Modularize lazy loading of polyglot parts

9 files changed, 480 insertions, 788 deletions

diff --git a/autoload/polyglot.vim b/autoload/polyglot.vim
deleted file mode 100644
index 33210855..00000000
--- a/autoload/polyglot.vim
+++ /dev/null
@@ -1,705 +0,0 @@
-" Please do not edit this file directly, instead modify polyglot.vim or scripts/build
-
-" Line continuation is used here, remove 'C' from 'cpoptions'
-let s:cpo_save = &cpo
-set cpo&vim
-
-func! polyglot#Shebang()
-  if getline(1) =~# "^#!"
-    let ft = polyglot#ShebangFiletype()
-    if ft != ""
-      let &ft = ft
-    endif
-  endif
-
-  if &ft == ""
-    runtime! scripts.vim
-  endif
-
-  return &ft != ""
-endfunc
-
-let s:r_hashbang = '^#!\s*\(\S\+\)\s*\(.*\)\s*'
-let s:r_envflag = '%(\S\+=\S\+\|-[iS]\|--ignore-environment\|--split-string\)'
-let s:r_env = '^\%(\' . s:r_envflag . '\s\+\)*\(\S\+\)'
-
-func! polyglot#ShebangFiletype()
-  let l:line1 = getline(1)
-
-  if l:line1 !~# "^#!"
-    return
-  endif
-
-  let l:pathrest = matchlist(l:line1, s:r_hashbang)
-
-  if len(l:pathrest) == 0
-    return
-  endif
-
-  let [_, l:path, l:rest; __] = l:pathrest
-
-  let l:script = split(l:path, "/")[-1]
-
-  if l:script == "env"
-    let l:argspath = matchlist(l:rest, s:r_env)
-    if len(l:argspath) == 0
-      return
-    endif
-
-    let l:script = l:argspath[1]
-  endif
-
-  if has_key(s:interpreters, l:script)
-    return s:interpreters[l:script]
-  endif
-
-  for interpreter in keys(s:interpreters)
-    if l:script =~# '^' . interpreter
-      return s:interpreters[interpreter]
-    endif
-  endfor
-endfunc
-
-let s:interpreters = {
-  \ 'osascript': 'applescript',
-  \ 'tcc': 'c',
-  \ 'coffee': 'coffee',
-  \ 'crystal': 'crystal',
-  \ 'dart': 'dart',
-  \ 'elixir': 'elixir',
-  \ 'escript': 'erlang',
-  \ 'fish': 'fish',
-  \ 'gnuplot': 'gnuplot',
-  \ 'groovy': 'groovy',
-  \ 'runhaskell': 'haskell',
-  \ 'chakra': 'javascript',
-  \ 'd8': 'javascript',
-  \ 'gjs': 'javascript',
-  \ 'js': 'javascript',
-  \ 'node': 'javascript',
-  \ 'nodejs': 'javascript',
-  \ 'qjs': 'javascript',
-  \ 'rhino': 'javascript',
-  \ 'v8': 'javascript',
-  \ 'v8-shell': 'javascript',
-  \ 'julia': 'julia',
-  \ 'lua': 'lua',
-  \ 'moon': 'moon',
-  \ 'ocaml': 'ocaml',
-  \ 'ocamlrun': 'ocaml',
-  \ 'ocamlscript': 'ocaml',
-  \ 'cperl': 'perl',
-  \ 'perl': 'perl',
-  \ 'php': 'php',
-  \ 'swipl': 'prolog',
-  \ 'yap': 'prolog',
-  \ 'pwsh': 'ps1',
-  \ 'python': 'python',
-  \ 'python2': 'python',
-  \ 'python3': 'python',
-  \ 'qmake': 'qmake',
-  \ 'Rscript': 'r',
-  \ 'racket': 'racket',
-  \ 'perl6': 'raku',
-  \ 'raku': 'raku',
-  \ 'rakudo': 'raku',
-  \ 'ruby': 'ruby',
-  \ 'macruby': 'ruby',
-  \ 'rake': 'ruby',
-  \ 'jruby': 'ruby',
-  \ 'rbx': 'ruby',
-  \ 'scala': 'scala',
-  \ 'ash': 'sh',
-  \ 'bash': 'sh',
-  \ 'dash': 'sh',
-  \ 'ksh': 'sh',
-  \ 'mksh': 'sh',
-  \ 'pdksh': 'sh',
-  \ 'rc': 'sh',
-  \ 'sh': 'sh',
-  \ 'zsh': 'sh',
-  \ 'boolector': 'smt2',
-  \ 'cvc4': 'smt2',
-  \ 'mathsat5': 'smt2',
-  \ 'opensmt': 'smt2',
-  \ 'smtinterpol': 'smt2',
-  \ 'smt-rat': 'smt2',
-  \ 'stp': 'smt2',
-  \ 'verit': 'smt2',
-  \ 'yices2': 'smt2',
-  \ 'z3': 'smt2',
-  \ 'deno': 'typescript',
-  \ 'ts-node': 'typescript',
-\ }
-
-func! polyglot#DetectInpFiletype()
-  let line = getline(nextnonblank(1))
-  if line =~# '^\*'
-    set ft=abaqus | return
-  endif
-  for lnum in range(1, min([line("$"), 500]))
-    let line = getline(lnum)
-    if line =~? '^header surface data'
-      set ft=trasys | return
-    endif
-  endfor
-endfunc
-
-func! polyglot#DetectAsaFiletype()
-  if exists("g:filetype_asa")
-    let &ft = g:filetype_asa | return
-  endif
-  set ft=aspvbs | return
-endfunc
-
-func! polyglot#DetectAspFiletype()
-  if exists("g:filetype_asp")
-    let &ft = g:filetype_asp | return
-  endif
-  for lnum in range(1, min([line("$"), 3]))
-    let line = getline(lnum)
-    if line =~? 'perlscript'
-      set ft=aspperl | return
-    endif
-  endfor
-  set ft=aspvbs | return
-endfunc
-
-func! polyglot#DetectHFiletype()
-  for lnum in range(1, min([line("$"), 200]))
-    let line = getline(lnum)
-    if line =~# '^\s*\(@\(interface\|class\|protocol\|property\|end\|synchronised\|selector\|implementation\)\(\<\|\>\)\|#import\s\+.\+\.h[">]\)'
-      if exists("g:c_syntax_for_h")
-        set ft=objc | return
-      endif
-      set ft=objcpp | return
-    endif
-  endfor
-  if exists("g:c_syntax_for_h")
-    set ft=c | return
-  endif
-  if exists("g:ch_syntax_for_h")
-    set ft=ch | return
-  endif
-  set ft=cpp | return
-endfunc
-
-func! polyglot#DetectMFiletype()
-  let saw_comment = 0
-  for lnum in range(1, min([line("$"), 100]))
-    let line = getline(lnum)
-    if line =~# '^\s*/\*'
-      let saw_comment = 1
-    endif
-    if line =~# '^\s*\(@\(interface\|class\|protocol\|property\|end\|synchronised\|selector\|implementation\)\(\<\|\>\)\|#import\s\+.\+\.h[">]\)'
-      set ft=objc | return
-    endif
-    if line =~# '^\s*%'
-      set ft=octave | return
-    endif
-    if line =~# '^\s*(\*'
-      set ft=mma | return
-    endif
-    if line =~? '^\s*\(\(type\|var\)\(\<\|\>\)\|--\)'
-      set ft=murphi | return
-    endif
-  endfor
-  if saw_comment
-    set ft=objc | return
-  endif
-  if exists("g:filetype_m")
-    let &ft = g:filetype_m | return
-  endif
-  set ft=octave | return
-endfunc
-
-func! polyglot#DetectFsFiletype()
-  for lnum in range(1, min([line("$"), 50]))
-    let line = getline(lnum)
-    if line =~# '^\(: \|new-device\)'
-      set ft=forth | return
-    endif
-    if line =~# '^\s*\(#light\|import\|let\|module\|namespace\|open\|type\)'
-      set ft=fsharp | return
-    endif
-    if line =~# '\s*\(#version\|precision\|uniform\|varying\|vec[234]\)'
-      set ft=glsl | return
-    endif
-  endfor
-  if exists("g:filetype_fs")
-    let &ft = g:filetype_fs | return
-  endif
-  set ft=forth | return
-endfunc
-
-func! polyglot#DetectReFiletype()
