(* 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

module Level1Lexer =
struct
  type te = string * string
  let lexer = CicNotationLexer.syntax_pattern_lexer
end
module Level1Parser = Grammar.GMake (Level1Lexer)

module Level2Lexer =
struct
  type te = string * string
  let lexer = CicNotationLexer.ast_pattern_lexer
end
module Level2Parser = Grammar.GMake (Level2Lexer)

module Level3Lexer =
struct
  type te = string * string
  let lexer = CicNotationLexer.ast_pattern_lexer
end
module Level3Parser = Grammar.GMake (Level3Lexer)

let level1_pattern = Level1Parser.Entry.create "level1_pattern"
let level2_pattern = Level2Parser.Entry.create "level2_pattern"
let level3_interpretation = Level3Parser.Entry.create "level3_interpretation"

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)

(* {{{ Grammar for concrete syntax patterns, notation level 1 *)
GEXTEND Level1Parser
  GLOBAL: level1_pattern;
  level1_pattern: [ [ 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_pattern: [
    [ SYMBOL "\\HBOX"; p = simple_pattern -> ()
    | SYMBOL "\\VBOX"; p = simple_pattern -> ()
    | SYMBOL "\\BREAK" -> ()
    ]
  ];
  magic_pattern: [
    [ SYMBOL "\\LIST0"; p = simple_pattern; sep = OPT sep -> ()
    | SYMBOL "\\LIST1"; p = simple_pattern; sep = OPT sep -> ()
    | SYMBOL "\\OPT"; p = simple_pattern -> ()
    ]
  ];
  pattern_variable: [
    [ id = IDENT -> ()
    | SYMBOL "\\NUM"; id = IDENT -> ()
    | SYMBOL "\\IDENT"; id = IDENT -> ()
    ]
  ];
  simple_pattern:
    [ "layout" LEFTA
      [ p1 = SELF; SYMBOL "\\SUB"; p2 = SELF -> ()
      | p1 = SELF; SYMBOL "\\SUP"; p2 = SELF -> ()
      | p1 = SELF; SYMBOL "\\BELOW"; p2 = SELF -> ()
      | p1 = SELF; SYMBOL "\\ABOVE"; p2 = SELF -> ()
      | SYMBOL "["; p1 = pattern; SYMBOL "\\OVER"; p2 = pattern; SYMBOL "]" ->
          ()
      | SYMBOL "["; p1 = pattern; SYMBOL "\\ATOP"; p2 = pattern; SYMBOL "]" ->
          ()
      | SYMBOL "\\ARRAY"; p = SELF; fsep = OPT field_sep; rsep = OPT row_sep ->
          ()
      | SYMBOL "\\FRAC"; p1 = SELF; p2 = SELF -> ()
      | SYMBOL "\\SQRT"; p = SELF -> ()
      | SYMBOL "\\ROOT"; arg = pattern; SYMBOL "\\OF"; index = SELF -> ()
      ]
    | "simple" NONA
      [ m = magic_pattern -> ()
      | v = pattern_variable -> ()
      | b = box_pattern -> ()
      | n = NUMBER -> ()
      | SYMBOL "["; p = pattern; SYMBOL "]" -> ()
      ]
    ];
END
(* }}} *)

