Haskell Language Learning note (distributive)

Distributive

class Functor g => Distributive g where  distribute  :: Functor f => f (g a) -> g (f a)  distribute  = collect id  collect     :: Functor f => (a -> g b) -> f a -> g (f b)  collect f   = distribute . fmap f  distributeM :: Monad m => m (g a) -> g (m a)  distributeM = fmap unwrapMonad . distribute . WrapMonad  collectM    :: Monad m => (a -> g b) -> m a -> g (m b)  collectM f  = distributeM . liftM fcotraverse :: (Distributive g, Functor f) => (f a -> b) -> f (g a) -> g bcotraverse f = fmap f . distributecomapM :: (Distributive g, Monad m) => (m a -> b) -> m (g a) -> g bcomapM f = fmap f . distributeM

((e)) is a distributive

instance Distributive ((->)e) where  distribute a e = fmap ($e) a  collect f q e = fmap (flip f e) q

Prelude Data.Distributive> distribute [(+1),(+2)] 1[2,3]Prelude Data.Distributive> collect (^) [1,2] 3[1,8]

Haskell Language Learning note (distributive)