-  for lnum in range(1, min([line("$"), 50]))
-    let line = getline(lnum)
-    if line =~# '^\s*#\%(\%(if\|ifdef\|define\|pragma\)\s\+\w\|\s*include\s\+[<"]\|template\s*<\)'
-      set ft=cpp | return
-    endif
-    set ft=reason | return
-  endfor
-endfunc
-
-func! polyglot#DetectIdrFiletype()
-  for lnum in range(1, min([line("$"), 5]))
-    let line = getline(lnum)
-    if line =~# '^\s*--.*[Ii]dris \=1'
-      set ft=idris | return
-    endif
-    if line =~# '^\s*--.*[Ii]dris \=2'
-      set ft=idris2 | return
-    endif
-  endfor
-  for lnum in range(1, min([line("$"), 30]))
-    let line = getline(lnum)
-    if line =~# '^pkgs =.*'
-      set ft=idris | return
-    endif
-    if line =~# '^depends =.*'
-      set ft=idris2 | return
-    endif
-    if line =~# '^%language \(TypeProviders\|ElabReflection\)'
-      set ft=idris | return
-    endif
-    if line =~# '^%language PostfixProjections'
-      set ft=idris2 | return
-    endif
-    if line =~# '^%access .*'
-      set ft=idris | return
-    endif
-  endfor
-  if exists("g:filetype_idr")
-    let &ft = g:filetype_idr | return
-  endif
-  set ft=idris2 | return
-endfunc
-
-func! polyglot#DetectLidrFiletype()
-  for lnum in range(1, min([line("$"), 200]))
-    let line = getline(lnum)
-    if line =~# '^>\s*--.*[Ii]dris \=1'
-      set ft=lidris | return
-    endif
-  endfor
-  set ft=lidris2 | return
-endfunc
-
-func! polyglot#DetectBasFiletype()
-  for lnum in range(1, min([line("$"), 5]))
-    let line = getline(lnum)
-    if line =~? 'VB_Name\|Begin VB\.\(Form\|MDIForm\|UserControl\)'
-      set ft=vb | return
-    endif
-  endfor
-  set ft=basic | return
-endfunc
-
-func! polyglot#DetectPmFiletype()
-  let line = getline(nextnonblank(1))
-  if line =~# 'XPM2'
-    set ft=xpm2 | return
-  endif
-  if line =~# 'XPM'
-    set ft=xpm | return
-  endif
-  for lnum in range(1, min([line("$"), 50]))
-    let line = getline(lnum)
-    if line =~# '^\s*\%(use\s\+v6\(\<\|\>\)\|\(\<\|\>\)module\(\<\|\>\)\|\(\<\|\>\)\%(my\s\+\)\=class\(\<\|\>\)\)'
-      set ft=raku | return
-    endif
-    if line =~# '\(\<\|\>\)use\s\+\%(strict\(\<\|\>\)\|v\=5\.\)'
-      set ft=perl | return
-    endif
-  endfor
-  if exists("g:filetype_pm")
-    let &ft = g:filetype_pm | return
-  endif
-  set ft=perl | return
-endfunc
-
-func! polyglot#DetectPlFiletype()
-  let line = getline(nextnonblank(1))
-  if line =~# '^[^#]*:-' || line =~# '^\s*\%(%\|/\*\)' || line =~# '\.\s*$'
-    set ft=prolog | return
-  endif
-  for lnum in range(1, min([line("$"), 50]))
-    let line = getline(lnum)
-    if line =~# '^\s*\%(use\s\+v6\(\<\|\>\)\|\(\<\|\>\)module\(\<\|\>\)\|\(\<\|\>\)\%(my\s\+\)\=class\(\<\|\>\)\)'
-      set ft=raku | return
-    endif
-    if line =~# '\(\<\|\>\)use\s\+\%(strict\(\<\|\>\)\|v\=5\.\)'
-      set ft=perl | return
-    endif
-  endfor
-  if exists("g:filetype_pl")
-    let &ft = g:filetype_pl | return
-  endif
-  set ft=perl | return
-endfunc
-
-func! polyglot#DetectTFiletype()
-  for lnum in range(1, min([line("$"), 5]))
-    let line = getline(lnum)
-    if line =~# '^\.'
-      set ft=nroff | return
-    endif
-  endfor
-  for lnum in range(1, min([line("$"), 50]))
-    let line = getline(lnum)
-    if line =~# '^\s*\%(use\s\+v6\(\<\|\>\)\|\(\<\|\>\)module\(\<\|\>\)\|\(\<\|\>\)\%(my\s\+\)\=class\(\<\|\>\)\)'
-      set ft=raku | return
-    endif
-    if line =~# '\(\<\|\>\)use\s\+\%(strict\(\<\|\>\)\|v\=5\.\)'
-      set ft=perl | return
-    endif
-  endfor
-  if exists("g:filetype_t")
-    let &ft = g:filetype_t | return
-  endif
-  set ft=perl | return
-endfunc
-
-func! polyglot#DetectTt2Filetype()
-  for lnum in range(1, min([line("$"), 3]))
-    let line = getline(lnum)
-    if line =~? '<\%(!DOCTYPE HTML\|[%?]\|html\)'
-      set ft=tt2html | return
-    endif
-  endfor
-  set ft=tt2 | return
-endfunc
-
-func! polyglot#DetectHtmlFiletype()
-  let line = getline(nextnonblank(1))
-  if line =~# '^\(%\|<[%&].*>\)'
-    set ft=mason | return
-  endif
-  for lnum in range(1, min([line("$"), 50]))
-    let line = getline(lnum)
-    if line =~# '{%-\=\s*\(end.*\|extends\|block\|macro\|set\|if\|for\|include\|trans\)\(\<\|\>\)\|{#\s\+'
-      set ft=htmldjango | return
-    endif
-    if line =~# '\(\<\|\>\)DTD\s\+XHTML\s'
-      set ft=xhtml | return
-    endif
-  endfor
-  set ft=html | au! BufWritePost <buffer> ++once call polyglot#DetectHtmlFiletype()
-  return
-endfunc
-
-
-" Restore 'cpoptions'
-let &cpo = s:cpo_save
-unlet s:cpo_save
-
-""" ftdetect/polyglot.vim
-
-" don't spam the user when Vim is started in Vi compatibility mode
-let s:cpo_save = &cpo
-set cpo&vim
-
-" Disable all native vim ftdetect
-if exists('g:polyglot_test')
-  autocmd!
-endif
-
-func! s:Observe(fn)
-  let b:polyglot_observe = a:fn
-  augroup polyglot-observer
-    au! CursorHold,CursorHoldI,BufWritePost <buffer>
-      \ execute('if polyglot#' . b:polyglot_observe . '() | au! polyglot-observer | endif')
-  augroup END
-endfunc
-
-let s:disabled_packages = {}
-let s:new_polyglot_disabled = []
-
-if exists('g:polyglot_disabled')
-  for pkg in g:polyglot_disabled
-    let base = split(pkg, '\.')
-    if len(base) > 0
-      let s:disabled_packages[pkg] = 1
-      call add(s:new_polyglot_disabled, base[0]) 
-    endif
-  endfor
-else
-  let g:polyglot_disabled_not_set = 1
-endif
-
-function! s:SetDefault(name, value)
-  if !exists(a:name)
-    let {a:name} = a:value
-  endif
-endfunction
-
-call s:SetDefault('g:markdown_enable_spell_checking', 0)
-call s:SetDefault('g:markdown_enable_input_abbreviations', 0)
-call s:SetDefault('g:markdown_enable_mappings', 0)
-
-" Enable jsx syntax by default
-call s:SetDefault('g:jsx_ext_required', 0)
-
-" Needed for sql highlighting
-call s:SetDefault('g:javascript_sql_dialect', 'sql')
-
-" Make csv loading faster
-call s:SetDefault('g:csv_start', 1)
-call s:SetDefault('g:csv_end', 2)
-
-" Disable json concealing by default
-call s:SetDefault('g:vim_json_syntax_conceal', 0)
-
