X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_unification%2FcoercDb.ml;h=437ad65ae202bcddab717c3fa5e5d327f63d6dfc;hb=97c2d258a5c524eb5c4b85208899d80751a2c82f;hp=859445f44110fa2879cae2393bb3574216fa6bca;hpb=edad2cd49734428c522afaa01201bb0a49346d42;p=helm.git

diff --git a/helm/ocaml/cic_unification/coercDb.ml b/helm/ocaml/cic_unification/coercDb.ml
index 859445f44..437ad65ae 100644
--- a/helm/ocaml/cic_unification/coercDb.ml
+++ b/helm/ocaml/cic_unification/coercDb.ml
@@ -23,9 +23,42 @@
  * 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