refactor(filetype): use extension match instead of pattern if possible

Problem: some patterns are used as a replacement for several explicit
  extension matches (like '%.[Ss][Yy][Ss]$', '%.php%d$', etc.).
  They usually correspond to Vim's "ignore case" regexes (like
  '*.sys\c') and "convenience" patterns to not define many of them (like
  '*.php\d').
  As matching extension directly is faster and more explicit, it should
  be preferred.
Solution: move all such patterns to direct extension match.

runtime/lua/vim/filetype.lua

@@ -273,6 +273,16 @@ local extension = {
   cfm = 'cf',
   cfi = 'cf',
   hgrc = 'cfg',
+  -- Extension match does not conflict with specific patterns such as '.*/etc/a2ps/.*%.cfg', etc.,
+  -- as it is done after those are tried to match
+  cfg = detect.cfg,
+  cfG = detect.cfg,
+  cFg = detect.cfg,
+  cFG = detect.cfg,
+  Cfg = detect.cfg,
+  CfG = detect.cfg,
+  CFg = detect.cfg,
+  CFG = detect.cfg,
   chf = 'ch',
   chai = 'chaiscript',
   ch = detect.change,
@@ -355,6 +365,14 @@ local extension = {
   dart = 'dart',
   drt = 'dart',
   ds = 'datascript',
+  dat = detect.dat,
+  daT = detect.dat,
+  dAt = detect.dat,
+  dAT = detect.dat,
+  Dat = detect.dat,
+  DaT = detect.dat,
+  DAt = detect.dat,
+  DAT = detect.dat,
   dcd = 'dcd',
   decl = detect.decl,
   dec = detect.decl,
@@ -635,6 +653,14 @@ local extension = {
   kts = 'kotlin',
   kt = 'kotlin',
   ktm = 'kotlin',
+  sub = 'krl',
+  suB = 'krl',
+  sUb = 'krl',
+  sUB = 'krl',
+  Sub = 'krl',
+  SuB = 'krl',
+  SUb = 'krl',
+  SUB = 'krl',
   ks = 'kscript',
   k = 'kwt',
   ACE = 'lace',
@@ -668,6 +694,14 @@ local extension = {
   lt = 'lite',
   lite = 'lite',
   livemd = 'livebook',
+  log = detect.log,
+  loG = detect.log,
+  lOg = detect.log,
+  lOG = detect.log,
+  Log = detect.log,
+  LoG = detect.log,
+  LOg = detect.log,
+  LOG = detect.log,
   lgt = 'logtalk',
   lotos = 'lotos',
   lot = detect_line1('\\contentsline', 'tex', 'lotos'),
@@ -734,6 +768,14 @@ local extension = {
   wl = 'mma',
   mmp = 'mmp',
   mms = detect.mms,
+  mod = detect.mod,
+  moD = detect.mod,
+  mOd = detect.mod,
+  mOD = detect.mod,
+  Mod = detect.mod,
+  MoD = detect.mod,
+  MOd = detect.mod,
+  MOD = detect.mod,
   DEF = 'modula2',
   m3 = 'modula3',
   i3 = 'modula3',
@@ -763,6 +805,14 @@ local extension = {
   n1ql = 'n1ql',
   nql = 'n1ql',
   nanorc = 'nanorc',
+  NSA = 'natural',
+  NSC = 'natural',
+  NSG = 'natural',
+  NSL = 'natural',
+  NSM = 'natural',
+  NSN = 'natural',
+  NSP = 'natural',
+  NSS = 'natural',
   ncf = 'ncf',
   nginx = 'nginx',
   nim = 'nim',
@@ -772,6 +822,15 @@ local extension = {
   nix = 'nix',
   norg = 'norg',
   nqc = 'nqc',
+  ['1'] = detect.nroff,
+  ['2'] = detect.nroff,
+  ['3'] = detect.nroff,
+  ['4'] = detect.nroff,
+  ['5'] = detect.nroff,
+  ['6'] = detect.nroff,
+  ['7'] = detect.nroff,
+  ['8'] = detect.nroff,
+  ['9'] = detect.nroff,
   roff = 'nroff',
   tmac = 'nroff',
   man = 'nroff',
@@ -803,6 +862,14 @@ local extension = {
   ['or'] = 'openroad',
   scad = 'openscad',
   ovpn = 'openvpn',
+  opl = 'opl',
+  opL = 'opl',
+  oPl = 'opl',
+  oPL = 'opl',
+  Opl = 'opl',
+  OpL = 'opl',
+  OPl = 'opl',
+  OPL = 'opl',
   ora = 'ora',
   org = 'org',
   org_archive = 'org',
@@ -834,6 +901,16 @@ local extension = {
   ctp = 'php',
   php = 'php',
   phpt = 'php',
+  php0 = 'php',
+  php1 = 'php',
