Check category of type instances and some newtype family fixes

[ghc-hetmet.git] / compiler / types / Type.lhs

diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index a7aeeec..b7f1a00 100644 (file)
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -117,7 +117,8 @@ import PrelNames( openTypeKindTyConKey, unliftedTypeKindTyConKey,
                   ubxTupleKindTyConKey, argTypeKindTyConKey )
 import TyCon   ( TyCon, isRecursiveTyCon, isPrimTyCon,
                  isUnboxedTupleTyCon, isUnLiftedTyCon,
-                 isFunTyCon, isNewTyCon, newTyConRep, newTyConRhs,
+                 isFunTyCon, isNewTyCon, isOpenTyCon, newTyConRep,
+                 newTyConRhs, 
                  isAlgTyCon, tyConArity, isSuperKindTyCon,
                  tcExpandTyCon_maybe, coreExpandTyCon_maybe,
                  tyConKind, PrimRep(..), tyConPrimRep, tyConUnique,
@@ -448,7 +449,7 @@ repType looks through
        (b) synonyms
        (c) predicates
        (d) usage annotations
-       (e) all newtypes, including recursive ones
+       (e) all newtypes, including recursive ones, but not newtype families
 It's useful in the back end.
 
 \begin{code}
@@ -457,7 +458,8 @@ repType :: Type -> Type
 repType ty | Just ty' <- coreView ty = repType ty'
 repType (ForAllTy _ ty)  = repType ty
 repType (TyConApp tc tys)
-  | isNewTyCon tc       = -- Recursive newtypes are opaque to coreView
+  | isNewTyCon tc &&
+    not (isOpenTyCon tc) = -- Recursive newtypes are opaque to coreView
                           -- but we must expand them here.  Sure to
                           -- be saturated because repType is only applied
                           -- to types of kind *