syn clear

" Just about anything in Twelf is a keyword character
set iskeyword+=@,!,#-',*-45,47-57,59-90,94-122,\|,^:


if &background == "dark"
else
  hi twelfPercentKeyFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=MediumPurple guibg=NONE
  hi twelfTypeFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=orange guibg=NONE
  hi twelfCommentFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=ForestGreen guibg=NONE
  hi twelfSymbolFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=DarkGrey guibg=NONE
  hi twelfPunctuationFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=Blue guibg=NONE
  hi twelfDeclarationFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=FireBrick guibg=NONE
  hi twelfFreeVariableFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=Seagreen guibg=NONE
  hi twelfCurlyFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=gold guibg=NONE
  hi twelfSquareFace term=NONE cterm=NONE ctermfg=Green ctermbg=NONE gui=NONE guifg=purple guibg=NONE
endif

syn keyword twelfPercentKey %mode %infix %prefix %abbrev %postfix %name %freeze %clause %define %solve %querytabled %query %tabled %deterministic %unique %block %worlds %covers %total %terminates %reduces %theorem %prove %assert %establish %sig %struct %where %include %open %use

syn keyword twelfType type
syn match twelfPunct ":\|\.\|="
syn match twelfFVar "\<[A-Z_]\k*\>"  
syn keyword twelfSymbol -> <-
syn match twelfDecl "^\s*[^A-Z_]\k*\s*:" contains=twelfPunct


syn match twelfCurly "{\|}" contained
syn match twelfSquare "\[\|\]" contained
syn match twelfBindDecl "[^A-Z_{\[]\k*\s*:" contains=twelfPunct contained
syn region twelfPiBind start="{" end="}" keepend transparent contains=twelfCurly,twelfPunct,twelfFVar,twelfSymbol,twelfType,twelfBindDecl
syn region twelfLamBind start="\[" end="\]" keepend transparent contains=twelfSquare,twelfPunct,twelfFVar,twelfSymbol,twelfType,twelfBindDecl

"syn region twelfCommand start="^" end="\." keepend transparent contains=ALL

syn match twelfParen "(\|)" contained
syn region twelfParens start="(" end=")" transparent contains=ALL


" Comments hilighting 
"  single line, empty line comments
syn match twelfComment  "% .*\|%%.*\|%$"
"  delimited comments, needs to contain itself to properly hilight nested
"  comments 
syn region twelfDelimitedComment  start="%{" end="}%" contains=twelfDelimitedComment 

" Assign coloration
hi link twelfType              twelfTypeFace
hi link twelfPercentKey        twelfPercentKeyFace
hi link twelfComment           twelfCommentFace
hi link twelfDelimitedComment  twelfCommentFace
hi link twelfSymbol            twelfSymbolFace
hi link twelfPunct             twelfPunctuationFace
hi link twelfParen             twelfSymbolFace
hi link twelfDecl              twelfDeclarationFace
hi link twelfBindDecl          twelfDeclarationFace
hi link twelfFVar              twelfFreeVariableFace
hi link twelfCurly             twelfCurlyFace
hi link twelfSquare            twelfSquareFace

" Indentation

" Folds
"syn region myFold start="%{" end="}%" transparent fold 
"syn sync fromstart

set foldmethod=syntax
set foldminlines=3
" Set the current syntax name
let b:current_syntax = "twelf"