kan-extensions-3.0: Kan extensions, the Yoneda lemma, and (co)density (co)monads

Portabilitynon-portable (GADTs, MPTCs)
Stabilityexperimental
MaintainerEdward Kmett <ekmett@gmail.com>
Safe HaskellNone

Control.Comonad.Density

Description

The density comonad for a functor. aka the comonad generated by a functor The ''density'' term dates back to Dubuc''s 1974 thesis. The term ''monad genererated by a functor'' dates back to 1972 in Street''s ''Formal Theory of Monads''.

Synopsis

Documentation

data Density k a whereSource

Constructors

Density :: (k b -> a) -> k b -> Density k a 

liftDensity :: Comonad w => w a -> Density w aSource

The natural isomorphism between a comonad w and the comonad generated by w (forwards).