Do another pass on the typeclasses code. Correct globalization of class

names, gives the ability to specify qualified classes in instance
declarations. Use that in the class_tactics code. 
Refine the implementation of classes. For singleton classes the
implementation of the class becomes a regular definition (into Type or
Prop). The single method becomes a 'trivial' projection that allows to
launch typeclass resolution. Each instance is just a definition as
usual. Examples in theories/Classes/RelationClasses. This permits to
define [Class reflexive A (R : relation A) := refl : forall x, R x
x.]. The definition of [reflexive] that is generated is the same as the
original one. We just need a way to declare arbitrary lemmas as
instances of a particular class to retrofit existing reflexivity lemmas
as typeclass instances of the [reflexive] class. 
Also debug rewriting under binders in setoid_rewrite to allow rewriting
with lemmas which capture the bound variables when applied (works only
with setoid_rewrite, as rewrite first matches the lemma with the entire,
closed term). One can rewrite with [H : forall x, R (f x) (g x)] in the goal
[exists x, P (f x)].


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10697 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 4 insertions, 3 deletions

diff --git a/pretyping/typeclasses_errors.ml b/pretyping/typeclasses_errors.ml
index 980f327cb..1648f667a 100644
--- a/pretyping/typeclasses_errors.ml
+++ b/pretyping/typeclasses_errors.ml
@@ -19,13 +19,14 @@ open Nametab
 open Mod_subst
 open Topconstr
 open Util
+open Libnames
 (*i*)
 
 type contexts = Parameters | Properties
 
 type typeclass_error = 
-    | UnboundClass of identifier located
-    | UnboundMethod of identifier * identifier located (* Class name, method *)
+    | NotAClass of constr
+    | UnboundMethod of global_reference * identifier located (* Class name, method *)
     | NoInstance of identifier located * constr list
     | MismatchedContextInstance of contexts * constr_expr list * named_context (* found, expected *)
 
@@ -33,7 +34,7 @@ exception TypeClassError of env * typeclass_error
 
 let typeclass_error env err = raise (TypeClassError (env, err))
 
-let unbound_class env id = typeclass_error env (UnboundClass id)
+let not_a_class env c = typeclass_error env (NotAClass c)
 
 let unbound_method env cid id = typeclass_error env (UnboundMethod (cid, id))