Data.Functor.Contravariant.Yoneda.Reduction

Yoneda Reduction of presheafs

http://ncatlab.org/nlab/show/Yoneda+reduction

Documentation

data Yoneda f a where

A Contravariant functor (aka presheaf) suitable for Yoneda reduction.

Constructors

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

Instances

Contravariant (Yoneda f)

Valued f => Valued (Yoneda f)

Coindexed f => Coindexed (Yoneda f)

Representable f => Representable (Yoneda f)

Adjunction f g => Adjunction (Yoneda f) (Yoneda g)

liftYoneda :: f a -> Yoneda f a

Yoneda expansion of a presheaf

lowerYoneda :: Contravariant f => Yoneda f a -> f a

Yoneda reduction on a presheaf