1 (* Copyright (C) 2004-2005, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
7 * HELM is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
12 * HELM is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with HELM; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 * For details, see the HELM World-Wide-Web page,
23 * http://helm.cs.unibo.it/
28 exception Value_not_found of string
32 | StringValue of string
34 | OptValue of value option
35 | ListValue of value list
41 | OptType of value_type
42 | ListType of value_type
44 type declaration = string * value_type
45 type binding = string * (value_type * value)
46 type t = (string * (value_type * value)) list
48 let lookup_value env name =
50 snd (List.assoc name env)
51 with Not_found -> raise (Value_not_found name)
53 let lookup_term env name =
54 match lookup_value env name with
56 | _ -> raise (Value_not_found name)
58 let lookup_num env name =
59 match lookup_value env name with
61 | _ -> raise (Value_not_found name)
63 let lookup_string env name =
64 match lookup_value env name with
66 | _ -> raise (Value_not_found name)
68 let opt_binding_some (n, (ty, v)) = (n, (OptType ty, OptValue (Some v)))
69 let opt_binding_none (n, (ty, v)) = (n, (OptType ty, OptValue None))
70 let opt_binding_of_name (n, ty) = (n, (OptType ty, OptValue None))
71 let list_binding_of_name (n, ty) = (n, (ListType ty, ListValue []))
72 let opt_declaration (n, ty) = (n, OptType ty)
73 let list_declaration (n, ty) = (n, ListType ty)
75 let declaration_of_var = function
76 | NumVar s -> s, NumType
77 | IdentVar s -> s, StringType
78 | TermVar s -> s, TermType
81 let value_of_term = function
82 | Num (s, _) -> NumValue s
83 | Ident (s, None) -> StringValue s
86 let term_of_value = function
87 | NumValue s -> Num (s, 0)
88 | StringValue s -> Ident (s, None)
90 | _ -> assert false (* TO BE UNDERSTOOD *)
92 let rec well_typed ty value =
94 | TermType, TermValue _
95 | StringType, StringValue _
96 | OptType _, OptValue None
97 | NumType, NumValue _ -> true
98 | OptType ty', OptValue (Some value') -> well_typed ty' value'
99 | ListType ty', ListValue vl ->
100 List.for_all (fun value' -> well_typed ty' value') vl