) where
import Prelude
+import Data.Map ( Map )
+import qualified Data.Map as Map hiding ( Map )
+import Data.IntMap ( IntMap )
+import qualified Data.IntMap as IntMap hiding ( IntMap )
+import Data.Set ( Set )
+import qualified Data.Set as Set hiding ( Set )
+import Data.IntSet ( IntSet )
+import qualified Data.IntSet as IntSet hiding ( IntSet )
-- ---------------------------------------------------------------------------
-- | The monoid class.
LT `mappend` _ = LT
EQ `mappend` y = y
GT `mappend` _ = GT
+
+instance (Ord k) => Monoid (Map k v) where
+ mempty = Map.empty
+ mappend = Map.union
+ mconcat = Map.unions
+
+instance Ord a => Monoid (IntMap a) where
+ mempty = IntMap.empty
+ mappend = IntMap.union
+ mconcat = IntMap.unions
+
+instance Ord a => Monoid (Set a) where
+ mempty = Set.empty
+ mappend = Set.union
+ mconcat = Set.unions
+
+instance Monoid IntSet where
+ mempty = IntSet.empty
+ mappend = IntSet.union
+ mconcat = IntSet.unions