diff options
| -rw-r--r-- | compiler/basicTypes/VarEnv.lhs | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/compiler/basicTypes/VarEnv.lhs b/compiler/basicTypes/VarEnv.lhs index 7e28d1a4f1..2699748d65 100644 --- a/compiler/basicTypes/VarEnv.lhs +++ b/compiler/basicTypes/VarEnv.lhs @@ -19,7 +19,7 @@ module VarEnv ( modifyVarEnv, modifyVarEnv_Directly, isEmptyVarEnv, foldVarEnv, elemVarEnvByKey, lookupVarEnv_Directly, - filterVarEnv_Directly, + filterVarEnv_Directly, restrictVarEnv, -- * The InScopeSet type InScopeSet, @@ -321,6 +321,7 @@ extendVarEnvList :: VarEnv a -> [(Var, a)] -> VarEnv a lookupVarEnv_Directly :: VarEnv a -> Unique -> Maybe a filterVarEnv_Directly :: (Unique -> a -> Bool) -> VarEnv a -> VarEnv a +restrictVarEnv :: VarEnv a -> VarSet -> VarEnv a delVarEnvList :: VarEnv a -> [Var] -> VarEnv a delVarEnv :: VarEnv a -> Var -> VarEnv a plusVarEnv_C :: (a -> a -> a) -> VarEnv a -> VarEnv a -> VarEnv a @@ -361,6 +362,10 @@ foldVarEnv = foldUFM lookupVarEnv_Directly = lookupUFM_Directly filterVarEnv_Directly = filterUFM_Directly +restrictVarEnv env vs = filterVarEnv_Directly keep env + where + keep u _ = u `elemVarSetByKey` vs + zipVarEnv tyvars tys = mkVarEnv (zipEqual "zipVarEnv" tyvars tys) lookupVarEnv_NF env id = case lookupVarEnv env id of Just xx -> xx |