(* 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/
*)
let debug = true
let debug_print s =
if debug then begin
prerr_endline "";
prerr_endline s;
prerr_endline ""
end
let grammar = Grammar.gcreate Lexer.lex
let term = Grammar.Entry.create grammar "term"
(* let tactic = Grammar.Entry.create grammar "tactic" *)
(* let tactical = Grammar.Entry.create grammar "tactical" *)
let return_term loc term = Ast.LocatedTerm (loc, term)
(* let return_term loc term = term *)
let fail (x, y) msg =
failwith (Printf.sprintf "Error at characters %d - %d: %s" x y msg)
EXTEND
GLOBAL: term;
meta_subst: [
[ s = SYMBOL "_" -> None
| t = term -> Some t ]
];
binder: [
[ SYMBOL <:unicode> (* λ *) -> `Lambda
| SYMBOL <:unicode> (* π *) -> `Pi
| SYMBOL <:unicode> (* ∃ *) -> `Exists
| SYMBOL <:unicode> (* ∀ *) -> `Forall
]
];
substituted_name: [ (* a subs.name is an explicit substitution subject *)
[ s = [ IDENT | SYMBOL ];
subst = OPT [
SYMBOL "\subst"; (* to avoid catching frequent "a [1]" cases *)
LPAREN "[";
substs = LIST1 [
i = IDENT; SYMBOL <:unicode> (* ≔ *); t = term -> (i, t)
] SEP SYMBOL ";";
RPAREN "]" ->
substs
] ->
(match subst with
| Some l -> Ast.Ident (s, l)
| None -> Ast.Ident (s, []))
]
];
name: [ (* as substituted_name with no explicit substitution *)
[ s = [ IDENT | SYMBOL ] -> s ]
];
pattern: [
[ n = name -> [n]
| LPAREN "("; names = LIST1 name; RPAREN ")" -> names ]
];
term:
[ "arrow" RIGHTA
[ t1 = term; SYMBOL <:unicode>; t2 = term ->
return_term loc (Ast.Binder (`Pi, Cic.Anonymous, Some t1, t2))
]
| "eq" LEFTA
[ t1 = term; SYMBOL "="; t2 = term ->
return_term loc (Ast.Appl_symbol ("eq", 0, [t1; t2]))
]
| "add" LEFTA [ (* nothing here by default *) ]
| "mult" LEFTA [ (* nothing here by default *) ]
| "inv" NONA [ (* nothing here by default *) ]
| "simple" NONA
[
(* TODO handle "_" *)
b = binder; vars = LIST1 IDENT SEP SYMBOL ",";
typ = OPT [ SYMBOL ":"; t = term -> t ];
SYMBOL "."; body = term ->
let binder =
List.fold_right
(fun var body -> Ast.Binder (b, Cic.Name var, typ, body))
vars body
in
return_term loc binder
| sort_kind = [
"Prop" -> `Prop | "Set" -> `Set | "Type" -> `Type | "CProp" -> `CProp
] ->
Ast.Sort sort_kind
| n = substituted_name -> return_term loc n
| LPAREN "("; head = term; args = LIST1 term; RPAREN ")" ->
return_term loc (Ast.Appl (head :: args))
| i = NUM -> return_term loc (Ast.Num (i, 0))
(* | i = NUM -> return_term loc (Ast.Num (i, Random.int max_int)) *)
| m = META;
substs = [
LPAREN "["; substs = LIST0 meta_subst SEP SYMBOL ";" ; RPAREN "]" ->
substs
] ->
let index =
try
int_of_string (String.sub m 1 (String.length m - 1))
with Failure "int_of_string" ->
fail loc ("Invalid meta variable number: " ^ m)
in
return_term loc (Ast.Meta (index, substs))
(* actually "in" and "and" are _not_ keywords. Parsing works anyway
* since applications are required to be bound by parens *)
| "let"; name = IDENT; SYMBOL <:unicode> (* ≝ *); t1 = term;
IDENT "in"; t2 = term ->
return_term loc (Ast.LetIn (name, t1, t2))
| "let"; ind_kind = [ "corec" -> `CoInductive | "rec"-> `Inductive ];
defs = LIST1 [
name = IDENT;
index = OPT [ LPAREN "("; index = INT; RPAREN ")" ->
int_of_string index
];
typ = OPT [ SYMBOL ":"; typ = term -> typ ];
SYMBOL <:unicode> (* ≝ *); t1 = term ->
(name, t1, typ, (match index with None -> 1 | Some i -> i))
] SEP (IDENT "and");
IDENT "in"; body = term ->
return_term loc (Ast.LetRec (ind_kind, defs, body))
| outtyp = OPT [ LPAREN "["; typ = term; RPAREN "]" -> typ ];
"match"; t = term;
SYMBOL ":"; indty = IDENT;
"with";
LPAREN "[";
patterns = LIST0 [
p = pattern; SYMBOL <:unicode> (* ⇒ *); t = term -> (p, t)
] SEP SYMBOL "|";
RPAREN "]" ->
return_term loc (Ast.Case (t, indty, outtyp, patterns))
| LPAREN "("; t = term; RPAREN ")" -> return_term loc t
]
];
END
let parse_term = Grammar.Entry.parse term