runtime/syntax/xpm.vim

" Vim syntax file
" Language:	X Pixmap
" Maintainer:	Ronald Schild <rs@scutum.de>
" Last Change:	2021 Oct 04
" Version:	5.4n.1
"               Jemma Nelson added termguicolors support
"               Dominique Pellé fixed spelling support

" quit when a syntax file was already loaded
if exists("b:current_syntax")
  finish
endif

syn spell notoplevel

syn keyword xpmType		char
syn keyword xpmStorageClass	static
syn keyword xpmTodo		TODO FIXME XXX  contained
syn region  xpmComment		start="/\*"  end="\*/"  contains=xpmTodo,@Spell
syn region  xpmPixelString	start=+"+  skip=+\\\\\|\\"+  end=+"+  contains=@xpmColors

if has("gui_running") || has("termguicolors") && &termguicolors

let color  = ""
let chars  = ""
let colors = 0
let cpp    = 0
let n      = 0
let i      = 1

while i <= line("$")		" scanning all lines

   let s = matchstr(getline(i), '".\{-1,}"')
   if s != ""			" does line contain a string?

      if n == 0			" first string is the Values string

	 " get the 3rd value: colors = number of colors
	 let colors = substitute(s, '"\s*\d\+\s\+\d\+\s\+\(\d\+\).*"', '\1', '')
	 " get the 4th value: cpp = number of character per pixel
	 let cpp = substitute(s, '"\s*\d\+\s\+\d\+\s\+\d\+\s\+\(\d\+\).*"', '\1', '')
	 if cpp =~ '[^0-9]'
	    break  " if cpp is not made of digits there must be something wrong
	 endif

	 " Highlight the Values string as normal string (no pixel string).
	 " Only when there is no slash, it would terminate the pattern.
	 if s !~ '/'
	    exe 'syn match xpmValues /' . s . '/'
	 endif
	 hi link xpmValues String

	 let n = 1		" n = color index

      elseif n <= colors	" string is a color specification

	 " get chars = <cpp> length string representing the pixels
	 " (first incl. the following whitespace)
	 let chars = substitute(s, '"\(.\{'.cpp.'}\s\).*"', '\1', '')

	 " now get color, first try 'c' key if any (color visual)
	 let color = substitute(s, '".*\sc\s\+\(.\{-}\)\s*\(\(g4\=\|[ms]\)\s.*\)*\s*"', '\1', '')
	 if color == s
	    " no 'c' key, try 'g' key (grayscale with more than 4 levels)
	    let color = substitute(s, '".*\sg\s\+\(.\{-}\)\s*\(\(g4\|[ms]\)\s.*\)*\s*"', '\1', '')
	    if color == s
	       " next try: 'g4' key (4-level grayscale)
	       let color = substitute(s, '".*\sg4\s\+\(.\{-}\)\s*\([ms]\s.*\)*\s*"', '\1', '')
	       if color == s
		  " finally try 'm' key (mono visual)
		  let color = substitute(s, '".*\sm\s\+\(.\{-}\)\s*\(s\s.*\)*\s*"', '\1', '')
		  if color == s
		     let color = ""
		  endif
	       endif
	    endif
	 endif

	 " Vim cannot handle RGB codes with more than 6 hex digits
	 if color =~ '#\x\{10,}$'
	    let color = substitute(color, '\(\x\x\)\x\x', '\1', 'g')
	 elseif color =~ '#\x\{7,}$'
	    let color = substitute(color, '\(\x\x\)\x', '\1', 'g')
	 " nor with 3 digits
	 elseif color =~ '#\x\{3}$'
	    let color = substitute(color, '\(\x\)\(\x\)\(\x\)', '0\10\20\3', '')
	 endif

	 " escape meta characters in patterns
	 let s = escape(s, '/\*^$.~[]')
	 let chars = escape(chars, '/\*^$.~[]')

	 " now create syntax items
	 " highlight the color string as normal string (no pixel string)
	 exe 'syn match xpmCol'.n.'Def /'.s.'/ contains=xpmCol'.n.'inDef'
	 exe 'hi link xpmCol'.n.'Def String'

	 " but highlight the first whitespace after chars in its color
	 exe 'syn match xpmCol'.n.'inDef /"'.chars.'/hs=s+'.(cpp+1).' contained'
	 exe 'hi link xpmCol'.n.'inDef xpmColor'.n

	 " remove the following whitespace from chars
	 let chars = substitute(chars, '.$', '', '')

	 " and create the syntax item contained in the pixel strings
	 exe 'syn match xpmColor'.n.' /'.chars.'/ contained'
	 exe 'syn cluster xpmColors add=xpmColor'.n

	 " if no color or color = "None" show background
	 if color == ""  ||  substitute(color, '.*', '\L&', '') == 'none'
	    exe 'hi xpmColor'.n.' guifg=bg'
	    exe 'hi xpmColor'.n.' guibg=NONE'
	 elseif color !~ "'"
	    exe 'hi xpmColor'.n." guifg='".color."'"
	    exe 'hi xpmColor'.n." guibg='".color."'"
	 endif
	 let n = n + 1
      else
	 break		" no more color string
      endif
   endif
   let i = i + 1
endwhile

unlet color chars colors cpp n i s

endif          " has("gui_running") || has("termguicolors") && &termguicolors

" Define the default highlighting.
" Only when an item doesn't have highlighting yet

hi def link xpmType		Type
hi def link xpmStorageClass	StorageClass
hi def link xpmTodo		Todo
hi def link xpmComment		Comment
hi def link xpmPixelString	String


let b:current_syntax = "xpm"

" vim: ts=8:sw=3:noet: