-- This module implements .  local p = {}  -- This function implements the  template. local function overline(s)     return mw.ustring.format( '%s', s ) end  -- Gets the Roman numerals for a given numeral table. Returns both the string of -- numerals and the value of the number after it is finished being processed. local function getLetters(num, t)     local ret = {}     for _, v in ipairs(t) do         local val, letter = unpack(v)         while num >= val do             num = num - val             table.insert(ret, letter)         end     end      return table.concat(ret), num end  -- The main control flow of the module. local function _main(args)     -- Get input and exit displaying nothing if the input is empty.     if args[1] == nil then return end     local num = tonumber(args[1])     if not num or num < 0 or num == math.huge then     	error('Invalid number ' .. args[1], 2)     elseif num == 0 then         return 'N'     end      -- Return a message for numbers too big to be expressed in Roman numerals.     if num >= 5000000 then         return args[2] or 'N/A'     end      local ret =     -- Find the Roman numerals for the large part of numbers.     -- 23 April 2016 - tweaked to >= 4000 to accept big Roman 'IV'     -- The if statement is not strictly necessary, but makes the algorithm      -- more efficient for smaller numbers.     if num >= 4000 then         local bigRomans = {             { 1000000, 'M' },             { 900000, 'CM' }, { 500000, 'D' }, { 400000, 'CD' }, { 100000, 'C' },             {  90000, 'XC' }, {  50000, 'L' }, {  40000, 'XL' }, {  10000, 'X' },             {   9000, 'IX' }, {   5000, 'V' }, {   4000, 'IV' },         }         local bigLetters         bigLetters, num = getLetters(num, bigRomans)         ret = overline(bigLetters)     end      -- Find the Roman numerals for numbers less than the big Roman threshold.     local smallRomans = {         { 1000, 'M' },         { 900, 'CM' }, { 500, 'D' }, { 400, 'CD' }, { 100, 'C' },         {  90, 'XC' }, {  50, 'L' }, {  40, 'XL' }, {  10, 'X' },         {   9, 'IX' }, {   5, 'V' }, {   4, 'IV' }, {   1, 'I' }     }     local smallLetters = getLetters( num, smallRomans )     ret = ret .. smallLetters      if args.fraction == 'yes' then         -- Find the Roman numerals for the fractional parts of numbers.         -- If num is not a whole number, add half of 1/1728 (the smallest unit) to equate to rounding.         -- Ensure we're not less than the smallest unit or larger than 1 - smallest unit         -- to avoid getting two "half" symbols or no symbols at all         num = num - math.floor(num)         if num ~= 0 then             num = math.max(1.1/1728, math.min(1727.1/1728, num + 1/3456))         end         local fractionalRomans = {             { 1/2, 'S' }, { 5/12, ":•:" }, { 1/3, "::" },             { 1/4, ":•" }, { 1/6, ":" }, { 1/12, '•' },             { 1/24, 'Є' }, { 1/36, 'ƧƧ' }, { 1/48, 'Ɔ' }, { 1/72, 'Ƨ' }, { 1/144, 'Ƨ' },             { 1/288, '℈' }, { 1/1728, '»' },         }         local fractionalLetters = getLetters(num, fractionalRomans)                  ret = ret .. fractionalLetters     end      return ret end  function p.main(frame)     -- If called via #invoke, use the args passed into the invoking     -- template, or the args passed to #invoke if any exist. Otherwise     -- assume args are being passed directly in from the debug console     -- or from another Lua module.     local origArgs     if frame == mw.getCurrentFrame() then         origArgs = frame:getParent().args         for k, v in pairs(frame.args) do             origArgs = frame.args             break         end     else         origArgs = frame     end     -- Trim whitespace and remove blank arguments.     local args = {}     for k, v in pairs(origArgs) do         if type( v ) == 'string' then             v = mw.text.trim(v)         end         if v ~=  then             args[k] = v         end     end          -- exit if not given anything     if args == nil or args == {} then return end     -- Given mathematical expression, simplify to a number     if type(args[1]) == 'string' then         args[1] = mw.ext.ParserFunctions.expr(args[1])     end     return _main(args) end  return p