we must forget abbrevs when switching to the old method of unification. removed unify_old: unify now decides for itself whether to use the old or the new method

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/gadts@10803 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

typing/ctype.ml

@@ -2015,7 +2015,9 @@ and unify3 mode env t1 t1' t2 t2' =
   in
   let switch_to_old_link () = 
     match mode with
-    | Pattern | Expression -> old_link ();
+    | Pattern | Expression -> 
+	cleanup_abbrev ();
+	old_link ();
     | Old -> () (* old_link was already called *)
   in
   match d1, d2 with
@@ -2391,13 +2393,12 @@ let unify_pairs env ty1 ty2 pairs =
   univar_pairs := pairs;
   unify Expression env ty1 ty2
 
-let unify_old env ty1 ty2 =
-  univar_pairs := [];
-  unify Old (ref env) ty1 ty2
-
 let unify env ty1 ty2 =
   univar_pairs := [];
-  unify Expression (ref env) ty1 ty2
+  if Env.has_local_constraints env then 
+    unify Expression (ref env) ty1 ty2
+  else
+    unify Old (ref env) ty1 ty2
 
 let unify_gadt env ty1 ty2 = 
   univar_pairs := [];

typing/ctype.mli

@@ -141,8 +141,6 @@ val full_expand: Env.t -> type_expr -> type_expr
 
 val enforce_constraints: Env.t -> type_expr -> unit
 
-val unify_old: Env.t -> type_expr -> type_expr -> unit
-        (* Unify the two types given. Raise [Unify] if not possible. Use the old method of unification *)
 val unify: Env.t -> type_expr -> type_expr -> unit
         (* Unify the two types given. Raise [Unify] if not possible. *)
 val unify_gadt: int -> Env.t ref -> type_expr -> type_expr -> unit

typing/typecore.ml

@@ -165,10 +165,7 @@ let unify_exp_types loc env ty expected_ty =
   (* Format.eprintf "@[%a@ %a@]@." Printtyp.raw_type_expr exp.exp_type
     Printtyp.raw_type_expr expected_ty; *)
   try
-    if Env.has_local_constraints env then 
-      unify env ty expected_ty
-    else
-      unify_old env ty expected_ty
+    unify env ty expected_ty
   with
     Unify trace ->
       raise(Error(loc, Expr_type_clash(trace)))