(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

(*i camlp4deps: "parsing/grammar.cma" i*)

(* $Id: extraargs.ml4,v 1.5.2.1 2004/07/16 19:30:53 herbelin Exp $ *)

open Pp
open Pcoq
open Genarg

(* Rewriting orientation *)

let _ = Metasyntax.add_token_obj "<-"
let _ = Metasyntax.add_token_obj "->"

let pr_orient _prc _prt = function
  | true -> Pp.mt ()
  | false -> Pp.str " <-"

ARGUMENT EXTEND orient TYPED AS bool PRINTED BY pr_orient
| [ "->" ] -> [ true ]
| [ "<-" ] -> [ false ]
| [ ] -> [ true ]
END