-- This module de-links most wikitext.  require("strict")  local p = {}  local getArgs  local function delinkReversePipeTrick(s) 	if s:match("^%[%[|.*[|\n]") then -- Check for newlines or multiple pipes. 		return s 	end 	return s:match("%[%[|(.*)%]%]")  end  local function delinkPipeTrick(s) 	-- We need to deal with colons, brackets, and commas, per Help:Pipe trick. 	-- First, remove the text before the first colon, if any. 	if s:match(":") then 		s = s:match("%[%[.-:(.*)|%]%]") 	-- If there are no colons, grab all of the text apart from the square brackets and the pipe. 	else 		s = s:match("%[%[(.*)|%]%]") 	end 	 	-- Next up, brackets and commas. 	if s:match("%(.-%)$") then -- Brackets trump commas. 		s = s:match("(.-) ?%(.-%)$") 	elseif s:match(",") then -- If there are no brackets, display only the text before the first comma. 		s = s:match("(.-),.*$") 	end 	return s end  -- Return wikilink target |wikilinks=target local function getDelinkedTarget(s) 	local result = s 	-- Deal with the reverse pipe trick. 	if result:match("%[%[|") then 		return delinkReversePipeTrick(result) 	end 	 	result = mw.uri.decode(result, "PATH") -- decode percent-encoded entities. Leave underscores and plus signs. 	result = mw.text.decode(result, true) -- decode HTML entities. 	 	-- Check for bad titles. To do this we need to find the 	-- title area of the link, i.e. the part before any pipes. 	local target_area 	if result:match("|") then -- Find if we're dealing with a piped link. 		target_area = result:match("^%[%[(.-)|.*%]%]") 	else 		target_area = result:match("^%[%[(.-)%]%]") 	end  	-- Check for bad characters. 	if mw.ustring.match(target_area, "[%[%]<>{}%%%c\n]") and mw.ustring.match(target_area, "[%[%]<>{}%%%c\n]") ~= "?" then 		return s 	end 	 	return target_area end  local function getDelinkedLabel(s) 	local result = s 	-- Deal with the reverse pipe trick. 	if result:match("%[%[|") then 		return delinkReversePipeTrick(result) 	end  	result = mw.uri.decode(result, "PATH") -- decode percent-encoded entities. Leave underscores and plus signs. 	result = mw.text.decode(result, true) -- decode HTML entities.  	-- Check for bad titles. To do this we need to find the 	-- title area of the link, i.e. the part before any pipes. 	local target_area 	if result:match("|") then -- Find if we're dealing with a piped link. 		target_area = result:match("^%[%[(.-)|.*%]%]") 	else 		target_area = result:match("^%[%[(.-)%]%]") 	end  	-- Check for bad characters. 	if mw.ustring.match(target_area, "[%[%]<>{}%%%c\n]") and mw.ustring.match(target_area, "[%[%]<>{}%%%c\n]") ~= "?" then 		return s 	end  	-- Check for categories, interwikis, and files. 	local colon_prefix = result:match("%[%[(.-):.*%]%]") or "" -- Get the text before the first colon. 	local ns = mw.site.namespaces[colon_prefix] -- see if this is a known namespace 	if mw.language.isKnownLanguageTag(colon_prefix) or (ns and (ns.canonicalName == "File" or ns.canonicalName == "Category")) then 		return "" 	end  	-- Remove the colon if the link is using the Help:Colon trick. 	if result:match("%[%[:") then 		result = "[[" .. result:match("%[%[:(.*%]%])") 	end  	-- Deal with links using the Help:Pipe trick. 	if mw.ustring.match(result, "^%[%[[^|]*|%]%]") then 		return delinkPipeTrick(result) 	end 	 	-- Find the display area of the wikilink 	if result:match("|") then -- Find if we're dealing with a piped link. 		result = result:match("^%[%[.-|(.+)%]%]") 		-- Remove new lines from the display of multiline piped links, 		-- where the pipe is before the first new line. 		result = result:gsub("\n", "") 	else 		result = result:match("^%[%[(.