Added a new function, filterMapByKey, to the Utils module

common/Utils.hs

@@ -346,6 +346,9 @@ mapMapWithKeyM f m = liftM Map.fromAscList $ mapM f' $ Map.toAscList m
     f' (x,y) = do y' <- f x y
                   return (x, y')
 
+filterMapByKey :: Ord k => (k -> Bool) -> Map.Map k v -> Map.Map k v
+filterMapByKey f = Map.filterWithKey (\k _ -> f k)
+
 -- | Transforms an Either into a Maybe.  If it's a Left value, it is transformed
 -- into Nothing.  If it is a Right value, it is transformed into Just.
 eitherToMaybe :: Either a b -> Maybe b