemeError	![-#+0-9.][-#+/0-9a-f@i.boxesfdl]*[^-#+/0-9a-f@i.boxesfdl \t\[\]()";][^ \t\[\]()";]*!

syn match	schemeBoolean	"#[tf]"
syn match	schemeError	!#[tf][^ \t\[\]()";]\+!

syn match	schemeCharacter	"#\\"
syn match	schemeCharacter	"#\\."
syn match       schemeError	!#\\.[^ \t\[\]()";]\+!
syn match	schemeCharacter	"#\\space"
syn match	schemeError	!#\\space[^ \t\[\]()";]\+!
syn match	schemeCharacter	"#\\newline"
syn match	schemeError	!#\\newline[^ \t\[\]()";]\+!

" R6RS
syn match schemeCharacter "#\\x[0-9a-fA-F]\+"


if exists("b:is_mzscheme") || exists("is_mzscheme")
    " MzScheme extensions
    " multiline comment
    syn region	schemeComment start="#|" end="|#" contains=@Spell

    " #%xxx are the special MzScheme identifiers
    syn match schemeOther "#%[-a-z!$%&*/:<=>?^_~0-9+.@#%]\+"
    " anything limited by |'s is identifier
    syn match schemeOther "|[^|]\+|"

    syn match	schemeCharacter	"#\\\%(return\|tab\)"

    " Modules require stmt
    syn keyword schemeExtSyntax module require dynamic-require lib prefix all-except prefix-all-except rename
    " modules provide stmt
    syn keyword schemeExtSyntax provide struct all-from all-from-except all-defined all-defined-except
    " Other from MzScheme
    syn keyword schemeExtSyntax with-handlers when unless instantiate define-struct case-lambda syntax-case
    syn keyword schemeExtSyntax free-identifier=? bound-identifier=? module-identifier=? syntax-object->datum
    syn keyword schemeExtSyntax datum->syntax-object
    syn keyword schemeExtSyntax let-values let*-values letrec-values set!-values fluid-let parameterize begin0
    syn keyword schemeExtSyntax error raise opt-lambda define-values unit unit/sig define-signature
    syn keyword schemeExtSyntax invoke-unit/sig define-values/invoke-unit/sig compound-unit/sig import export
    syn keyword schemeExtSyntax link syntax quasisyntax unsyntax with-syntax

    syn keyword schemeExtFunc format system-type current-extension-compiler current-extension-linker
    syn keyword schemeExtFunc use-standard-linker use-standard-compiler
    syn keyword schemeExtFunc find-executable-path append-object-suffix append-extension-suffix
    syn keyword schemeExtFunc current-library-collection-paths current-extension-compiler-flags make-parameter
    syn keyword schemeExtFunc current-directory build-path normalize-path current-extension-linker-flags
    syn keyword schemeExtFunc file-exists? directory-exists? delete-directory/files delete-directory delete-file
    syn keyword schemeExtFunc system compile-file system-library-subpath getenv putenv current-standard-link-libraries
    syn keyword schemeExtFunc remove* file-size find-files fold-files directory-list shell-execute split-path
    syn keyword schemeExtFunc current-error-port process/ports process printf fprintf open-input-string open-output-string
    syn keyword schemeExtFunc get-output-string
    " exceptions
    syn keyword schemeExtFunc exn exn:application:arity exn:application:continuation exn:application:fprintf:mismatch
    syn keyword schemeExtFunc exn:application:mismatch exn:application:type exn:application:mismatch exn:break exn:i/o:filesystem exn:i/o:port
    syn keyword schemeExtFunc exn:i/o:port:closed exn:i/o:tcp exn:i/o:udp exn:misc exn:misc:application exn:misc:unsupported exn:module exn:read
    syn keyword schemeExtFunc exn:read:non-char exn:special-comment exn:syntax exn:thread exn:user exn:variable exn:application:mismatch
    syn keyword schemeExtFunc exn? exn:application:arity? exn:application:continuation? exn:application:fprintf:mismatch? exn:application:mismatch?
    syn keyword schemeExtFunc exn:application:type? exn:application:mismatch? exn:break? exn:i/o:filesystem? exn:i/o:port? exn:i/o:port:closed?
    syn keyword schemeExtFunc exn:i/o:tcp? exn:i/o:udp? exn:misc? exn:misc:application? exn:misc:unsupported? exn:module? exn:read? exn:read:non-char?
    syn keyword schemeExtFunc exn:special-comment? exn:syntax? exn:thread? exn:user? exn:variable? exn:application:mismatch?
    " Command-line parsing
    syn keyword schemeExtFunc command-line current-command-line-arguments once-any help-labels multi once-each

    " syntax quoting, unquoting and quasiquotation
    syn region schemeUnquote matchgroup=Delimiter start="#," end=![ \t\[\]()";]!me=e-1 contains=ALL
    syn region schemeUnquote matchgroup=Delimiter start="#,@" end=![ \t\[\]()";]!me=e-1 contains=ALL
    syn region schemeUnquote matchgroup=Delimiter start="#,(" end=")" contains=ALL
    syn region schemeUnquote matchgroup=Delimiter start="#,@(" end=")" contains=ALL
    syn region schemeUnquote matchgroup=Delimiter start="#,\[" end="\]" contains=ALL
    syn region schemeUnquote matchgroup=Delimiter start="#,@\[" end="\]" contains=ALL
    syn region schemeQuoted matchgroup=Delimiter start="#['`]" end=![ \t()\[\]";]!me=e-1 contains=ALL
    syn region schemeQuoted matchgroup=Delimiter start="#['`](" matchgroup=Delimiter end=")" contains=ALL

    " Identifiers are very liberal in MzScheme/Racket
    syn match schemeOther ![^()[\]{}",'`;#|\\ ]\+!

