+lookupTyCon tc
+ | isUnLiftedTyCon tc || isTupleTyCon tc = return (Just tc)
+
+ | otherwise = readGEnv $ \env -> lookupNameEnv (global_tycons env) (tyConName tc)
+
+defTyCon :: TyCon -> TyCon -> VM ()
+defTyCon tc tc' = updGEnv $ \env ->
+ env { global_tycons = extendNameEnv (global_tycons env) (tyConName tc) tc' }
+
+lookupDataCon :: DataCon -> VM (Maybe DataCon)
+lookupDataCon dc = readGEnv $ \env -> lookupNameEnv (global_datacons env) (dataConName dc)
+
+defDataCon :: DataCon -> DataCon -> VM ()
+defDataCon dc dc' = updGEnv $ \env ->
+ env { global_datacons = extendNameEnv (global_datacons env) (dataConName dc) dc' }