-- This module may be used to compare the arguments passed to the parent -- with a list of arguments, returning a specified result if an argument is -- not on the list local p = {}  local function trim(s)  return s:match('^%s*(.-)%s*$') end  local function isnotempty(s)  return s and s:match('%S') end  local function clean(text)  -- Return text cleaned for display and truncated if too long.  -- Strip markers are replaced with dummy text representing the original wikitext.  local pos, truncated  local function truncate(text)  if truncated then  return ''  end  if mw.ustring.len(text) > 25 then  truncated = true  text = mw.ustring.sub(text, 1, 25) .. '...'  end  return mw.text.nowiki(text)  end  local parts = {}  for before, tag, remainder in text:gmatch('([^\127]*)\127[^\127]*%-(%l+)%-[^\127]*\127()') do  pos = remainder  table.insert(parts, truncate(before) .. '&lt;' .. tag .. '&gt;...&lt;/' .. tag .. '&gt;')  end  table.insert(parts, truncate(text:sub(pos or 1)))  return table.concat(parts) end  function p._check(args, pargs)  if type(args) ~= "table" or type(pargs) ~= "table" then  -- TODO: error handling  return  end   local ignoreblank = isnotempty(args['ignoreblank'])  local showblankpos = isnotempty(args['showblankpositional'])  local knownargs = {}  local unknown = args['unknown'] or 'Found _VALUE_, '  local preview = args['preview']   local values = {}  local res = {}  local regexps = {}   -- create the list of known args, regular expressions, and the return string  for k, v in pairs(args) do  if type(k) == 'number' then  v = trim(v)  knownargs[v] = 1  elseif k:find('^regexp[1-9][0-9]*$') then  table.insert(regexps, '^' .. v .. '$')  end  end  if isnotempty(preview) then  preview = '<div class="hatnote" style="color:red"><strong>หมายเหตุ:</strong> ' .. preview .. ' (ข้อความนี้แสดงเฉพาะเมื่อกำลังแสดงตัวอย่าง)</div>'  elseif preview == nil then  preview = unknown  end   -- loop over the parent args, and make sure they are on the list  for k, v in pairs(pargs) do  if type(k) == 'string' and knownargs[k] == nil then  local knownflag = false  for _, regexp in ipairs(regexps) do  if mw.ustring.match(k, regexp) then  knownflag = true  break  end  end  if not knownflag and ( not ignoreblank or isnotempty(v) ) then  table.insert(values, clean(k))  end  elseif type(k) == 'number' and  knownargs[tostring(k)] == nil and  ( showblankpos or isnotempty(v) )  then  table.insert(values, k .. ' = ' .. clean(v))  end  end   -- add results to the output tables  if #values > 0 then  if mw.getCurrentFrame():preprocess( "{{REVISIONID}}" ) == "" then  unknown = preview  end  for _, v in pairs(values) do  if v == '' then  -- Fix odd bug for | = which gets stripped to the empty string and  -- breaks category links  v = ' '  end  -- avoid error with v = 'example%2' ("invalid capture index")  local r = unknown:gsub('_VALUE_', {_VALUE_ = v})  table.insert(res, r)  end  end   return table.concat(res) end  function p.check(frame)  local args = frame.args  local pargs = frame:getParent().args  return p._check(args, pargs) end  return p