Data.Comp.ExpFunctor

Exponential functors, see http://comonad.com/reader/2008/rotten-bananas/.

Documentation

class ExpFunctor f where

Exponential functors are functors that may be both covariant (as ordinary functors) and contravariant.

Methods

xmap :: (a -> b) -> (b -> a) -> f a -> f b

Instances

ExpFunctor f => ExpFunctor (:&: f a)

(ExpFunctor f, ExpFunctor g) => ExpFunctor (:+: f g)