(* {{{ Grammar for ast patterns, notation level 2 *)
GEXTEND Level2Parser
  GLOBAL: level2_pattern;
  level2_pattern: [ [ p = pattern -> () ] ];
  sort: [
    [ SYMBOL "\\PROP" -> ()
    | SYMBOL "\\SET" -> ()
    | SYMBOL "\\TYPE" -> ()
    ]
  ];
  explicit_subst: [
    [ (* TODO explicit substitution *)
    ]
  ];
  meta_subst: [
    [ (* TODO meta substitution *)
    ]
  ];
  possibly_typed_name: [
    [ SYMBOL "("; i = IDENT; SYMBOL ":"; typ = pattern; SYMBOL ")" -> ()
    | i = IDENT -> ()
    ]
  ];
  match_pattern: [
    [ n = IDENT -> ()
    | SYMBOL "("; head = IDENT; vars = LIST1 possibly_typed_name; SYMBOL ")" ->
        ()
    ]
  ];
  binder: [
    [ SYMBOL <:unicode<Pi>>     (* Π *) -> ()
    | SYMBOL <:unicode<exists>> (* ∃ *) -> ()
    | SYMBOL <:unicode<forall>> (* ∀ *) -> ()
    | SYMBOL <:unicode<lambda>> (* λ *) -> ()
    ]
  ];
  bound_names: [
    [ vars = LIST1 IDENT SEP SYMBOL ",";
      typ = OPT [ SYMBOL ":"; p = pattern -> () ] -> ()
    | LIST1 [
        SYMBOL "("; vars = LIST1 IDENT SEP SYMBOL ",";
        typ = OPT [ SYMBOL ":"; p = pattern -> () ]; SYMBOL ")" -> ()
      ] ->
        ()
    ]
  ];
  induction_kind: [
    [ IDENT "rec" -> ()
    | IDENT "corec" -> ()
    ]
  ];
  let_defs: [
    [ defs = LIST1 [
        name = IDENT; args = bound_names;
        index_name = OPT [ IDENT "on"; idx = IDENT -> () ];
        ty = OPT [ SYMBOL ":" ; p = pattern -> () ];
        SYMBOL <:unicode<def>> (* ≝ *); body = pattern ->
          ()
      ] SEP IDENT "and" ->
        ()
    ]
  ];
  pattern_variable: [
    [ SYMBOL "\\NUM"; id = IDENT -> ()
    | SYMBOL "\\IDENT"; id = IDENT -> ()
    | SYMBOL "\\FRESH"; id = IDENT -> ()
    ]
  ];
  magic_pattern: [
    [ SYMBOL "\\FOLD"; n = OPT NUMBER; [ IDENT "left" | IDENT "right" ];
      LIST1 IDENT; SYMBOL "."; p1 = pattern;
      OPT [ SYMBOL "\\LAMBDA"; LIST1 IDENT ]; p2 = pattern ->
        ()
    | SYMBOL "\\DEFAULT"; id = IDENT; p1 = pattern; p2 = pattern -> ()
    ]
  ];
  pattern:
    [ "letin" NONA
      [ IDENT "let"; var = possibly_typed_name; SYMBOL <:unicode<def>> (* ≝ *);
        p1 = pattern; "in"; p2 = pattern ->
          ()
      | IDENT "let"; k = induction_kind; defs = let_defs; IDENT "in";
        body = pattern ->
          ()
      ]
    | "binder" RIGHTA
      [ b = binder; bound_names; SYMBOL "."; body = pattern -> () ]
    | "extension"
      [ ]
    | "apply" LEFTA
      [ p1 = pattern; p2 = pattern -> () ]
    | "simple" NONA
      [ i = IDENT -> ()
      | i = IDENT; s = explicit_subst -> ()
      | n = NUMBER -> ()
      | IMPLICIT -> ()
      | m = META -> ()
      | m = META; s = meta_subst -> ()
      | s = sort -> ()
      | s = SYMBOL -> ()
      | u = URI -> ()
      | outtyp = OPT [ SYMBOL "["; typ = pattern; SYMBOL "]" ];
        IDENT "match"; t = pattern;
        indty_ident = OPT [ SYMBOL ":"; id = IDENT ];
        IDENT "with"; SYMBOL "[";
        patterns = LIST0 [
          lhs = match_pattern; SYMBOL <:unicode<Rightarrow>> (* ⇒ *);
          rhs = pattern ->
            ()
        ] SEP SYMBOL "|";
        SYMBOL "]" ->
          ()
      | SYMBOL "("; p1 = pattern; SYMBOL ":"; p2 = pattern; SYMBOL ")" -> ()
      | SYMBOL "("; p = pattern; SYMBOL ")" -> ()
      | v = pattern_variable -> ()
      | m = magic_pattern -> ()
      ]
    ];
END
(* }}} *)

(* {{{ Grammar for interpretation, notation level 3 *)
GEXTEND Level3Parser
  GLOBAL: level3_interpretation;
  level3_interpretation: [ [ i = interpretation -> () ] ];
  argument: [
    [ i = IDENT -> ()
    | SYMBOL <:unicode<eta>> (* η *); SYMBOL "."; a = SELF -> ()
    | SYMBOL <:unicode<eta>> (* η *); i = IDENT; SYMBOL "."; a = SELF -> ()
    ]
  ];
  term: [
    [ u = URI -> ()
    | a = argument -> ()
    | SYMBOL "("; terms = LIST1 SELF; SYMBOL ")" -> ()
    ]
  ];
  interpretation: [
    [ IDENT "interpretation"; s = SYMBOL; args = LIST1 argument; IDENT "as";
      t = term ->
        ()
    ]
  ];
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_syntax_pattern stream =
  exc_located_wrapper
    (fun () ->
      (Level1Parser.Entry.parse level1_pattern (Level1Parser.parsable stream)))

let parse_ast_pattern stream =
  exc_located_wrapper
    (fun () ->
      (Level2Parser.Entry.parse level2_pattern (Level2Parser.parsable stream)))

let parse_interpretation stream =
  exc_located_wrapper
    (fun () ->
      (Level3Parser.Entry.parse level3_interpretation
        (Level3Parser.parsable stream)))

(* vim:set encoding=utf8 foldmethod=marker: *)