-- Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org> | |
-- | |
-- This software is provided 'as-is', without any express or implied | |
-- warranty. In no event will the authors be held liable for any damages | |
-- arising from the use of this software. | |
-- | |
-- Permission is granted to anyone to use this software for any purpose, | |
-- including commercial applications, and to alter it and redistribute it | |
-- freely. | |
-- | |
-- Meta-build system using premake created and maintained by | |
-- Benjamin Henning <b.henning@digipen.edu> | |
--[[ | |
sdl_string.lua | |
Contains a few convenient string utility functions which are not supported in | |
Lua or not supported as intended. | |
]] | |
-- Performs a non-pattern based substring search of one string in another | |
-- string. It's of O(n^2) complexity. It returns nil if the result cannot be | |
-- found, otherwise it returns the starting index of the first found occurrence. | |
string.indexOf = function(str, substr) | |
local pos = 1 | |
local i = 1 | |
for i = 1, str:len(), 1 do | |
if str:sub(i, i) == substr:sub(pos, pos) then | |
-- have we matched the complete string? | |
if pos == substr:len() then | |
return i - pos + 1-- starting pos | |
end | |
-- matched character...keep going | |
pos = pos + 1 | |
else | |
-- restart, no match | |
pos = 0 | |
end | |
end | |
if pos == substr:len() then | |
return i - pos + 1 | |
end | |
return nil -- no match | |
end | |
-- This is a public-access version of the explode function defined below. | |
function explode(str, delim) | |
return str:explode(delim) | |
end | |
-- Explodes a string into an array of elements, separated by a non-pattern | |
-- delimiter. This function is part of the string table, allowing for a | |
-- member-based invocation for strings. | |
string.explode = function(str, delim) | |
local exploded = { } | |
local needle = string.find(str, delim) | |
while needle ~= nil do | |
table.insert(exploded, string.sub(str, 0, needle - 1)) | |
str = string.sub(str, needle + 1) | |
needle = string.find(str, delim) | |
end | |
table.insert(exploded, str) | |
return exploded | |
end | |
-- Similar to table.concat, except it supports more advanced token pasting. This | |
-- function is vastly used by the main meta-build script (premake4.lua) to | |
-- generate all the main lines of code for various tables that need to be in the | |
-- generated lua file. | |
-- - tbl: table of values to implode into a string | |
-- - prefix: string to paste before entire result | |
-- - pre: string to always paste before each entry in table | |
-- - post: string to always paste after each entry in table | |
-- - join: string to paste between entries (inclusive) | |
-- - suffix: string to paste after entire result | |
-- Returns the imploded string. | |
function implode(tbl, prefix, pre, post, join, suffix) | |
local result = "" | |
-- not the most efficient way to do this, but... | |
local itbl = { } | |
for k,v in pairs(tbl) do | |
itbl[#itbl + 1] = v | |
end | |
for i = 1, #itbl, 1 do | |
if pre ~= nil then | |
result = result .. pre | |
end | |
result = result .. itbl[i] | |
if post ~= nil then | |
result = result .. post | |
end | |
if i ~= #itbl then | |
result = result .. join | |
end | |
end | |
if prefix ~= nil then | |
result = prefix .. result | |
end | |
if suffix ~= nil then | |
result = result .. suffix | |
end | |
return result | |
end |