-- This module implements Template:Engvar. -- Template:Engvar is to be build into the template (like an infobox), with default & variant spellings defined. -- That template should also allow parameter '|engvar=' for the editor (article page). -- The module/template Engvar then returns the spelling variant as is set in that article (for example '|engvar=en-GB'). -- The defaultWord is returned, unless the engvar input hits on a defined (en-XX) variant word. local p = {} local getArgs = require('Module:Arguments').getArgs local gsub = string.gsub local lower = string.lower local upper = string.upper  function p.variants(frame) local args = getArgs(frame)  return p._variants(args) end  function p._variants(args) local returnWord = nil   local defaultWord = args.defaultWord or ''  if args.engvar == nil then  -- Nothing to look for; use defaultWord right away  returnWord = defaultWord  elseif args.defaultLang == gsub(lower(args.engvar), '^en%-(%w%w)$', formatISO) then  -- By the defaultLang, the defaultWord is asked  returnWord = defaultWord  else  returnWord = args[gsub(lower(args.engvar), '^en%-(%w%w)$', formatISO)]  end   if returnWord == nil then  -- No hit so far. Search by words in the engvar entered, checking the list  local useLang = engvarLang(args.engvar)  if useLang == nil then  returnWord = defaultWord .. addMaintCat(args)  else  returnWord = args[useLang] or defaultWord  end  end   return returnWord end  -- Returns arguments and intermediate result. Plus the template result, in front. function p.explain(frame) local args = getArgs(frame) local ret = {}  table.insert(ret, '\n\n: Settings:')  table.insert(ret, 'defaultWord=' .. (args.defaultWord or '') .. '; ')  table.insert(ret, 'defaultLang=' .. (args.defaultLang or '') .. '; ')  table.insert(ret, 'engvarCat=' .. (args.engvarCat or '[default:yes]') .. '; ')  table.insert(ret, 'engvarCatSort=' .. (args.engvarCatSort or ''))  table.insert(ret, '\n\n: engvar=' .. (args.engvar or '') .. ' [input] ')  local useLang = engvarLang(args.engvar or '')  table.insert(ret, ' => Engvar code [used]: >' .. (useLang or '') .. '<.')   for k, v in pairs(args) do  if k == 'en-UK' then  table.insert(ret, k .. ' ? better: use "en-GB"; ')  elseif k == 'en-SA' then  table.insert(ret, k .. ' ? misleading; use "en-ZA"; ')  end   if k == 'defaultWord' then  elseif k == 'defaultLang' then  elseif k == 'engvar' then  elseif k == 'engvarcat' then  elseif k == gsub(lower(k), '^en%-(%w%w)$', formatISO) then  table.insert(ret, k .. '=' .. v .. '; ')  else  table.insert(ret, k .. ' [not standard:]=' .. v .. '; ')  end   end  return (args.engvar or '') .. ' => ' .. p._variants(args) .. table.concat(ret, ' ') end  -- Turn a match into pattern 'en-XX' function formatISO(country)  return ('en-' .. upper(country) or '') end  function engvarLang(searchEngvar) -- Search verbose language identifiers to ISO-format 'en-XX' -- Assumed: not a blank string '' to search local match = string.match   searchEngvar = gsub(searchEngvar, '^%s*en%-(.*)', '%1') -- rm any opening 'en-'.  searchEngvar = gsub(lower(searchEngvar), '[%s%(%)%-]', '') -- To lc, remove all: (, ) , ws, hyphen.  local useLang  --Special codes  if match(searchEngvar, 'oxford')  or searchEngvar == 'oed' then  useLang = 'en-OED' -- 'oxford' to catch before anyting 'british'  elseif match(searchEngvar, 'iupac') then  useLang = 'en-IUPAC' -- chemistry  -- Very often used  elseif match(searchEngvar, 'british')  or searchEngvar == 'uk'  or searchEngvar == 'gbr' then  useLang = 'en-GB'  elseif searchEngvar == 'us'  or match(searchEngvar, 'unitedstates')  or searchEngvar == 'american'  or searchEngvar == 'usa' then  useLang = 'en-US'  elseif match(searchEngvar, 'australia')  or searchEngvar == 'aus' then  useLang = 'en-AU'  -- Often used  elseif match(searchEngvar, 'india')  or searchEngvar == 'ind' then  useLang = 'en-IN'  elseif searchEngvar == 'newzealand'  or searchEngvar == 'nzl' then  useLang = 'en-NZ'  elseif match(searchEngvar, 'southafrica') -- not: en-SA  or searchEngvar == 'zaf' then  useLang = 'en-ZA'  elseif searchEngvar == 'canada'  or searchEngvar == 'can' then  useLang = 'en-CA'  elseif match(searchEngvar, 'hiberno')  or match(searchEngvar, 'ireland')  or match(searchEngvar, 'irish')  or searchEngvar == 'irl' then  useLang = 'en-EI'  elseif match(searchEngvar, 'hongkong')  or searchEngvar == 'hkg' then  useLang = 'en-HK'  -- Less often used  elseif match(searchEngvar, 'jamaica')  or searchEngvar == 'jam' then  useLang = 'en-JM'  elseif match(searchEngvar, 'malawi')  or searchEngvar == 'mwi' then  useLang = 'en-MW'  elseif match(searchEngvar, 'nigeria')  or searchEngvar == 'nga' then  useLang = 'en-NG'  elseif match(searchEngvar, 'pakistan')  or searchEngvar == 'pak' then  useLang = 'en-PK'  elseif match(searchEngvar, 'philippine')  or searchEngvar == 'phl' then  useLang = 'en-PH'  elseif match(searchEngvar, 'scotland')  or match(searchEngvar, 'scottish')  or searchEngvar == 'sco' then  useLang = 'en-SCO' -- Has no alpha-2 code; not 'scotch'  elseif match(searchEngvar, 'singapore')  or searchEngvar == 'sgp' then  useLang = 'en-SG'  elseif match(searchEngvar, 'trinidad')  or match(searchEngvar, 'tobago')  or searchEngvar == 'tto' then  useLang = 'en-TT'  else  useLang = nil  end   return useLang end  function addMaintCat(args) local catMaintenance  if args.engvarCat == 'no' then  else  local title = mw.title.getCurrentTitle()  if title:inNamespaces(0) then -- 0=main, 10=templ, 828=module  if args.engvarCatSort then  catMaintenance = '|' .. args.engvarCatSort .. ', ' .. title.text  end  catMaintenance = '[[Category:Articles using an unknown Template:Engvar option' .. (catMaintenance or '') .. ']]'  end  end  return catMaintenance or '' end  return p