--- /dev/null
+(* Copyright (C) 2000, 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://cs.unibo.it/helm/.
+ *)
+
+(* $Id$ *)
+
+open Printf;;
+
+type coercion_search_result =
+ | SomeCoercion of Cic.term
+ | NoCoercion
+ | NotMetaClosed
+ | NotHandled of string Lazy.t
+
+let debug = false
+let debug_print s = if debug then prerr_endline (Lazy.force s) else ()
+
+(* searches a coercion fron src to tgt in the !coercions list *)
+let look_for_coercion src tgt =
+ try
+ let l =
+ CoercDb.find_coercion
+ (fun (s,t) -> CoercDb.eq_carr s src && CoercDb.eq_carr t tgt)
+ in
+ match l with
+ | [] ->
+ debug_print
+ (lazy
+ (sprintf ":-( coercion non trovata da %s a %s"
+ (CoercDb.name_of_carr src)
+ (CoercDb.name_of_carr tgt)));
+ NoCoercion
+ | [u] ->
+ debug_print (lazy (
+ sprintf ":-) TROVATA 1 coercion da %s a %s: %s"
+ (CoercDb.name_of_carr src)
+ (CoercDb.name_of_carr tgt)
+ (UriManager.name_of_uri u)));
+ SomeCoercion (CicUtil.term_of_uri u)
+ | u::_ ->
+ debug_print (lazy (
+ sprintf ":-/ TROVATE %d coercion(s) da %s a %s, prendo la prima: %s"
+ (List.length l)
+ (CoercDb.name_of_carr src)
+ (CoercDb.name_of_carr tgt)
+ (UriManager.name_of_uri u)));
+ SomeCoercion (CicUtil.term_of_uri u)
+ with
+ | CoercDb.EqCarrNotImplemented s -> NotHandled s
+ | CoercDb.EqCarrOnNonMetaClosed -> NotMetaClosed
+;;
+
+let look_for_coercion src tgt =
+ let src_uri = CoercDb.coerc_carr_of_term src in
+ let tgt_uri = CoercDb.coerc_carr_of_term tgt in
+ look_for_coercion src_uri tgt_uri
+
+let is_a_coercion t =
+ try
+ let uri = CicUtil.uri_of_term t in
+ CoercDb.is_a_coercion uri
+ with Invalid_argument _ -> false
+
+let source_of t =
+ try
+ let uri = CicUtil.uri_of_term t in
+ CoercDb.term_of_carr (fst (CoercDb.get_carr uri))
+ with Invalid_argument _ -> assert false (* t must be a coercion *)
+
+let target_of t =
+ try
+ let uri = CicUtil.uri_of_term t in
+ CoercDb.term_of_carr (snd (CoercDb.get_carr uri))
+ with Invalid_argument _ -> assert false (* t must be a coercion *)
+
+(* EOF *)