mkDictTy :: Class -> [Type] -> Type
mkDictTy clas tys = mkPredTy (ClassP clas tys)
-isDictTy :: Type -> Bool
-isDictTy ty | Just ty' <- tcView ty = isDictTy ty'
-isDictTy (PredTy p) = isClassPred p
-isDictTy _ = False
-
isDictLikeTy :: Type -> Bool
-- Note [Dictionary-like types]
isDictLikeTy ty | Just ty' <- tcView ty = isDictTy ty'