Modul:string/sandbox

A modult a Modul:string/sandbox/doc lapon tudod dokumentálni

local export = {}

local UTF8_char = "[%z\1-\127\194-\244][\128-\191]*"

function export.iterChar(str)
	return string.gmatch(str, UTF8_char)
end

function export.fetch(str, index)
	if index <= 0 then
		error("Second argument to fetch must be a positive integer.")
	end
	local i = 0
	for char in iter_char(str) do
		i = i + 1
		if i == index then
			return char
		end
	end
	return ""
end


function export.gsub_with_escapes(frame)
	local params = {
		[1] = { required = true, allow_empty = true },
		[2] = { required = true, allow_empty = true },
		[3] = { required = true, allow_empty = true },
		[4] = { type = "number" },
		extra = { type = "boolean" },
	}
	
	local args = require("Module:parameters").process(frame.args, params)
	
	local letter_escapes = {
		a = "\a", b = "\b", f = "\f", n = "\n", r = "\r", t = "\t", v = "\v",
	}
	
	for i = 1, 3 do
		args[i] = args[i]
			:gsub("\\([abfnrtv])", letter_escapes)
			:gsub("\\(%d%d?%d?)", string.byte)
		
		-- Pretend that Lua 5.1 has Lua 5.3 escapes.
		if args.extra then
			args[i] = args[i]
				:gsub("\\u{(%x+)}", function (hex)
					return mw.ustring.char(tonumber(hex, 16))
				end)
				:gsub("\\x(%x%x)", function (hex)
					return string.char(tonumber(hex, 16))
				end)
		end	
	end
	
	return (mw.ustring.gsub(args[1], args[2], args[3], args[4]))
end

return export