import Prelude hiding (lookup,map,filter,foldr,foldl,null)
import Data.Bits
import Data.Int
-import Data.Monoid
import qualified Data.IntSet as IntSet
import Data.Typeable
-- | /O(log n)/. Performs a 'split' but also returns whether the pivot
-- key was found in the original map.
-splitLookup :: Key -> IntMap a -> (Maybe a,IntMap a,IntMap a)
+splitLookup :: Key -> IntMap a -> (IntMap a,Maybe a,IntMap a)
splitLookup k t
= case t of
Bin p m l r
- | zero k m -> let (found,lt,gt) = splitLookup k l in (found,lt,union gt r)
- | otherwise -> let (found,lt,gt) = splitLookup k r in (found,union l lt,gt)
+ | zero k m -> let (lt,found,gt) = splitLookup k l in (lt,found,union gt r)
+ | otherwise -> let (lt,found,gt) = splitLookup k r in (union l lt,found,gt)
Tip ky y
- | k>ky -> (Nothing,t,Nil)
- | k<ky -> (Nothing,Nil,t)
- | otherwise -> (Just y,Nil,Nil)
- Nil -> (Nothing,Nil,Nil)
+ | k>ky -> (t,Nothing,Nil)
+ | k<ky -> (Nil,Nothing,t)
+ | otherwise -> (Nil,Just y,Nil)
+ Nil -> (Nil,Nothing,Nil)
{--------------------------------------------------------------------
Fold
fmap = map
{--------------------------------------------------------------------
- Monoid
---------------------------------------------------------------------}
-
-instance Ord a => Monoid (IntMap a) where
- mempty = empty
- mappend = union
- mconcat = unions
-
-{--------------------------------------------------------------------
Show
--------------------------------------------------------------------}