(* Copyright (C) 2005, 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 Printf

exception Parse_error of Token.flocation * string

let grammar = Grammar.gcreate CicNotationLexer.level1_lexer

let level1 = Grammar.Entry.create grammar "level1"

let return_term loc term = ()

(*let fail floc msg =*)
(*  let (x, y) = CicAst.loc_of_floc floc in*)
(*  failwith (sprintf "Error at characters %d - %d: %s" x y msg)*)

let int_of_string s =
  try
    Pervasives.int_of_string s
  with Failure _ ->
    failwith (sprintf "Lexer failure: string_of_int \"%s\" failed" s)

EXTEND
  GLOBAL: level1;

  level1: [ [ p = pattern -> () ] ];

  pattern: [ [ p = LIST1 simple_pattern -> () ] ];

  literal: [
    [ s = SYMBOL -> ()
    | k = KEYWORD -> ()
    ]
  ];

  sep:       [ [ SYMBOL "\\SEP";      sep = literal -> () ] ];
  row_sep:   [ [ SYMBOL "\\ROWSEP";   sep = literal -> () ] ];
  field_sep: [ [ SYMBOL "\\FIELDSEP"; sep = literal -> () ] ];

  box_token: [
    [ SYMBOL "\\HBOX"; p = simple_pattern -> ()
    | SYMBOL "\\VBOX"; p = simple_pattern -> ()
    | SYMBOL "\\BREAK" -> ()
    ]
  ];

  layout_schemata: [
    [ SYMBOL "\\ARRAY"; p = simple_pattern; fsep = OPT field_sep;
      rsep = OPT row_sep ->
        ()
    | SYMBOL "\\FRAC"; p1 = simple_pattern; p2 = simple_pattern -> ()
    | SYMBOL "\\SQRT"; p = simple_pattern -> ()
    | SYMBOL "\\ROOT"; p1 = simple_pattern; SYMBOL "\\OF";
      p2 = simple_pattern ->
        ()
     (* TODO XXX many issues here:
      * - "^^" is lexed as two "^" symbols
      * - "a_b" is lexed as IDENT "a_b" *)
    | p1 = simple_pattern; SYMBOL "^"; p2 = simple_pattern -> ()
    | p1 = simple_pattern; SYMBOL "^"; SYMBOL "^"; p2 = simple_pattern -> ()
    | p1 = simple_pattern; SYMBOL "_"; p2 = simple_pattern -> ()
    | p1 = simple_pattern; SYMBOL "_"; SYMBOL "_"; p2 = simple_pattern -> ()
    ]
  ];

  simple_pattern: [
    [ SYMBOL "\\LIST0"; p = simple_pattern; sep = OPT sep -> ()
    | SYMBOL "\\LIST1"; p = simple_pattern; sep = OPT sep -> ()
    | b = box_token -> ()
    | id = IDENT -> ()
    | SYMBOL "\\NUM"; id = IDENT -> ()
    | SYMBOL "\\IDENT"; id = IDENT -> ()
    | SYMBOL "\\OPT"; p = simple_pattern -> ()
    | l = layout_schemata -> ()
    | SYMBOL "["; p = pattern; SYMBOL "]" -> ()
    ]
  ];
END

let exc_located_wrapper f =
  try
    f ()
  with
  | Stdpp.Exc_located (floc, Stream.Error msg) ->
      raise (Parse_error (floc, msg))
  | Stdpp.Exc_located (floc, exn) ->
      raise (Parse_error (floc, (Printexc.to_string exn)))

let parse_level1_pattern stream =
  exc_located_wrapper (fun () -> (Grammar.Entry.parse level1 stream))

(* vim:set encoding=utf8: *)