Module:User:Kephir/untranslit

local export = {}

-- "untranslit" is a misnomer, really.
-- given a piece of Cyrillic text and its transliteration with stress marked,
-- this function tries to place the stress mark on the correct Cyrillic letter.
-- very, very ugly... but I think it will do the job.
function export.untranslit(text, tr)
	if type(text) == 'table' then
		text, tr = text.args, text.args
	end
	tr = mw.ustring.toNFD(tr)

	local vo = {}
	for offset in mw.ustring.gmatch(text, '()') do
		table.insert(vo, offset)
	end

	local i, delta = 1, 0
	for accent in mw.ustring.gmatch(tr, '?(?)') do
		if accent ~= "" then
			text = mw.ustring.sub(text, 1, vo + delta) .. accent .. mw.ustring.sub(text, vo + delta + 1)
			delta = delta + 1
		end
		i = i + 1
	end
	text = mw.ustring.gsub(text, "ё", "ё") -- ё should not have an explicit stress marker
	
	return text
end

return export