kc3-lang/SDL/premake/util/sdl_string.lua

Branch : - branch - v2.28 - tag -

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• Author : Sam Lantinga
  Date : 2016-01-02 10:10:34
  Hash : 42065e78
  Message : Updated copyright to 2016

• premake/util/sdl_string.lua

• -- 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