+(* 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/
+ *)
+
+type coerc_carr = Uri of UriManager.uri | Sort of Cic.sort | Term of Cic.term
+exception EqCarrNotImplemented of string Lazy.t
+exception EqCarrOnNonMetaClosed
+
let db = ref []
+let use_coercions = ref true
+
+let coerc_carr_of_term t =
+ try
+ Uri (CicUtil.uri_of_term t)
+ with Invalid_argument _ ->
+ match t with
+ | Cic.Sort s -> Sort s
+ | t -> Term t
+;;
+
+let eq_carr src tgt =
+ match src, tgt with
+ | Uri src, Uri tgt -> UriManager.eq src tgt
+ | Sort (Cic.Type _), Sort (Cic.Type _) -> true
+ | Sort src, Sort tgt when src = tgt -> true
+ | Term t1, Term t2 when
+ CicUtil.is_meta_closed t1 && CicUtil.is_meta_closed t2 ->
+ raise
+ (EqCarrNotImplemented
+ (lazy ("Unsupported carr for coercions: " ^
+ CicPp.ppterm t1 ^ " or " ^ CicPp.ppterm t2)))
+ | _ -> raise EqCarrOnNonMetaClosed
+
+let name_of_carr = function
+ | Uri u -> UriManager.name_of_uri u
+ | Sort s -> CicPp.ppsort s
+ | Term _ -> assert false
+
let to_list () =
!db
db := List.filter (fun u -> not(p u)) !db
let find_coercion f =
- List.map (fun (_,_,x) -> x) (List.filter (fun (s,t,_) -> f (s,t)) !db)
+ if !use_coercions then
+ List.map (fun (_,_,x) -> x) (List.filter (fun (s,t,_) -> f (s,t)) !db)
+ else []