category-extras-0.53.4: Various modules and constructs inspired by category theory

Portabilityportable
Stabilityexperimental
MaintainerEdward Kmett <ekmett@gmail.com>

Control.Functor.Contra

Description

 

Documentation

class ContraFunctor f whereSource

Methods

contramap :: (a -> b) -> f b -> f aSource

Instances

newtype ContraF a b Source

Constructors

ContraF 

Fields

runContraF :: b -> a
 

Instances