Faster filterF, filterNotByte

[ghc-base.git] / Data / Set.hs

diff --git a/Data/Set.hs b/Data/Set.hs
index 13dff75..36c7ecd 100644 (file)
--- a/Data/Set.hs
+++ b/Data/Set.hs
@@ -43,6 +43,7 @@ module Data.Set  (
             , null
             , size
             , member
+            , notMember
             , isSubsetOf
             , isProperSubsetOf
             
@@ -203,6 +204,10 @@ member x t
                GT -> member x r
                EQ -> True       
 
+-- | /O(log n)/. Is the element not in the set?
+notMember :: Ord a => a -> Set a -> Bool
+notMember x t = not $ member x t
+
 {--------------------------------------------------------------------
   Construction
 --------------------------------------------------------------------}