-call s:SetDefault('g:filetype_euphoria', 'elixir')
-
-if !exists('g:python_highlight_all')
-  call s:SetDefault('g:python_highlight_builtins', 1)
-  call s:SetDefault('g:python_highlight_builtin_objs', 1)
-  call s:SetDefault('g:python_highlight_builtin_types', 1)
-  call s:SetDefault('g:python_highlight_builtin_funcs', 1)
-  call s:SetDefault('g:python_highlight_builtin_funcs_kwarg', 1)
-  call s:SetDefault('g:python_highlight_exceptions', 1)
-  call s:SetDefault('g:python_highlight_string_formatting', 1)
-  call s:SetDefault('g:python_highlight_string_format', 1)
-  call s:SetDefault('g:python_highlight_string_templates', 1)
-  call s:SetDefault('g:python_highlight_indent_errors', 1)
-  call s:SetDefault('g:python_highlight_space_errors', 1)
-  call s:SetDefault('g:python_highlight_doctests', 1)
-  call s:SetDefault('g:python_highlight_func_calls', 1)
-  call s:SetDefault('g:python_highlight_class_vars', 1)
-  call s:SetDefault('g:python_highlight_operators', 1)
-  call s:SetDefault('g:python_highlight_file_headers_as_comments', 1)
-  call s:SetDefault('g:python_slow_sync', 1)
-endif
-
-" We need it because scripts.vim in vim uses "set ft=" which cannot be
-" overridden with setf (and we can't use set ft= so our scripts.vim work)
-func! s:Setf(ft)
-  if &filetype !~# '\<'.a:ft.'\>'
-    let &filetype = a:ft
-  endif
-endfunc
-
-" Function used for patterns that end in a star: don't set the filetype if the
-" file name matches ft_ignore_pat.
-" When using this, the entry should probably be further down below with the
-" other StarSetf() calls.
-func! s:StarSetf(ft)
-  if expand("<amatch>") !~ g:ft_ignore_pat && &filetype !~# '\<'.a:ft.'\>'
-    let &filetype = a:ft
-  endif
-endfunc
-
-augroup filetypedetect
-
-" scripts/build inserts here filetype detection autocommands
-
-au! BufNewFile,BufRead,StdinReadPost * if expand("<afile>") !~ g:ft_ignore_pat |
-  \ call polyglot#Shebang() | endif
-
-au BufEnter * if &ft == "" && expand("<afile>") !~ g:ft_ignore_pat |
-      \ call s:Observe('Shebang') | endif
-
-augroup END
-
-if !has_key(s:disabled_packages, 'autoindent')
-  " Code below re-implements sleuth for vim-polyglot
-  let g:loaded_sleuth = 1
-  let g:loaded_foobar = 1
-
-  " Makes shiftwidth to be synchronized with tabstop by default
-  if &shiftwidth == &tabstop
-    let &shiftwidth = 0
-  endif
-
-  function! s:guess(lines) abort
-    let options = {}
-    let ccomment = 0
-    let podcomment = 0
-    let triplequote = 0
-    let backtick = 0
-    let xmlcomment = 0
-    let heredoc = ''
-    let minindent = 10
-    let spaces_minus_tabs = 0
-    let i = 0
-
-    for line in a:lines
-      let i += 1
-
-      if !len(line) || line =~# '^\W*$'
-        continue
-      endif
-
-      if line =~# '^\s*/\*'
-        let ccomment = 1
-      endif
-      if ccomment
-        if line =~# '\*/'
-          let ccomment = 0
-        endif
-        continue
-      endif
-
-      if line =~# '^=\w'
-        let podcomment = 1
-      endif
-      if podcomment
-        if line =~# '^=\%(end\|cut\)\>'
-          let podcomment = 0
-        endif
-        continue
-      endif
-
-      if triplequote
-        if line =~# '^[^"]*"""[^"]*$'
-          let triplequote = 0
-        endif
-        continue
-      elseif line =~# '^[^"]*"""[^"]*$'
-        let triplequote = 1
-      endif
-
-      if backtick
-        if line =~# '^[^`]*`[^`]*$'
-          let backtick = 0
-        endif
-        continue
-      elseif &filetype ==# 'go' && line =~# '^[^`]*`[^`]*$'
-        let backtick = 1
-      endif
-
-      if line =~# '^\s*<\!--'
-        let xmlcomment = 1
-      endif
-      if xmlcomment
-        if line =~# '-->'
-          let xmlcomment = 0
-        endif
-        continue
-      endif
-
-      " This is correct order because both "<<EOF" and "EOF" matches end
-      if heredoc != ''
-        if line =~# heredoc
-          let heredoc = ''
-        endif
-        continue
-      endif
-      let herematch = matchlist(line, '\C<<\W*\([A-Z]\+\)\s*$')
-      if len(herematch) > 0
-        let heredoc = herematch[1] . '$'
-      endif
-
-      let spaces_minus_tabs += line[0] == "\t" ? 1 : -1
-
-      if line[0] == "\t"
-        setlocal noexpandtab
-        let &l:shiftwidth=&tabstop
-        let b:sleuth_culprit .= ':' . i
-        return 1
-      elseif line[0] == " "
-        let indent = len(matchstr(line, '^ *'))
-        if (indent % 2 == 0 || indent % 3 == 0) && indent < minindent
-          let minindent = indent
-        endif
-      endif
-    endfor
-
-    if minindent < 10
-      setlocal expandtab
-      let &l:shiftwidth=minindent
-      let b:sleuth_culprit .= ':' . i
-      return 1
-    endif
-
-    return 0
-  endfunction
-
-  function! s:detect_indent() abort
-    if &buftype ==# 'help'
-      return
-    endif
-
-    let b:sleuth_culprit = expand("<afile>:p")
-    if s:guess(getline(1, 32))
-      return
-    endif
-    let pattern = sleuth#GlobForFiletype(&filetype)
-    if len(pattern) == 0
-      return
-    endif
-    let pattern = '{' . pattern . ',.git,.svn,.hg}'
-    let dir = expand('%:p:h')
-    let level = 3
-    while isdirectory(dir) && dir !=# fnamemodify(dir, ':h') && level > 0
-      " Ignore files from homedir and root 
-      if dir == expand('~') || dir == '/'
-        unlet b:sleuth_culprit
-        return
-      endif
-      for neighbor in glob(dir . '/' . pattern, 0, 1)[0:level]
-        let b:sleuth_culprit = neighbor
-        " Do not consider directories above .git, .svn or .hg
-        if fnamemodify(neighbor, ":h:t")[0] == "."
-          let level = 0
-          continue
-        endif
-        if neighbor !=# expand('%:p') && filereadable(neighbor)
-          if s:guess(readfile(neighbor, '', 32))
-            return
-          endif
-        endif
-      endfor
-
-      let dir = fnamemodify(dir, ':h')
-      let level -= 1
-    endwhile
-
-    unlet b:sleuth_culprit
-  endfunction
-
-  setglobal smarttab
