Re: [Haskell-cafe] mapFst and mapSnd

On Thu, May 30, 2013 at 10:56 PM, Tony Morris wrote:

class BinaryFunctor f where bimap :: (a -> c) -> (b -> d) -> f a b -> f c d

mapFst = (`bimap id`) mapSnd = bimap id

There's a bifunctors package with: class Bifunctor f where bimap :: ... first :: a -> b -> f a c -> f b c second :: b -> c -> f a b -> f a c