added use_coercions flag (imperative :-(, non re-entrant :-(((( )

[helm.git] / helm / ocaml / cic_unification / coercDb.ml

diff --git a/helm/ocaml/cic_unification/coercDb.ml b/helm/ocaml/cic_unification/coercDb.ml
index 6a514b814c95647e1a9b77fc6a06aae868f0b94c..859445f44110fa2879cae2393bb3574216fa6bca 100644 (file)
--- a/helm/ocaml/cic_unification/coercDb.ml
+++ b/helm/ocaml/cic_unification/coercDb.ml
@@ -1,4 +1,30 @@
+(* 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/
+ *)
+
 let db = ref []
+let use_coercions = ref true
 
 let to_list () =
   !db
@@ -10,5 +36,7 @@ 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 []