X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_unification%2FcoercDb.ml;h=437ad65ae202bcddab717c3fa5e5d327f63d6dfc;hb=4167cea65ca58897d1a3dbb81ff95de5074700cc;hp=6a514b814c95647e1a9b77fc6a06aae868f0b94c;hpb=6707bdbd677ee7709bebec14880e1673b4048c6d;p=helm.git

diff --git a/helm/ocaml/cic_unification/coercDb.ml b/helm/ocaml/cic_unification/coercDb.ml
index 6a514b814..437ad65ae 100644
--- a/helm/ocaml/cic_unification/coercDb.ml
+++ b/helm/ocaml/cic_unification/coercDb.ml
@@ -1,4 +1,63 @@
+(* 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 ->
+    if CicUtil.is_meta_closed t1 && CicUtil.is_meta_closed t2 then
+      raise 
+        (EqCarrNotImplemented 
+          (lazy ("Unsupported carr for coercions: " ^ 
+            CicPp.ppterm t1 ^ " or " ^ CicPp.ppterm t2)))
+    else raise EqCarrOnNonMetaClosed
+  | _, _ -> false
+
+let name_of_carr = function
+  | Uri u -> UriManager.name_of_uri u
+  | Sort s -> CicPp.ppsort s
+  | Term t -> CicPp.ppterm t
+  
 
 let to_list () =
   !db
@@ -10,5 +69,7 @@ let remove_coercion p =
   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 []