Module:MultiReplace

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Template:For-text Replaces matches of multiple patterns in a given string with given replacements. For each replacement instance, the pattern matching at the lowest position is chosen. If there are multiple such patterns, then the one specified earliest in the pattern list is chosen.

Usage

Template:((#invoke:MultiReplace|main|input|plain=yes (optional)|pattern1| replacement1|pattern2|replacement2... Template:))

If plain=yes is specified, then the patterns and replacements are treated as plain text, otherwise as Lua Unicode patterns.

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local p = {}

local function MultiReplace(args)
	local input = args[1] or "{{{1}}}"
	local plain = args.plain == "yes"

	local i = 1
	local changeList = {}
	while args[i * 2] do
		local change = {pattern = args[i * 2], repl = args[i * 2 + 1]}
		if not change.repl then
			return require('Module:Error').error{
				'MultiReplace: Unpaired argument: <code>' .. (i * 2) .. ' = ' .. mw.text.nowiki(change.pattern) .. '</code>'
			}
		end
		changeList[i] = change
		i = i + 1
	end
	
	local matchList = {}
	local pos = 1
	local len = mw.ustring.len(input)
	local result = ""
	while pos <= len do
		local bestStart = len + 1
		local bestStop = len
		local bestChange
		for _, change in ipairs(changeList) do
			local start, stop = mw.ustring.find(input, change.pattern, pos, plain)
			if start and (start < bestStart) then
				bestStart = start
				bestStop = stop
				bestChange = change
			end
		end
		result = result .. mw.ustring.sub(input, pos, bestStart - 1)
		if bestChange then
			local fragment = mw.ustring.sub(input, bestStart, bestStop)
			result = result .. (plain and bestChange.repl or
				mw.ustring.gsub(fragment, bestChange.pattern, bestChange.repl, 1))
		end
		pos = bestStop + 1
	end
	return result
end

function p.main(frame, ...)
	local args =
		type(frame) ~= 'table' and {frame, ...} or
		type(frame.args) ~= 'table' and frame or
		frame.args[1] and frame.args or
		frame:getParent().args
	return MultiReplace(args)
end

return p