Data.Functor.Contravariant.Rep

classclass Contravariant f => Representable (f :: Type -> Type) where

A Contravariant functor f is Representable if tabulate and index witness an isomorphism to (_ -> Rep f).

tabulate . index ≡ id
index . tabulate ≡ id

tabulate :: (a -> Rep f) -> f a

contramap f (tabulate g) = tabulate (g . f)

contramapWithRep :: (b -> Either a (Rep f)) -> f a -> f b

contramapWithRep f p ≡ tabulate $ either (index p) id . f

Instances6Representable

Representable PredicateDefined in adjunctions-4.4.3 · Data.Functor.Contravariant.Rep
Representable ProxyDefined in adjunctions-4.4.3 · Data.Functor.Contravariant.Rep
Representable U1Defined in adjunctions-4.4.3 · Data.Functor.Contravariant.Rep
Representable (Op r)Defined in adjunctions-4.4.3 · Data.Functor.Contravariant.Rep
(Representable f, Representable g) => Representable (Product f g)Defined in adjunctions-4.4.3 · Data.Functor.Contravariant.Rep
(Representable f, Representable g) => Representable (f :*: g)Defined in adjunctions-4.4.3 · Data.Functor.Contravariant.Rep

Representable Contravariant Functors