-
-  function! SleuthIndicator() abort
-    let sw = &shiftwidth ? &shiftwidth : &tabstop
-    if &expandtab
-      return 'sw='.sw
-    elseif &tabstop == sw
-      return 'ts='.&tabstop
-    else
-      return 'sw='.sw.',ts='.&tabstop
-    endif
-  endfunction
-
-  augroup polyglot-sleuth
-    au!
-    au FileType * call s:detect_indent()
-    au User Flags call Hoist('buffer', 5, 'SleuthIndicator')
-  augroup END
-
-  command! -bar -bang Sleuth call s:detect_indent()
-endif
-
-func! s:verify()
-  if exists("g:polyglot_disabled_not_set")
-    if exists("g:polyglot_disabled")
-      echohl WarningMsg
-      echo "vim-polyglot: g:polyglot_disabled should be defined before loading vim-polyglot"
-      echohl None
-    endif
-
-    unlet g:polyglot_disabled_not_set
-  endif
-endfunc
-
-au VimEnter * call s:verify()
-
-" Save polyglot_disabled without postfixes
-if exists('g:polyglot_disabled')
-  let g:polyglot_disabled = s:new_polyglot_disabled
-endif
-
-" restore Vi compatibility settings
-let &cpo = s:cpo_save
\ No newline at end of file
diff --git a/autoload/polyglot/detect.vim b/autoload/polyglot/detect.vim
new file mode 100644
index 00000000..e92d4d12
--- /dev/null
+++ b/autoload/polyglot/detect.vim
@@ -0,0 +1,262 @@
+func! polyglot#detect#Inp()
+  let line = getline(nextnonblank(1))
+  if line =~# '^\*'
+    set ft=abaqus | return
+  endif
+  for lnum in range(1, min([line("$"), 500]))
+    let line = getline(lnum)
+    if line =~? '^header surface data'
+      set ft=trasys | return
+    endif
+  endfor
+endfunc
+
+func! polyglot#detect#Asa()
+  if exists("g:filetype_asa")
+    let &ft = g:filetype_asa | return
+  endif
+  set ft=aspvbs | return
+endfunc
+
+func! polyglot#detect#Asp()
+  if exists("g:filetype_asp")
+    let &ft = g:filetype_asp | return
+  endif
+  for lnum in range(1, min([line("$"), 3]))
+    let line = getline(lnum)
+    if line =~? 'perlscript'
+      set ft=aspperl | return
+    endif
+  endfor
+  set ft=aspvbs | return
+endfunc
+
+func! polyglot#detect#H()
+  for lnum in range(1, min([line("$"), 200]))
+    let line = getline(lnum)
+    if line =~# '^\s*\(@\(interface\|class\|protocol\|property\|end\|synchronised\|selector\|implementation\)\(\<\|\>\)\|#import\s\+.\+\.h[">]\)'
+      if exists("g:c_syntax_for_h")
+        set ft=objc | return
+      endif
+      set ft=objcpp | return
+    endif
+  endfor
+  if exists("g:c_syntax_for_h")
+    set ft=c | return
+  endif
+  if exists("g:ch_syntax_for_h")
+    set ft=ch | return
+  endif
+  set ft=cpp | return
+endfunc
+
+func! polyglot#detect#M()
+  let saw_comment = 0
+  for lnum in range(1, min([line("$"), 100]))
+    let line = getline(lnum)
+    if line =~# '^\s*/\*'
+      let saw_comment = 1
+    endif
+    if line =~# '^\s*\(@\(interface\|class\|protocol\|property\|end\|synchronised\|selector\|implementation\)\(\<\|\>\)\|#import\s\+.\+\.h[">]\)'
+      set ft=objc | return
+    endif
+    if line =~# '^\s*%'
+      set ft=octave | return
+    endif
+    if line =~# '^\s*(\*'
+      set ft=mma | return
+    endif
+    if line =~? '^\s*\(\(type\|var\)\(\<\|\>\)\|--\)'
+      set ft=murphi | return
+    endif
+  endfor
+  if saw_comment
+    set ft=objc | return
+  endif
+  if exists("g:filetype_m")
+    let &ft = g:filetype_m | return
+  endif
+  set ft=octave | return
+endfunc
+
+func! polyglot#detect#Fs()
+  for lnum in range(1, min([line("$"), 50]))
+    let line = getline(lnum)
+    if line =~# '^\(: \|new-device\)'
+      set ft=forth | return
+    endif
+    if line =~# '^\s*\(#light\|import\|let\|module\|namespace\|open\|type\)'
+      set ft=fsharp | return
+    endif
+    if line =~# '\s*\(#version\|precision\|uniform\|varying\|vec[234]\)'
+      set ft=glsl | return
+    endif
+  endfor
+  if exists("g:filetype_fs")
+    let &ft = g:filetype_fs | return
+  endif
+  set ft=forth | return
+endfunc
+
+func! polyglot#detect#Re()
+  for lnum in range(1, min([line("$"), 50]))
+    let line = getline(lnum)
+    if line =~# '^\s*#\%(\%(if\|ifdef\|define\|pragma\)\s\+\w\|\s*include\s\+[<"]\|template\s*<\)'
+      set ft=cpp | return
+    endif
+    set ft=reason | return
+  endfor
+endfunc
+
+func! polyglot#detect#Idr()
+  for lnum in range(1, min([line("$"), 5]))
+    let line = getline(lnum)
+    if line =~# '^\s*--.*[Ii]dris \=1'
+      set ft=idris | return
+    endif
+    if line =~# '^\s*--.*[Ii]dris \=2'
+      set ft=idris2 | return
+    endif
+  endfor
+  for lnum in range(1, min([line("$"), 30]))
+    let line = getline(lnum)
+    if line =~# '^pkgs =.*'
+      set ft=idris | return
+    endif
+    if line =~# '^depends =.*'
+      set ft=idris2 | return
+    endif
+    if line =~# '^%language \(TypeProviders\|ElabReflection\)'
+      set ft=idris | return
+    endif
+    if line =~# '^%language PostfixProjections'
+      set ft=idris2 | return
+    endif
+    if line =~# '^%access .*'
+      set ft=idris | return
+    endif
+  endfor
+  if exists("g:filetype_idr")
+    let &ft = g:filetype_idr | return
+  endif
+  set ft=idris2 | return
+endfunc
+
+func! polyglot#detect#Lidr()
+  for lnum in range(1, min([line("$"), 200]))
+    let line = getline(lnum)
+    if line =~# '^>\s*--.*[Ii]dris \=1'
+      set ft=lidris | return
+    endif
+  endfor
+  set ft=lidris2 | return
+endfunc
+
+func! polyglot#detect#Bas()
+  for lnum in range(1, min([line("$"), 5]))
+    let line = getline(lnum)
+    if line =~? 'VB_Name\|Begin VB\.\(Form\|MDIForm\|UserControl\)'
+      set ft=vb | return
+    endif
+  endfor
+  set ft=basic | return
+endfunc
+
+func! polyglot#detect#Pm()
+  let line = getline(nextnonblank(1))
+  if line =~# 'XPM2'
+    set ft=xpm2 | return
+  endif
+  if line =~# 'XPM'
+    set ft=xpm | return
+  endif
+  for lnum in range(1, min([line("$"), 50]))
+    let line = getline(lnum)
+    if line =~# '^\s*\%(use\s\+v6\(\<\|\>\)\|\(\<\|\>\)module\(\<\|\>\)\|\(\<\|\>\)\%(my\s\+\)\=class\(\<\|\>\)\)'
+      set ft=raku | return
+    endif
