(* Copyright (C) 2004, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * HELM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://helm.cs.unibo.it/
 *)

open CicTextualParser2Ast
open CicTextualParser2

(*
let i = ref max_int
let get_i () = decr i; !i
*)

EXTEND
  term: LEVEL "add"
    [
      [ t1 = term; SYMBOL "+"; t2 = term ->
          return_term loc (Appl_symbol ("plus", 0, [t1; t2]))
      | t1 = term; SYMBOL "-"; t2 = term ->
          return_term loc (Appl_symbol ("minus", 0, [t1; t2]))
      ]
    ];
  term: LEVEL "mult"
    [
      [ t1 = term; SYMBOL "*"; t2 = term ->
          return_term loc (Appl_symbol ("times", 0, [t1; t2]))
      | t1 = term; SYMBOL "/"; t2 = term ->
          return_term loc (Appl_symbol ("div", 0, [t1; t2]))
      ]
    ];
  term: LEVEL "inv"
    [
      [ SYMBOL "-"; t = term ->
        return_term loc (Appl_symbol ("uminus", 0, [t]))
      ]
    ];
END

let _ =
  DisambiguateChoices.add_num_choice
    ("natural number",
      (fun _ num _ -> HelmLibraryObjects.build_nat (int_of_string num)));
  DisambiguateChoices.add_num_choice
    ("real number",
      (fun _ num _ -> HelmLibraryObjects.build_real (int_of_string num)));
  DisambiguateChoices.add_symbol_choice "plus"
    ("natural plus",
     (fun env _ args ->
       let t1, t2 =
         match args with
         | [t1; t2] -> t1, t2
         | _ -> raise DisambiguateChoices.Invalid_choice
       in
       Cic.Appl [ HelmLibraryObjects.Peano.plus; t1; t2 ]));
  DisambiguateChoices.add_symbol_choice "plus"
    ("real plus",
     (fun env _ args ->
       let t1, t2 =
         match args with
         | [t1; t2] -> t1, t2
         | _ -> raise DisambiguateChoices.Invalid_choice
       in
       Cic.Appl [ HelmLibraryObjects.Reals.rplus; t1; t2 ]));