Module:MultiReplace: Difference between revisions

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For a function to search for multiple patterns, see {{#invoke:string2|matchAny}}. For a function to replace multiple parameters at once, see {{#invoke:params|mapping_by_replacing}}.

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

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

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

An equals sign in a pattern will trigger an Unpaired argument error. Use {{=}}, which expands to an equals sign that will not be interpreted.

The above documentation is transcluded from Module:MultiReplace/doc. (edit | history)
Editors can experiment in this module's sandbox (edit | diff) and testcases (create) pages.
Subpages of this module.

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) .. ' = ' .. 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
	if type(frame.args) ~= 'table' then
		args = frame
	elseif frame.args[1] then
		args = frame.args
	else
		args = frame:getParent().args
	end
	return MultiReplace(args)
end

return p