[Haskell-cafe] mapM for vectors

Hello I found that there is no monadic map for vector. It's possible to define to define such map using conversion to list, but I suppose it's not efficient. I didn't make any measurements.

mapM' :: Monad m => (a -> m b) -> V.Vector a -> m (V.Vector b) mapM' f = return . V.fromList <=< mapM f . V.toList

Any suggestions about implementation of such function? Specifically I want to use Random monad. -- Khudyakov Alexey