`Selective` exercise: `select` of `handle`

select.hs

import Data.Either  (either)
import Data.Functor ((<$>))

class Applicative f => Selective f where
    handle :: f (Either a b) -> f (a -> b) -> f b

select :: Selective f =>
    f (Either a b) -> f (a -> c) -> f (b -> c) -> f c
select e fa fb = handle (Left <$> e) (either <$> fa <*> fb)

main = undefined