categories-0.59: categories from category-extras

Portabilityportable
Stabilityexperimental
MaintainerEdward Kmett <ekmett@gmail.com>
Safe HaskellSafe-Infered

Control.Category.Discrete

Description

 

Synopsis

Documentation

data Discrete a b whereSource

Category of discrete objects. The only arrows are identity arrows.

Constructors

Refl :: Discrete a a 

Instances

liftDiscrete :: Discrete a b -> Discrete (f a) (f b)Source

Discrete a b acts as a proof that a = b, lift that proof into something of kind * -> *

cast :: Category k => Discrete a b -> k a bSource

Lower the proof that a ~ b to an arbitrary category.

inverse :: Discrete a b -> Discrete b aSource