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/
29 (* TODO ensure that names generated by fresh_var do not clash with user's *)
31 let index = ref ~-1 in
34 "fresh" ^ string_of_int !index
36 let meta_names_of term =
37 let rec names = ref [] in
39 if List.mem n !names then ()
40 else names := n :: !names
42 let rec aux = function
43 | AttributedTerm (_, term) -> aux term
44 | Appl terms -> List.iter aux terms
45 | Binder (_, _, body) -> aux body
46 | Case (term, indty, outty_opt, patterns) ->
49 List.iter aux_branch patterns
50 | LetIn (_, t1, t2) ->
53 | LetRec (_, definitions, body) ->
54 List.iter aux_definition definitions ;
56 | Uri (_, Some substs) -> aux_substs substs
57 | Ident (_, Some substs) -> aux_substs substs
58 | Meta (_, substs) -> aux_meta_substs substs
68 | Magic magic -> aux_magic magic
69 | Variable var -> aux_variable var
72 and aux_opt = function
73 | Some term -> aux term
75 and aux_capture_var (_, ty_opt) = aux_opt ty_opt
76 and aux_branch (pattern, term) =
79 and aux_pattern (head, vars) =
80 List.iter aux_capture_var vars
81 and aux_definition (var, term, i) =
84 and aux_substs substs = List.iter (fun (_, term) -> aux term) substs
85 and aux_meta_substs meta_substs = List.iter aux_opt meta_substs
86 and aux_variable = function
87 | NumVar name -> add_name name
88 | IdentVar name -> add_name name
89 | TermVar name -> add_name name
91 | Ascription _ -> assert false
92 and aux_magic = function
94 | Fold (_, t1, _, t2) ->
102 let unopt_names names env =
103 let rec aux acc = function
104 | (name, (ty, v)) :: tl when List.mem name names ->
106 | OptType ty, OptValue (Some v) -> aux ((name, (ty, v)) :: acc) tl
108 | _ :: tl -> aux acc tl
109 (* some pattern may contain only meta names, thus we trash all others *)
114 let head_names names env =
115 let rec aux acc = function
116 | (name, (ty, v)) :: tl when List.mem name names ->
118 | ListType ty, ListValue (v :: _) -> aux ((name, (ty, v)) :: acc) tl
120 | _ :: tl -> aux acc tl
121 (* base pattern may contain only meta names, thus we trash all others *)
126 let tail_names names env =
127 let rec aux acc = function
128 | (name, (ty, v)) :: tl when List.mem name names ->
130 | ListType ty, ListValue (_ :: vtl) ->
131 aux ((name, (ListType ty, ListValue vtl)) :: acc) tl
133 | binding :: tl -> aux (binding :: acc) tl
138 let instantiate_level2 env term =
139 let fresh_env = ref [] in
140 let lookup_fresh_name n =
142 List.assoc n !fresh_env
144 let new_name = fresh_var () in
145 fresh_env := (n, new_name) :: !fresh_env;
148 let rec aux env term =
150 | AttributedTerm (_, term) -> aux env term
151 | Appl terms -> Appl (List.map (aux env) terms)
152 | Binder (binder, var, body) ->
153 Binder (binder, aux_capture_var env var, aux env body)
154 | Case (term, indty, outty_opt, patterns) ->
155 Case (aux env term, indty, aux_opt env outty_opt,
156 List.map (aux_branch env) patterns)
157 | LetIn (var, t1, t2) ->
158 LetIn (aux_capture_var env var, aux env t1, aux env t2)
159 | LetRec (kind, definitions, body) ->
160 LetRec (kind, List.map (aux_definition env) definitions, aux env body)
161 | Uri (name, None) -> Uri (name, None)
162 | Uri (name, Some substs) -> Uri (name, Some (aux_substs env substs))
163 | Ident (name, Some substs) -> Ident (name, Some (aux_substs env substs))
164 | Meta (index, substs) -> Meta (index, aux_meta_substs env substs)
173 | Magic magic -> aux_magic env magic
174 | Variable var -> aux_variable env var
177 and aux_opt env = function
178 | Some term -> Some (aux env term)
180 and aux_capture_var env (name, ty_opt) = (aux env name, aux_opt env ty_opt)
181 and aux_branch env (pattern, term) =
182 (aux_pattern env pattern, aux env term)
183 and aux_pattern env (head, vars) =
184 (head, List.map (aux_capture_var env) vars)
185 and aux_definition env (var, term, i) =
186 (aux_capture_var env var, aux env term, i)
187 and aux_substs env substs =
188 List.map (fun (name, term) -> (name, aux env term)) substs
189 and aux_meta_substs env meta_substs = List.map (aux_opt env) meta_substs
190 and aux_variable env = function
191 | NumVar name -> Num (lookup_num env name, 0)
192 | IdentVar name -> Ident (lookup_string env name, None)
193 | TermVar name -> lookup_term env name
194 | FreshVar name -> Ident (lookup_fresh_name name, None)
195 | Ascription (term, name) -> assert false
196 and aux_magic env = function
197 | Default (some_pattern, none_pattern) ->
198 (match meta_names_of some_pattern with
199 | [] -> assert false (* some pattern must contain at least 1 name *)
200 | (name :: _) as names ->
201 (match lookup_value env name with
202 | OptValue (Some _) ->
203 (* assumption: if "name" above is bound to Some _, then all
204 * names returned by "meta_names_of" are bound to Some _ as well
206 aux (unopt_names names env) some_pattern
207 | OptValue None -> aux env none_pattern
208 | _ -> assert false))
209 | Fold (`Left, base_pattern, names, rec_pattern) ->
210 let acc_name = List.hd names in (* names can't be empty, cfr. parser *)
212 List.filter ((<>) acc_name) (meta_names_of rec_pattern)
214 (match meta_names with
215 | [] -> assert false (* as above *)
216 | (name :: _) as names ->
217 let rec instantiate_fold_left acc env' =
218 prerr_endline "instantiate_fold_left";
219 match lookup_value env' name with
220 | ListValue (_ :: _) ->
221 instantiate_fold_left
222 (let acc_binding = acc_name, (TermType, TermValue acc) in
223 aux (acc_binding :: head_names names env') rec_pattern)
224 (tail_names names env')
225 | ListValue [] -> acc
228 instantiate_fold_left (aux env base_pattern) env)
229 | Fold (`Right, base_pattern, names, rec_pattern) ->
230 let acc_name = List.hd names in (* names can't be empty, cfr. parser *)
232 List.filter ((<>) acc_name) (meta_names_of rec_pattern)
234 (match meta_names with
235 | [] -> assert false (* as above *)
236 | (name :: _) as names ->
237 let rec instantiate_fold_right env' =
238 prerr_endline "instantiate_fold_right";
239 match lookup_value env' name with
240 | ListValue (_ :: _) ->
241 let acc = instantiate_fold_right (tail_names names env') in
242 let acc_binding = acc_name, (TermType, TermValue acc) in
243 aux (acc_binding :: head_names names env') rec_pattern
244 | ListValue [] -> aux env base_pattern
247 instantiate_fold_right env)