Various fixes on typeclasses:

- Better interface in constrintern w.r.t. evars used during typechecking
- Add "unsatisfiable_constraints" exception which gives back the raw
evar_map that was not satisfied during typeclass search (presentation
could be improved).
- Correctly infer the minimal sort for typeclasses declared as
definitions (everything was in type before).
- Really handle priorities in typeclass eauto: goals produced with higher
priority (lowest number) instances are tried before other of lower
priority goals, regardless of the number of subgoals.
- Change inverse to a notation for flip, now that universe polymorphic
definitions are handled correctly. 
- Add EquivalenceDec class similar to SetoidDec, declaring decision
procedures for equivalences.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10724 85f007b7-540e-0410-9357-904b9bb8a0f7

3 files changed, 9 insertions, 1 deletions

diff --git a/pretyping/pretyping.ml b/pretyping/pretyping.ml
index 980a5075f..f9fcdb7b6 100644
--- a/pretyping/pretyping.ml
+++ b/pretyping/pretyping.ml
@@ -700,7 +700,9 @@ module Pretyping_F (Coercion : Coercion.S) = struct
     let evdref = ref (Evd.create_evar_defs sigma) in
     let c = pretype_gen evdref env lvar kind c in
     let evd,_ = consider_remaining_unif_problems env !evdref in
-      if fail_evar then check_evars env Evd.empty evd c;
+      if fail_evar then 
+	(let evd = Typeclasses.resolve_typeclasses ~onlyargs:false ~all:false env (evars_of evd) evd in
+	   check_evars env Evd.empty evd c);
       evd, c
 
   (** Entry points of the high-level type synthesis algorithm *)
diff --git a/pretyping/typeclasses_errors.ml b/pretyping/typeclasses_errors.ml
index 1648f667a..4db826108 100644
--- a/pretyping/typeclasses_errors.ml
+++ b/pretyping/typeclasses_errors.ml
@@ -28,6 +28,7 @@ type typeclass_error =
     | NotAClass of constr
     | UnboundMethod of global_reference * identifier located (* Class name, method *)
     | NoInstance of identifier located * constr list
+    | UnsatisfiableConstraints of evar_map
     | MismatchedContextInstance of contexts * constr_expr list * named_context (* found, expected *)
 
 exception TypeClassError of env * typeclass_error
@@ -40,4 +41,6 @@ let unbound_method env cid id = typeclass_error env (UnboundMethod (cid, id))
 
 let no_instance env id args = typeclass_error env (NoInstance (id, args))
 
+let unsatisfiable_constraints env evm = typeclass_error env (UnsatisfiableConstraints evm)
+
 let mismatched_ctx_inst env c n m = typeclass_error env (MismatchedContextInstance (c, n, m))
diff --git a/pretyping/typeclasses_errors.mli b/pretyping/typeclasses_errors.mli
index 82e37f41d..a697087d2 100644
--- a/pretyping/typeclasses_errors.mli
+++ b/pretyping/typeclasses_errors.mli
@@ -28,6 +28,7 @@ type typeclass_error =
     | NotAClass of constr
     | UnboundMethod of global_reference * identifier located (* Class name, method *)
     | NoInstance of identifier located * constr list
+    | UnsatisfiableConstraints of evar_map
     | MismatchedContextInstance of contexts * constr_expr list * named_context (* found, expected *)
 
 exception TypeClassError of env * typeclass_error
@@ -38,4 +39,6 @@ val unbound_method : env -> global_reference -> identifier located -> 'a
 
 val no_instance : env -> identifier located -> constr list -> 'a
 
+val unsatisfiable_constraints : env -> evar_map -> 'a
+
 val mismatched_ctx_inst : env -> contexts -> constr_expr list -> named_context -> 'a