Editing Allow Inform header files to be distinguished from C headers

{{review}}
{{TipImported
|id=410
|previous=409
|next=411
|created=January 22, 2003
|complexity=intermediate
|author=Stephen Thomas, Ross Presser, Neil Cerruti
|version=6.0
|rating=19/7
|category1=LanguageSpecific
|category2=Filetype
}}
Inform is an Interactive Fiction authoring language. Its header files often use a '.h' extension, which causes Vim to think they are C files, or do not have any extension at all, leaving Vim unable to determine what kind of file they are. This is irritating to Inform developers using Vim with syntax highlighting.

The solution is to use a custom [[filetype.vim]] and 'scripts.vim'.

In filetype.vim add:
<pre>
au BufNewFile,BufRead *.h call FTCheck_inform()
</pre>

and after <code>augroup END</code> add
<pre>
" function to detect inform code (any extension)
fun! FTCheck_inform()
  if getline(1) =~ "^!"
    setfiletype inform
  elseif getline(2) =~ "^!"
    setfiletype inform
  else
    let s:colnum = col('.')
    let s:linenum = line('.')
    call cursor(500, 1)
    if search('\[\(\s*\I\i*\)*\s*;', 'bW') > 0
      setfiletype inform
    endif
    call cursor(s:linenum, s:colnum)
  endif
endfun
</pre>

On loading a file with a '.h' extension, a function is called to examine the file for certain Inform-specific constructs. If it finds any, it sets the filetype as inform, otherwise it leaves the filetype unset, allowing the global filetype.vim to determine the filetype.

For files with no extension, create a '$HOME/.vim/scripts.vim':
<pre>
" local scripts.vim gets called when
" all autocommands have failed to identify file type,
" but before global scripts.vim
"
call FTCheck_inform()
</pre>

See also the site http://www.stephenthomas.uklinux.net/informvim

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