+    if line =~# '\(\<\|\>\)use\s\+\%(strict\(\<\|\>\)\|v\=5\.\)'
+      set ft=perl | return
+    endif
+  endfor
+  if exists("g:filetype_pm")
+    let &ft = g:filetype_pm | return
+  endif
+  if polyglot#shebang#Detect() | return | endif
+  set ft=perl | au! BufWritePost <buffer> ++once call polyglot#detect#Pm()
+  return
+endfunc
+
+func! polyglot#detect#Pl()
+  let line = getline(nextnonblank(1))
+  if line =~# '^[^#]*:-' || line =~# '^\s*\%(%\|/\*\)' || line =~# '\.\s*$'
+    set ft=prolog | return
+  endif
+  for lnum in range(1, min([line("$"), 50]))
+    let line = getline(lnum)
+    if line =~# '^\s*\%(use\s\+v6\(\<\|\>\)\|\(\<\|\>\)module\(\<\|\>\)\|\(\<\|\>\)\%(my\s\+\)\=class\(\<\|\>\)\)'
+      set ft=raku | return
+    endif
+    if line =~# '\(\<\|\>\)use\s\+\%(strict\(\<\|\>\)\|v\=5\.\)'
+      set ft=perl | return
+    endif
+  endfor
+  if exists("g:filetype_pl")
+    let &ft = g:filetype_pl | return
+  endif
+  if polyglot#shebang#Detect() | return | endif
+  set ft=perl | au! BufWritePost <buffer> ++once call polyglot#detect#Pl()
+  return
+endfunc
+
+func! polyglot#detect#T()
+  for lnum in range(1, min([line("$"), 5]))
+    let line = getline(lnum)
+    if line =~# '^\.'
+      set ft=nroff | return
+    endif
+  endfor
+  for lnum in range(1, min([line("$"), 50]))
+    let line = getline(lnum)
+    if line =~# '^\s*\%(use\s\+v6\(\<\|\>\)\|\(\<\|\>\)module\(\<\|\>\)\|\(\<\|\>\)\%(my\s\+\)\=class\(\<\|\>\)\)'
+      set ft=raku | return
+    endif
+    if line =~# '\(\<\|\>\)use\s\+\%(strict\(\<\|\>\)\|v\=5\.\)'
+      set ft=perl | return
+    endif
+  endfor
+  if exists("g:filetype_t")
+    let &ft = g:filetype_t | return
+  endif
+  if polyglot#shebang#Detect() | return | endif
+  set ft=perl | au! BufWritePost <buffer> ++once call polyglot#detect#T()
+  return
+endfunc
+
+func! polyglot#detect#Tt2()
+  for lnum in range(1, min([line("$"), 3]))
+    let line = getline(lnum)
+    if line =~? '<\%(!DOCTYPE HTML\|[%?]\|html\)'
+      set ft=tt2html | return
+    endif
+  endfor
+  set ft=tt2 | return
+endfunc
+
+func! polyglot#detect#Html()
+  let line = getline(nextnonblank(1))
+  if line =~# '^\(%\|<[%&].*>\)'
+    set ft=mason | return
+  endif
+  for lnum in range(1, min([line("$"), 50]))
+    let line = getline(lnum)
+    if line =~# '{%-\=\s*\(end.*\|extends\|block\|macro\|set\|if\|for\|include\|trans\)\(\<\|\>\)\|{#\s\+'
+      set ft=htmldjango | return
+    endif
+    if line =~# '\(\<\|\>\)DTD\s\+XHTML\s'
+      set ft=xhtml | return
+    endif
+  endfor
+  set ft=html | au! BufWritePost <buffer> ++once call polyglot#detect#Html()
+  return
+endfunc
diff --git a/autoload/polyglot/shebang.vim b/autoload/polyglot/shebang.vim
new file mode 100644
index 00000000..bf2a793a
--- /dev/null
+++ b/autoload/polyglot/shebang.vim
@@ -0,0 +1,129 @@
+" Please do not edit this file directly, instead modify polyglot.vim or scripts/build
+
+func! polyglot#shebang#Detect()
+  let ft = s:Filetype()
+  if ft != ""
+    let &ft = ft
+  endif
+
+  if &ft == ""
+    runtime! scripts.vim
+  endif
+
+  return &ft != ""
+endfunc
+
+let s:r_hashbang = '^#!\s*\(\S\+\)\s*\(.*\)\s*'
+let s:r_envflag = '%(\S\+=\S\+\|-[iS]\|--ignore-environment\|--split-string\)'
+let s:r_env = '^\%(\' . s:r_envflag . '\s\+\)*\(\S\+\)'
+
+func! s:Filetype()
+  let l:line1 = getline(1)
+
+  if l:line1 !~# "^#!"
+    return
+  endif
+
+  let l:pathrest = matchlist(l:line1, s:r_hashbang)
+
+  if len(l:pathrest) == 0
+    return
+  endif
+
+  let [_, l:path, l:rest; __] = l:pathrest
+
+  let l:script = split(l:path, "/")[-1]
+
+  if l:script == "env"
+    let l:argspath = matchlist(l:rest, s:r_env)
+    if len(l:argspath) == 0
+      return
+    endif
+
+    let l:script = l:argspath[1]
+  endif
+
+  if has_key(s:interpreters, l:script)
+    return s:interpreters[l:script]
+  endif
+
+  for interpreter in keys(s:interpreters)
+    if l:script =~# '^' . interpreter
+      return s:interpreters[interpreter]
+    endif
+  endfor
+endfunc
+
+
+
+let s:interpreters = {
+  \ 'osascript': 'applescript',
+  \ 'tcc': 'c',
+  \ 'coffee': 'coffee',
+  \ 'crystal': 'crystal',
+  \ 'dart': 'dart',
+  \ 'elixir': 'elixir',
+  \ 'escript': 'erlang',
+  \ 'fish': 'fish',
+  \ 'gnuplot': 'gnuplot',
+  \ 'groovy': 'groovy',
+  \ 'runhaskell': 'haskell',
+  \ 'chakra': 'javascript',
+  \ 'd8': 'javascript',
+  \ 'gjs': 'javascript',
+  \ 'js': 'javascript',
+  \ 'node': 'javascript',
+  \ 'nodejs': 'javascript',
+  \ 'qjs': 'javascript',
+  \ 'rhino': 'javascript',
+  \ 'v8': 'javascript',
+  \ 'v8-shell': 'javascript',
+  \ 'julia': 'julia',
+  \ 'lua': 'lua',
+  \ 'moon': 'moon',
+  \ 'ocaml': 'ocaml',
+  \ 'ocamlrun': 'ocaml',
+  \ 'ocamlscript': 'ocaml',
+  \ 'cperl': 'perl',
+  \ 'perl': 'perl',
+  \ 'php': 'php',
+  \ 'swipl': 'prolog',
+  \ 'yap': 'prolog',
+  \ 'pwsh': 'ps1',
+  \ 'python': 'python',
+  \ 'python2': 'python',
+  \ 'python3': 'python',
+  \ 'qmake': 'qmake',
+  \ 'Rscript': 'r',
+  \ 'racket': 'racket',
+  \ 'perl6': 'raku',
+  \ 'raku': 'raku',
+  \ 'rakudo': 'raku',
+  \ 'ruby': 'ruby',
+  \ 'macruby': 'ruby',
+  \ 'rake': 'ruby',
+  \ 'jruby': 'ruby',
+  \ 'rbx': 'ruby',
+  \ 'scala': 'scala',
+  \ 'ash': 'sh',
+  \ 'bash': 'sh',
+  \ 'dash': 'sh',
+  \ 'ksh': 'sh',
+  \ 'mksh': 'sh',
+  \ 'pdksh': 'sh',
+  \ 'rc': 'sh',
+  \ 'sh': 'sh',
+  \ 'zsh': 'sh',
+  \ 'boolector': 'smt2',
+  \ 'cvc4': 'smt2',
+  \ 'mathsat5': 'smt2',
+  \ 'opensmt': 'smt2',
+  \ 'smtinterpol': 'smt2',
+  \ 'smt-rat': 'smt2',
+  \ 'stp': 'smt2',
+  \ 'verit': 'smt2',
+  \ 'yices2': 'smt2',
+  \ 'z3': 'smt2',
+  \ 'deno': 'typescript',
+  \ 'ts-node': 'typescript',
+  \ }
\ No newline at end of file
diff --git a/autoload/sleuth.vim b/autoload/polyglot/sleuth.vim
index 3a41f6f9..d74de687 100644
--- a/autoload/sleuth.vim
+++ b/autoload/polyglot/sleuth.vim
@@ -232,6 +232,6 @@ let s:globs = {
   \ 'zsh': '*.zsh,.zshrc,.zshenv,.zlogin,.zprofile,.zlogout,.zlog*,.zcompdump*,.zfbfmarks,.zsh*',
   \}
 