+  php2 = 'php',
+  php3 = 'php',
+  php4 = 'php',
+  php5 = 'php',
+  php6 = 'php',
+  php7 = 'php',
+  php8 = 'php',
+  php9 = 'php',
   phtml = 'php',
   theme = 'php',
   pike = 'pike',
@@ -866,6 +943,14 @@ local extension = {
   it = 'ppwiz',
   ih = 'ppwiz',
   action = 'privoxy',
+  prg = detect.prg,
+  prG = detect.prg,
+  pRg = detect.prg,
+  pRG = detect.prg,
+  Prg = detect.prg,
+  PrG = detect.prg,
+  PRg = detect.prg,
+  PRG = detect.prg,
   pc = 'proc',
   pdb = 'prolog',
   pml = 'promela',
@@ -1043,6 +1128,14 @@ local extension = {
   sqi = 'sqr',
   sqr = 'sqr',
   nut = 'squirrel',
+  src = detect.src,
+  srC = detect.src,
+  sRc = detect.src,
+  sRC = detect.src,
+  Src = detect.src,
+  SrC = detect.src,
+  SRc = detect.src,
+  SRC = detect.src,
   s28 = 'srec',
   s37 = 'srec',
   srec = 'srec',
@@ -1069,6 +1162,14 @@ local extension = {
   swift = 'swift',
   swig = 'swig',
   swg = 'swig',
+  sys = detect.sys,
+  syS = detect.sys,
+  sYs = detect.sys,
+  sYS = detect.sys,
+  Sys = detect.sys,
+  SyS = detect.sys,
+  SYs = detect.sys,
+  SYS = detect.sys,
   svh = 'systemverilog',
   sv = 'systemverilog',
   cmm = 'trace32',
@@ -2210,19 +2311,12 @@ local pattern = {
     ['^bzr_log%.'] = 'bzr',
     ['^cabal%.project%.'] = starsetf('cabalproject'),
     ['^sgml%.catalog'] = starsetf('catalog'),
-    ['%.[Cc][Ff][Gg]$'] = {
-      detect.cfg,
-      -- Decrease priority to avoid conflicts with more specific patterns
-      -- such as '.*/etc/a2ps/.*%.cfg', '.*enlightenment/.*%.cfg', etc.
-      { priority = -1 },
-    },
     ['hgrc$'] = 'cfg',
     ['^[cC]hange[lL]og'] = starsetf(detect.changelog),
     ['%.%.ch$'] = 'chill',
     ['%.cmake%.in$'] = 'cmake',
     ['^crontab%.'] = starsetf('crontab'),
     ['^cvs%d+$'] = 'cvs',
-    ['%.[Dd][Aa][Tt]$'] = detect.dat,
     ['^php%.ini%-'] = 'dosini',
     ['^drac%.'] = starsetf('dracula'),
     ['/dtrace/.*%.d$'] = 'dtrace',
@@ -2253,38 +2347,28 @@ local pattern = {
     ['^[jt]sconfig.*%.json$'] = 'jsonc',
     ['^Config%.in%.'] = starsetf('kconfig'),
     ['^Kconfig%.'] = starsetf('kconfig'),
-    ['%.[Ss][Uu][Bb]$'] = 'krl',
     ['/ldscripts/'] = 'ld',
     ['lftp/rc$'] = 'lftp',
     ['/LiteStep/.*/.*%.rc$'] = 'litestep',
-    ['%.[Ll][Oo][Gg]$'] = detect.log,
     ['^/tmp/SLRN[0-9A-Z.]+$'] = 'mail',
     ['^ae%d+%.txt$'] = 'mail',
     ['^pico%.%d+$'] = 'mail',
     ['^reportbug%-'] = starsetf('mail'),
     ['^snd%.%d+$'] = 'mail',
-    ['%.[Mm][Oo][Dd]$'] = detect.mod,
     ['^rndc.*%.key$'] = 'named',
-    ['%.NS[ACGLMNPS]$'] = 'natural',
-    ['%.[1-9]$'] = detect.nroff,
     ['^tmac%.'] = starsetf('nroff'),
     ['%.ml%.cppo$'] = 'ocaml',
     ['%.mli%.cppo$'] = 'ocaml',
     ['/octave/history$'] = 'octave',
     ['%.opam%.locked$'] = 'opam',
     ['%.opam%.template$'] = 'opam',
-    ['%.[Oo][Pp][Ll]$'] = 'opl',
-    ['%.php%d$'] = 'php',
-    ['%.[Pp][Rr][Gg]$'] = detect.prg,
     ['printcap'] = starsetf(function(path, bufnr)
       return require('vim.filetype.detect').printcap('print')
     end),
     ['/queries/.*%.scm$'] = 'query', -- treesitter queries (Neovim only)
     [',v$'] = 'rcs',
-    ['%.[Ss][Rr][Cc]$'] = detect.src,
     ['^svn%-commit.*%.tmp$'] = 'svn',
     ['%.swift%.gyb$'] = 'swiftgyb',
-    ['%.[Ss][Yy][Ss]$'] = detect.sys,
     ['termcap'] = starsetf(function(path, bufnr)
       return require('vim.filetype.detect').printcap('term')
     end),