-)%]%]") 	end  	return result end  local function delinkURL(s) 	-- Assume we have already delinked internal wikilinks, and that 	-- we have been passed some text between two square brackets [foo]. 	 	-- If the text contains a line break it is not formatted as a URL, regardless of other content. 	if s:match("\n") then 		return s 	end 	 	-- Check if the text has a valid URL prefix and at least one valid URL character. 	local valid_url_prefixes = {"//", "http://", "https://", "ftp://", "gopher://", "mailto:", "news:", "irc://"}  	local url_prefix 	for _ ,v in ipairs(valid_url_prefixes) do 		if mw.ustring.match(s, '^%[' .. v ..'[^"%s].*%]' ) then 			url_prefix = v 			break 		end 	end 	 	-- Get display text 	if not url_prefix then 		return s 	end 	s = s:match("^%[" .. url_prefix .. "(.*)%]") -- Grab all of the text after the URL prefix and before the final square bracket. 	s = s:match('^.-(["<> ].*)') or "" -- Grab all of the text after the first URL separator character ("<> ). 	s = mw.ustring.match(s, "^%s*(%S.*)$") or "" -- If the separating character was a space, trim it off. 	 	local s_decoded = mw.text.decode(s, true) 	if mw.ustring.match(s_decoded, "%c") then 		return s 	end  	return s_decoded  end  local function delinkLinkClass(text, pattern, delinkFunction) 	if type(text) ~= "string" then 		error("Attempt to de-link non-string input.", 2) 	end 	if type(pattern) ~= "string" or mw.ustring.sub(pattern, 1, 1) ~= "^" then 		error('Invalid pattern detected. Patterns must begin with "^".', 2) 	end 	-- Iterate over the text string, and replace any matched text. using the  	-- delink function. We need to iterate character by character rather  	-- than just use gsub, otherwise nested links aren't detected properly. 	local result = "" 	while text ~= "" do 		-- Replace text using one iteration of gsub. 		text = mw.ustring.gsub(text, pattern, delinkFunction, 1) 		-- Append the left-most character to the result string. 		result = result .. mw.ustring.sub(text, 1, 1) 		text = mw.ustring.sub(text, 2, -1) 	end 	return result end  function p._delink(args) 	local text = args[1] or "" 	if args.refs == "yes" then 		-- Remove any Help:Strip markers representing ref tags. In most situations  		-- this is not a good idea - only use it if you know what you are doing! 		text = mw.ustring.gsub(text, "UNIQ%w*%-ref%-%d*%-QINU", "") 	end 	if args.comments ~= "no" then 		text = text:gsub("<!%-%-.-%-%->", "") -- Remove html comments. 	end  	if args.wikilinks ~= "no" and args.wikilinks ~= "target" then 		-- De-link wikilinks and return the label portion of the wikilink. 		text = delinkLinkClass(text, "^%[%[.-%]%]", getDelinkedLabel) 	elseif args.wikilinks == "target" then 		-- De-link wikilinks and return the target portions of the wikilink. 		text = delinkLinkClass(text, "^%[%[.-%]%]", getDelinkedTarget) 	end 	if args.urls ~= "no" then 		text = delinkLinkClass(text, "^%[.-%]", delinkURL) -- De-link URLs. 	end 	if args.whitespace ~= "no" then 		-- Replace single new lines with a single space, but leave double new lines 		-- and new lines only containing spaces or tabs before a second new line. 		text = mw.ustring.gsub(text, "([^\n \t][ \t]*)\n([ \t]*[^\n \t])", "%1 %2") 		text = text:gsub("[ \t]+", " ") -- Remove extra tabs and spaces. 	end 	return text end  function p.delink(frame) 	if not getArgs then 		getArgs = require('Module:Arguments').getArgs 	end 	return p._delink(getArgs(frame, {wrappers = 'টেমপ্লেট:Delink'})) end  return p