-func! sleuth#GlobForFiletype(type)
+func! polyglot#sleuth#GlobForFiletype(type)
   return get(s:globs, a:type, '')
 endfunc
diff --git a/ftdetect/polyglot.vim b/ftdetect/polyglot.vim
index 0d9fd370..c96760a7 100644
--- a/ftdetect/polyglot.vim
+++ b/ftdetect/polyglot.vim
@@ -128,7 +128,7 @@ if !has_key(s:disabled_packages, 'abap')
 endif
 
 if !has_key(s:disabled_packages, 'abaqus')
-  au! BufNewFile,BufRead *.inp call polyglot#DetectInpFiletype()
+  au! BufNewFile,BufRead *.inp call polyglot#detect#Inp()
 endif
 
 if !has_key(s:disabled_packages, 'abc')
@@ -215,7 +215,7 @@ if !has_key(s:disabled_packages, 'arch')
 endif
 
 if !has_key(s:disabled_packages, 'c/c++')
-  au! BufNewFile,BufRead *.h call polyglot#DetectHFiletype()
+  au! BufNewFile,BufRead *.h call polyglot#detect#H()
   au! BufNewFile,BufRead *.c,*.cats,*.idc,*.qc,*enlightenment/*.cfg set ft=c
   au! BufNewFile,BufRead *.c++,*.cc,*.cp,*.cpp,*.cxx,*.h++,*.hh,*.hpp,*.hxx,*.inc,*.inl,*.ipp,*.moc,*.tcc,*.tlh,*.tpp set ft=cpp
 endif
@@ -249,12 +249,12 @@ if !has_key(s:disabled_packages, 'asn')
 endif
 
 if !has_key(s:disabled_packages, 'aspvbs')
-  au! BufNewFile,BufRead *.asp call polyglot#DetectAspFiletype()
-  au! BufNewFile,BufRead *.asa call polyglot#DetectAsaFiletype()
+  au! BufNewFile,BufRead *.asp call polyglot#detect#Asp()
+  au! BufNewFile,BufRead *.asa call polyglot#detect#Asa()
 endif
 
 if !has_key(s:disabled_packages, 'aspperl')
-  au! BufNewFile,BufRead *.asp call polyglot#DetectAspFiletype()
+  au! BufNewFile,BufRead *.asp call polyglot#detect#Asp()
 endif
 
 if !has_key(s:disabled_packages, 'atlas')
@@ -381,12 +381,12 @@ if !has_key(s:disabled_packages, 'flatbuffers')
 endif
 
 if !has_key(s:disabled_packages, 'forth')
-  au! BufNewFile,BufRead *.fs call polyglot#DetectFsFiletype()
+  au! BufNewFile,BufRead *.fs call polyglot#detect#Fs()
   au! BufNewFile,BufRead *.ft,*.fth set ft=forth
 endif
 
 if !has_key(s:disabled_packages, 'fsharp')
-  au! BufNewFile,BufRead *.fs call polyglot#DetectFsFiletype()
+  au! BufNewFile,BufRead *.fs call polyglot#detect#Fs()
   au! BufNewFile,BufRead *.fsi,*.fsx set ft=fsharp
 endif
 
@@ -403,7 +403,7 @@ if !has_key(s:disabled_packages, 'git')
 endif
 
 if !has_key(s:disabled_packages, 'glsl')
-  au! BufNewFile,BufRead *.fs call polyglot#DetectFsFiletype()
+  au! BufNewFile,BufRead *.fs call polyglot#detect#Fs()
   au! BufNewFile,BufRead *.comp,*.fp,*.frag,*.frg,*.fsh,*.fshader,*.geo,*.geom,*.glsl,*.glslf,*.glslv,*.gs,*.gshader,*.shader,*.tesc,*.tese,*.vert,*.vrx,*.vsh,*.vshader set ft=glsl
 endif
 
@@ -471,7 +471,7 @@ if !has_key(s:disabled_packages, 'hive')
 endif
 
 if !has_key(s:disabled_packages, 'html5')
-  au! BufNewFile,BufRead *.html call polyglot#DetectHtmlFiletype()
+  au! BufNewFile,BufRead *.html call polyglot#detect#Html()
   au! BufNewFile,BufRead *.htm,*.html.hl,*.inc,*.st,*.xht,*.xhtml set ft=html
 endif
 
@@ -484,14 +484,14 @@ if !has_key(s:disabled_packages, 'icalendar')
 endif
 
 if !has_key(s:disabled_packages, 'idris')
-  au! BufNewFile,BufRead *.lidr call polyglot#DetectLidrFiletype()
-  au! BufNewFile,BufRead *.idr call polyglot#DetectIdrFiletype()
+  au! BufNewFile,BufRead *.lidr call polyglot#detect#Lidr()
+  au! BufNewFile,BufRead *.idr call polyglot#detect#Idr()
   au! BufNewFile,BufRead idris-response set ft=idris
 endif
 
 if !has_key(s:disabled_packages, 'idris2')
-  au! BufNewFile,BufRead *.lidr call polyglot#DetectLidrFiletype()
-  au! BufNewFile,BufRead *.idr call polyglot#DetectIdrFiletype()
+  au! BufNewFile,BufRead *.lidr call polyglot#detect#Lidr()
+  au! BufNewFile,BufRead *.idr call polyglot#detect#Idr()
   au! BufNewFile,BufRead *.ipkg,idris-response set ft=idris2
 endif
 
@@ -582,7 +582,7 @@ if !has_key(s:disabled_packages, 'mako')
 endif
 
 if !has_key(s:disabled_packages, 'mathematica')
-  au! BufNewFile,BufRead *.m call polyglot#DetectMFiletype()
+  au! BufNewFile,BufRead *.m call polyglot#detect#M()
   au! BufNewFile,BufRead *.cdf,*.ma,*.mathematica,*.mma,*.mt,*.nb,*.nbp,*.wl,*.wls,*.wlt set ft=mma
 endif
 