    " Language setting
    syn match schemeLang "#lang [-+_/A-Za-z0-9]\+\>"

    " Various number forms
    syn match schemeNumber "[-+]\=[0-9]\+\(\.[0-9]*\)\=\(e[-+]\=[0-9]\+\)\=\>"
    syn match schemeNumber "[-+]\=\.[0-9]\+\(e[-+]\=[0-9]\+\)\=\>"
    syn match schemeNumber "[-+]\=[0-9]\+/[0-9]\+\>"
    syn match schemeNumber "\([-+]\=\([0-9]\+\(\.[0-9]*\)\=\(e[-+]\=[0-9]\+\)\=\|\.[0-9]\+\(e[-+]\=[0-9]\+\)\=\|[0-9]\+/[0-9]\+\)\)\=[-+]\([0-9]\+\(\.[0-9]*\)\=\(e[-+]\=[0-9]\+\)\=\|\.[0-9]\+\(e[-+]\=[0-9]\+\)\=\|[0-9]\+/[0-9]\+\)\=i\>"
endif


if exists("b:is_chicken") || exists("is_chicken")
    " multiline comment
    syntax region schemeMultilineComment start=/#|/ end=/|#/ contains=@Spell,schemeMultilineComment

    syn match schemeOther "##[-a-z!$%&*/:<=>?^_~0-9+.@#%]\+"
    syn match schemeExtSyntax "#:[-a-z!$%&*/:<=>?^_~0-9+.@#%]\+"

    syn keyword schemeExtSyntax unit uses declare hide foreign-declare foreign-parse foreign-parse/spec
    syn keyword schemeExtSyntax foreign-lambda foreign-lambda* define-external define-macro load-library
    syn keyword schemeExtSyntax let-values let*-values letrec-values ->string require-extension
    syn keyword schemeExtSyntax let-optionals let-optionals* define-foreign-variable define-record
    syn keyword schemeExtSyntax pointer tag-pointer tagged-pointer? define-foreign-type
    syn keyword schemeExtSyntax require require-for-syntax cond-expand and-let* receive argc+argv
    syn keyword schemeExtSyntax fixnum? fx= fx> fx< fx>= fx<= fxmin fxmax
    syn keyword schemeExtFunc ##core#inline ##sys#error ##sys#update-errno

    " here-string
    syn region schemeString start=+#<<\s*\z(.*\)+ end=+^\z1$+ contains=@Spell

    if filereadable(expand("<sfile>:p:h")."/cpp.vim")
	unlet! b:current_syntax
	syn include @ChickenC <sfile>:p:h/cpp.vim
	syn region ChickenC matchgroup=schemeOther start=+(\@<=foreign-declare "+ end=+")\@=+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+foreign-declare\s*#<<\z(.*\)$+hs=s+15 end=+^\z1$+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeOther start=+(\@<=foreign-parse "+ end=+")\@=+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+foreign-parse\s*#<<\z(.*\)$+hs=s+13 end=+^\z1$+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeOther start=+(\@<=foreign-parse/spec "+ end=+")\@=+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+foreign-parse/spec\s*#<<\z(.*\)$+hs=s+18 end=+^\z1$+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+#>+ end=+<#+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+#>?+ end=+<#+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+#>!+ end=+<#+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+#>\$+ end=+<#+ contains=@ChickenC
	syn region ChickenC matchgroup=schemeComment start=+#>%+ end=+<#+ contains=@ChickenC
    endif

    " suggested by Alex Queiroz
    syn match schemeExtSyntax "#![-a-z!$%&*/:<=>?^_~0-9+.@#%]\+"
    syn region schemeString start=+#<#\s*\z(.*\)+ end=+^\z1$+ contains=@Spell
endif

" Synchronization and the wrapping up...

syn sync match matchPlace grouphere NONE "^[^ \t]"
" ... i.e. synchronize on a line that starts at the left margin

" Define the default highlighting.
" For version 5.7 and earlier: only when not done already
" For version 5.8 and later: only when an item doesn't have highlighting yet
if version >= 508 || !exists("did_scheme_syntax_inits")
  if version < 508
    let did_scheme_syntax_inits = 1
    command -nargs=+ HiLink hi link <args>
  else
    command -nargs=+ HiLink hi def link <args>
  endif

  HiLink schemeSyntax		Statement
  HiLink schemeFunc		Function

  HiLink schemeString		String
  HiLink schemeCharacter	Character
  HiLink schemeNumber		Number
  HiLink schemeBoolean		Boolean

  HiLink schemeDelimiter	Delimiter
  HiLink schemeConstant		Constant

  HiLink schemeComment		Comment
  HiLink schemeMultilineComment	Comment
  HiLink schemeError		Error

  HiLink schemeExtSyntax	Type
  HiLink schemeExtFunc		PreProc

  HiLink schemeLang		PreProc

  delcommand HiLink
endif

let b:current_syntax = "scheme"

let &cpo = s:cpo_save
unlet s:cpo_save