kan-extensions-4.2.2: Kan extensions, Kan lifts, various forms of the Yoneda lemma, and (co)density (co)monads

Copyright(C) 2013 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
PortabilityGADTs, TFs, MPTCs
Safe HaskellTrustworthy
LanguageHaskell98

Data.Functor.Contravariant.Yoneda

Description

 

Synopsis

Documentation

newtype Yoneda f a Source

Yoneda embedding for a presheaf

Constructors

Yoneda 

Fields

runYoneda :: forall r. (r -> a) -> f r
 

Instances

Contravariant (Yoneda f) 
Representable f => Representable (Yoneda f) 
Adjunction f g => Adjunction (Yoneda f) (Yoneda g) 
type Rep (Yoneda f) = Rep f 

liftYoneda :: Contravariant f => f a -> Yoneda f a Source

lowerYoneda :: Yoneda f a -> f a Source