Proposal: Add filterM or filterA to Data.Sequence

This can be given exactly the same implementation as the one for lists: filterM :: (Applicative f) => (a -> f Bool) -> Seq a -> f (Seq a) filterM p = foldr go (pure empty) where go x r = f <$> p x <*> r where f flg ys = if flg then x <| ys else ys Bikeshed all you like over the name.