local p = {}  -- Ripped from Module:Infobox. TODO: Make a utility module that can do this kind of thing local function getArgNums(args, prefix)     -- Returns a table containing the numbers of the arguments that exist     -- for the specified prefix. For example, if the prefix were to be 'data', and     -- 'data1', 'data2', and 'data5' were to exist, it would return {1, 2, 5}.     local nums = {}     for k, v in pairs(args) do         local num = tostring(k):match('^' .. prefix .. '([1-9]%d*)$')         if num then table.insert(nums, tonumber(num)) end     end     table.sort(nums)     return nums end  -- Forked from Module:Unsubst-infobox  local specialParams = { 	['$B'] = 'template content' }  p[] = function ( frame ) 	if not frame.args['$B'] then 		error( ' requires parameter $B (template content)' ) 	end  	if mw.isSubsting() then 		---- substing 		-- Passed args 		local args = {} 		for k, v in pairs( frame:getParent().args ) do 			args[k] = v 		end  		-- Build an equivalent template invocation 		-- First, find the title to use 		local titleobj = mw.title.new(frame:getParent():getTitle()) 		local title 		if titleobj.namespace == 10 then -- NS_TEMPLATE 			title = titleobj.text 		elseif titleobj.namespace == 0 then -- NS_MAIN 			title = ':' .. titleobj.text 		else 			title = titleobj.prefixedText 		end  		-- Remove empty fields 		for k, v in pairs( args ) do 			if v ==  then args[k] = nil end 		end  		-- Pull aliases 		local nums = getArgNums(args, '[Ss]ingle ?') 		for _, num in ipairs(nums) do 			args['single' .. num] = args['single' .. num] or args['single ' .. num] or args['Single ' .. num] 			args['single' .. num .. 'date'] = args['single' .. num .. 'date'] or args['single ' .. num .. ' date'] or args['Single ' .. num .. ' date'] or 			args['single ' .. num], args['Single ' .. num], args['single ' .. num .. ' date'], args['Single ' .. num .. ' date'] = nil, nil, nil, nil 		end 		for k, v in pairs( {Type = 'type', Name = 'name'} ) do 			if args[k] and not args[v] then args[v], args[k] = args[k], nil end 		end  		-- Build the invocation body 		local ret = '{{' .. title  		-- Make parameter list 		local params = {'name', 'type'} 		for _, num in ipairs( nums ) do table.insert( params, 'single' .. num ); table.insert( params, 'single' .. num .. 'date' ) end  		-- Align parameters correctly and remove extra ones 		local maxlength = 0 		for k, v in ipairs( params ) do 			local tmp = mw.ustring.len( v ) 			if tmp > maxlength then maxlength = tmp end 		end  		for k, v in ipairs( params ) do 			ret = ret .. '\n | ' .. v .. string.rep(' ', (maxlength - mw.ustring.len( v ))) .. ' = ' .. (args[v] or ) 		end  		ret = ret .. '\n}}'  		ret = mw.ustring.gsub(ret, '%s+\n', '\n')  		return ret 	else 		-- Not substing 		-- Just return the "body" 		return frame.args['$B'] 	end end  function p.main(frame) 	local args = require('Module:Arguments').getArgs(frame, {wrappers = 'টেমপ্লেট:একক গান'}) 	local out = 	local nums = getArgNums(args, '[Ss]ingle ?') 	for _, num in ipairs(nums) do 		out = out .. '\n# "' .. (args['single' .. num] or args['single ' .. num] or args['Single ' .. num]) .. '"' 		local date = args['single' .. num .. 'date'] or args['single ' .. num .. ' date'] or args['Single ' .. num .. ' date'] 		if date then 			out = out .. 'মুক্তির তারিখ: ' .. date 		end 		out = out .. '' 	end 	 	if out ~=  then 		if mw.ustring.match(out, '</?t[drh][ >]') then out = out .. ' R' end 		return '' .. out .. '\n' 	end 	 	return out end  return p