Contributions are always welcome :)

I think it could be implemented for more than just Map, though. You should be able to implement it for any Traversable/Applicative... could you do that? I imagine you're thinking of something like

def filterM[M[_]: Monad, K, V](fa: K ==>> V)(f: (K, V) => M[Boolean]): M[K ==>> V]

?

kida, yes

filterM[F[_]](p: B => F[Boolean])(implicit F: Applicative[F], o: Order[A]): F[A ==>> B]

to be more precise
(you don't even need a Monad, mere Applicative Functor is enough)

@sideeffffect either way, please open a pull request if you have an implementation; that's the easiest way to get a new feature 😉

sorry, for complicated corporate reasons, it will take weeks before I will open a PR for this -- I just wanted to test the waters that it's even conceivable that something like that function would be accepted
let's hope it won't take long and nobody will be faster than me with ==>>.filterM