-
-emptyOccEnv = emptyUFM
-unitOccEnv = unitUFM
-extendOccEnv = addToUFM
-extendOccEnvList = addListToUFM
-lookupOccEnv = lookupUFM
-mkOccEnv = listToUFM
-elemOccEnv = elemUFM
-foldOccEnv = foldUFM
-occEnvElts = eltsUFM
-plusOccEnv = plusUFM
-plusOccEnv_C = plusUFM_C
-extendOccEnv_C = addToUFM_C
-mapOccEnv = mapUFM
-
-type OccSet = UniqFM OccName
+delFromOccEnv :: OccEnv a -> OccName -> OccEnv a
+delListFromOccEnv :: OccEnv a -> [OccName] -> OccEnv a
+filterOccEnv :: (elt -> Bool) -> OccEnv elt -> OccEnv elt
+
+emptyOccEnv = A emptyUFM
+unitOccEnv x y = A $ unitUFM x y
+extendOccEnv (A x) y z = A $ addToUFM x y z
+extendOccEnvList (A x) l = A $ addListToUFM x l
+lookupOccEnv (A x) y = lookupUFM x y
+mkOccEnv l = A $ listToUFM l
+elemOccEnv x (A y) = elemUFM x y
+foldOccEnv a b (A c) = foldUFM a b c
+occEnvElts (A x) = eltsUFM x
+plusOccEnv (A x) (A y) = A $ plusUFM x y
+plusOccEnv_C f (A x) (A y) = A $ plusUFM_C f x y
+extendOccEnv_C f (A x) y z = A $ addToUFM_C f x y z
+mapOccEnv f (A x) = A $ mapUFM f x
+mkOccEnv_C comb l = A $ addListToUFM_C comb emptyUFM l
+delFromOccEnv (A x) y = A $ delFromUFM x y
+delListFromOccEnv (A x) y = A $ delListFromUFM x y
+filterOccEnv x (A y) = A $ filterUFM x y
+
+instance Outputable a => Outputable (OccEnv a) where
+ ppr (A x) = ppr x
+
+type OccSet = UniqSet OccName