| Portability | GADTs, TFs, MPTCs |
|---|---|
| Stability | provisional |
| Maintainer | Edward Kmett <ekmett@gmail.com> |
| Safe Haskell | Trustworthy |
Data.Functor.Contravariant.Yoneda
Description
- newtype Yoneda f a = Yoneda {
- runYoneda :: forall r. (r -> a) -> f r
- liftYoneda :: Contravariant f => f a -> Yoneda f a
- lowerYoneda :: Yoneda f a -> f a
Documentation
Yoneda embedding for a presheaf
Instances
| Contravariant (Yoneda f) | |
| Representable f => Representable (Yoneda f) | |
| Adjunction f g => Adjunction (Yoneda f) (Yoneda g) |
liftYoneda :: Contravariant f => f a -> Yoneda f aSource
liftYoneda.lowerYoneda≡idlowerYoneda.liftYoneda≡id
lowerYoneda :: Yoneda f a -> f aSource