@@ -604,7 +604,7 @@ if !has_key(s:disabled_packages, 'moonscript')
 endif
 
 if !has_key(s:disabled_packages, 'murphi')
-  au! BufNewFile,BufRead *.m call polyglot#DetectMFiletype()
+  au! BufNewFile,BufRead *.m call polyglot#detect#M()
 endif
 
 if !has_key(s:disabled_packages, 'nginx')
@@ -622,8 +622,8 @@ if !has_key(s:disabled_packages, 'nix')
 endif
 
 if !has_key(s:disabled_packages, 'objc')
-  au! BufNewFile,BufRead *.m call polyglot#DetectMFiletype()
-  au! BufNewFile,BufRead *.h call polyglot#DetectHFiletype()
+  au! BufNewFile,BufRead *.m call polyglot#detect#M()
+  au! BufNewFile,BufRead *.h call polyglot#detect#H()
 endif
 
 if !has_key(s:disabled_packages, 'ocaml')
@@ -639,7 +639,7 @@ if !has_key(s:disabled_packages, 'ocaml')
 endif
 
 if !has_key(s:disabled_packages, 'octave')
-  au! BufNewFile,BufRead *.m call polyglot#DetectMFiletype()
+  au! BufNewFile,BufRead *.m call polyglot#detect#M()
   au! BufNewFile,BufRead *.oct set ft=octave
 endif
 
@@ -648,10 +648,10 @@ if !has_key(s:disabled_packages, 'opencl')
 endif
 
 if !has_key(s:disabled_packages, 'perl')
-  au! BufNewFile,BufRead *.tt2 call polyglot#DetectTt2Filetype()
-  au! BufNewFile,BufRead *.t call polyglot#DetectTFiletype()
-  au! BufNewFile,BufRead *.pm call polyglot#DetectPmFiletype()
-  au! BufNewFile,BufRead *.pl call polyglot#DetectPlFiletype()
+  au! BufNewFile,BufRead *.tt2 call polyglot#detect#Tt2()
+  au! BufNewFile,BufRead *.t call polyglot#detect#T()
+  au! BufNewFile,BufRead *.pm call polyglot#detect#Pm()
+  au! BufNewFile,BufRead *.pl call polyglot#detect#Pl()
   au! BufNewFile,BufRead *.xs set ft=xs
   au! BufNewFile,BufRead *.comp,*.mason,*.mhtml set ft=mason
   au! BufNewFile,BufRead *.pod set ft=pod
@@ -740,9 +740,9 @@ if !has_key(s:disabled_packages, 'ragel')
 endif
 
 if !has_key(s:disabled_packages, 'raku')
-  au! BufNewFile,BufRead *.t call polyglot#DetectTFiletype()
-  au! BufNewFile,BufRead *.pm call polyglot#DetectPmFiletype()
-  au! BufNewFile,BufRead *.pl call polyglot#DetectPlFiletype()
+  au! BufNewFile,BufRead *.t call polyglot#detect#T()
+  au! BufNewFile,BufRead *.pm call polyglot#detect#Pm()
+  au! BufNewFile,BufRead *.pl call polyglot#detect#Pl()
   au! BufNewFile,BufRead *.6pl,*.6pm,*.nqp,*.p6,*.p6l,*.p6m,*.pl6,*.pm6,*.pod6,*.raku,*.rakudoc,*.rakumod,*.rakutest,*.t6 set ft=raku
 endif
 
@@ -755,7 +755,7 @@ if !has_key(s:disabled_packages, 'razor')
 endif
 
 if !has_key(s:disabled_packages, 'reason')
-  au! BufNewFile,BufRead *.re call polyglot#DetectReFiletype()
+  au! BufNewFile,BufRead *.re call polyglot#detect#Re()
   au! BufNewFile,BufRead *.rei set ft=reason
 endif
 
@@ -949,7 +949,7 @@ if !has_key(s:disabled_packages, 'zig')
 endif
 
 if !has_key(s:disabled_packages, 'trasys')
-  au! BufNewFile,BufRead *.inp call polyglot#DetectInpFiletype()
+  au! BufNewFile,BufRead *.inp call polyglot#detect#Inp()
 endif
 
 if !has_key(s:disabled_packages, 'basic')
@@ -957,7 +957,7 @@ if !has_key(s:disabled_packages, 'basic')
 endif
 
 if !has_key(s:disabled_packages, 'visual-basic')
-  au! BufNewFile,BufRead *.bas call polyglot#DetectBasFiletype()
+  au! BufNewFile,BufRead *.bas call polyglot#detect#Bas()
   au! BufNewFile,BufRead *.cls,*.ctl,*.dsm,*.frm,*.frx,*.sba,*.vba,*.vbs set ft=vb
 endif
 
@@ -976,12 +976,12 @@ if !has_key(s:disabled_packages, 'bzl')
 endif
 
 if !has_key(s:disabled_packages, 'prolog')
-  au! BufNewFile,BufRead *.pl call polyglot#DetectPlFiletype()
+  au! BufNewFile,BufRead *.pl call polyglot#detect#Pl()
   au! BufNewFile,BufRead *.pdb,*.pro,*.prolog,*.yap set ft=prolog
 endif
 
 if !has_key(s:disabled_packages, 'tads')
-  au! BufNewFile,BufRead *.t call polyglot#DetectTFiletype()
+  au! BufNewFile,BufRead *.t call polyglot#detect#T()
 endif
 
 if !has_key(s:disabled_packages, 'gitignore')
@@ -994,11 +994,11 @@ endif
 
 
 
-au! BufNewFile,BufRead,StdinReadPost * if expand("<afile>") !~ g:ft_ignore_pat |
-  \ call polyglot#Shebang() | endif
+au! BufNewFile,BufRead,StdinReadPost * if expand("<afile>:e") == "" |
+  \ call polyglot#shebang#Detect() | endif
 
-au BufEnter * if &ft == "" && expand("<afile>") !~ g:ft_ignore_pat |
-      \ call s:Observe('Shebang') | endif
+au BufEnter * if &ft == "" && expand("<afile>:e") == ""  |
+      \ call s:Observe('shebang#Detect') | endif
 
 augroup END
 
@@ -1125,7 +1125,7 @@ if !has_key(s:disabled_packages, 'autoindent')
     if s:guess(getline(1, 32))
       return
     endif
-    let pattern = sleuth#GlobForFiletype(&filetype)
+    let pattern = polyglot#sleuth#GlobForFiletype(&filetype)
     if len(pattern) == 0
       return
     endif
@@ -1201,4 +1201,5 @@ if exists('g:polyglot_disabled')
 endif
 
 " restore Vi compatibility settings
-let &cpo = s:cpo_save
\ No newline at end of file
+let &cpo = s:cpo_save
+
diff --git a/heuristics.yaml b/heuristics.yaml
index 129734f8..4080cbc4 100644
--- a/heuristics.yaml
+++ b/heuristics.yaml
@@ -132,6 +132,8 @@ rules:
     filetype: perl
 - override: true
 - filetype: perl
+  shebang: true
+  fallback: true
 ---
 extensions: [pl]
 rules:
@@ -149,6 +151,8 @@ rules:
     filetype: perl
 - override: true
 - filetype: perl
+  shebang: true
+  fallback: true
 ---
 extensions: [t]
 rules:
@@ -166,6 +170,8 @@ rules:
   #   filetype: turing
 - override: true
 - filetype: perl
+  shebang: true
+  fallback: true
 ---
 extensions: [tt2]
 rules:
diff --git a/polyglot.vim b/polyglot.vim
index e86e62ef..7c922d09 100644
--- a/polyglot.vim
+++ b/polyglot.vim
@@ -1,15 +1,9 @@
-""" autoload/polyglot.vim
+""" autoload/polyglot/shebang.vim
 
