[project @ 2004-01-23 13:35:16 by ross]

add a Functor instance for FiniteMap

diff --git a/Data/FiniteMap.hs b/Data/FiniteMap.hs
index 44d2437..e63d92b 100644 (file)
--- a/Data/FiniteMap.hs
+++ b/Data/FiniteMap.hs
@@ -280,6 +280,9 @@ bagToFM = foldBag plusFM (\ (k,v) -> unitFM k v) emptyFM
 instance (Show k, Show e) => Show (FiniteMap k e) where
   showsPrec p m = showsPrec p (fmToList m)
 
+instance Functor (FiniteMap k) where
+  fmap f = mapFM (const f)
+
 -- ---------------------------------------------------------------------------
 -- Adding to and deleting from @FiniteMaps@