-" Line continuation is used here, remove 'C' from 'cpoptions'
-let s:cpo_save = &cpo
-set cpo&vim
-
-func! polyglot#Shebang()
-  if getline(1) =~# "^#!"
-    let ft = polyglot#ShebangFiletype()
-    if ft != ""
-      let &ft = ft
-    endif
+func! polyglot#shebang#Detect()
+  let ft = s:Filetype()
+  if ft != ""
+    let &ft = ft
   endif
 
   if &ft == ""
@@ -23,7 +17,7 @@ let s:r_hashbang = '^#!\s*\(\S\+\)\s*\(.*\)\s*'
 let s:r_envflag = '%(\S\+=\S\+\|-[iS]\|--ignore-environment\|--split-string\)'
 let s:r_env = '^\%(\' . s:r_envflag . '\s\+\)*\(\S\+\)'
 
-func! polyglot#ShebangFiletype()
+func! s:Filetype()
   let l:line1 = getline(1)
 
   if l:line1 !~# "^#!"
@@ -60,12 +54,6 @@ func! polyglot#ShebangFiletype()
   endfor
 endfunc
 
-" scripts/build generates heuristics functions here
-
-" Restore 'cpoptions'
-let &cpo = s:cpo_save
-unlet s:cpo_save
-
 """ ftdetect/polyglot.vim
 
 " don't spam the user when Vim is started in Vi compatibility mode
@@ -167,11 +155,11 @@ augroup filetypedetect
 
 " scripts/build inserts here filetype detection autocommands
 
-au! BufNewFile,BufRead,StdinReadPost * if expand("<afile>") !~ g:ft_ignore_pat |
-  \ call polyglot#Shebang() | endif
+au! BufNewFile,BufRead,StdinReadPost * if expand("<afile>:e") == "" |
+  \ call polyglot#shebang#Detect() | endif
 
-au BufEnter * if &ft == "" && expand("<afile>") !~ g:ft_ignore_pat |
-      \ call s:Observe('Shebang') | endif
+au BufEnter * if &ft == "" && expand("<afile>:e") == ""  |
+      \ call s:Observe('shebang#Detect') | endif
 
 augroup END
 
@@ -298,7 +286,7 @@ if !has_key(s:disabled_packages, 'autoindent')
     if s:guess(getline(1, 32))
       return
     endif
-    let pattern = sleuth#GlobForFiletype(&filetype)
+    let pattern = polyglot#sleuth#GlobForFiletype(&filetype)
     if len(pattern) == 0
       return
     endif
diff --git a/scripts/build b/scripts/build
index 2e767b9b..3ec5b50c 100755
--- a/scripts/build
+++ b/scripts/build
@@ -13,8 +13,11 @@ Dir.chdir(File.dirname(__dir__))
 BASE_URL = 'https://raw.githubusercontent.com/github/linguist/master'
 
 def read_section(name)
-  "\" Please do not edit this file directly, instead modify polyglot.vim or scripts/build\n\n" +
-  File.read('polyglot.vim').match(/""" #{Regexp.escape(name)}\n*(.*)\n(?=\n""")/m)[1]
+  section = File.read('polyglot.vim').split('""" ').find { |e| e.start_with?(name) }
+  if section.nil?
+    raise StandardError.new("Section not found: #{name}")
+  end
+  "\" Please do not edit this file directly, instead modify polyglot.vim or scripts/build\n" + section[(section.index("\n") + 1)..-1]
 end
 
 def camelize(str)
@@ -390,10 +393,17 @@ def rule_to_code(rule)
     EOS
   end
 
+  if rule.has_key?("shebang")
+    return <<~EOS
+      if polyglot#shebang#Detect() | return | endif
+      #{indent(rule_to_code(except(rule, "shebang")), 0)}
+    EOS
+  end
+
   if rule.has_key?("filetype")
     if rule.has_key?("fallback")
       return <<~EOS
-        set ft=#{rule["filetype"]} | au! BufWritePost <buffer> ++once call polyglot#Detect#{camelize(rule["extensions"].first)}Filetype()
+        set ft=#{rule["filetype"]} | au! BufWritePost <buffer> ++once call polyglot#detect##{camelize(rule["extensions"].first)}()
         return
       EOS
     end
@@ -489,6 +499,8 @@ def extract(packages)
 end
 
 def generate_ftdetect(packages, heuristics)
+  FileUtils.mkdir_p('autoload/polyglot')
+
   output = "\n"
 
   all_filetypes = packages.flat_map { |f| f["filetypes"] || [] }
@@ -561,7 +573,7 @@ def generate_ftdetect(packages, heuristics)
 
     for heuristic in package_heuristics.uniq
       extensions = heuristic["extensions"].map { |e| "*.#{e}" }
-      autocommands << "  au! BufNewFile,BufRead #{extensions.join(",")} call polyglot#Detect#{camelize(heuristic["extensions"].first)}Filetype()\n"
+      autocommands << "  au! BufNewFile,BufRead #{extensions.join(",")} call polyglot#detect##{camelize(heuristic["extensions"].first)}()\n"
     end
 
     if autocommands != ""
@@ -580,6 +592,18 @@ def generate_ftdetect(packages, heuristics)
      ftdetect.gsub('" scripts/build inserts here filetype detection autocommands') { output }
   )
 
+  output = []
+
+  for heuristic in heuristics
+    output << <<~EOS
+      func! polyglot#detect##{camelize(heuristic["extensions"].first)}()
+      #{indent(rules_to_code(heuristic), 2)}
+      endfunc
+    EOS
+  end
+
+  File.write('autoload/polyglot/detect.vim', output.join("\n"))
+
   output = <<~EOS
     let s:interpreters = {
     EOS
@@ -590,24 +614,10 @@ def generate_ftdetect(packages, heuristics)
       end
     end
 
-  output << <<~EOS
-      \\ }
-
-  EOS
-
-  for heuristic in heuristics
-    output << <<~EOS
-      func! polyglot#Detect#{camelize(heuristic["extensions"].first)}Filetype()
-      #{indent(rules_to_code(heuristic), 2)}
-      endfunc
-
-    EOS
-  end
-
-  autoload_script = read_section('autoload/polyglot.vim')
-  autoload_script["\" scripts/build generates heuristics functions here\n"] = output
+  output << "  \\ }"
 
-  File.write('autoload/polyglot.vim', autoload_script)
+  autoload_script = read_section('autoload/polyglot/shebang.vim')
+  File.write('autoload/polyglot/shebang.vim', autoload_script + "\n\n" + output)
 end
 
 def generate_tests(packages)
@@ -744,13 +754,13 @@ def generate_plugins(packages)
 
 
   output << <<~EOS
-    func! sleuth#GlobForFiletype(type)
+    func! polyglot#sleuth#GlobForFiletype(type)
       return get(s:globs, a:type, '')
     endfunc
   EOS
 
 
-  File.write('autoload/sleuth.vim', output)
+  File.write('autoload/polyglot/sleuth.vim', output)
 end
 
 def process_list(list, extras)
diff --git a/tests/extensions.vim b/tests/extensions.vim
index 16548eb8..6492e1ac 100644
--- a/tests/extensions.vim
+++ b/tests/extensions.vim
@@ -30,6 +30,7 @@ call TestExtension("sh", "bash3", "#! /bin/bash2.3")
 call TestExtension("sh", "bash4", "#!/usr/bin/env bash")
 call TestExtension("sh", "bash6", "#!/usr/bin/env -i -=split-string foo=bar bash -l foo")
 call TestExtension("sh", "bash1", "#!/bin/bash")
+call TestExtension("sh", "bash7", ":")
 
 " Vim help file
 call TestExtension("help", $VIMRUNTIME . "/doc/foobar.txt", "")