pandora-0.4.5: Pandora/Paradigm/Primary/Functor/Convergence.hs

module Pandora.Paradigm.Primary.Functor.Convergence where

import Pandora.Pattern.Category (($), (#))
import Pandora.Pattern.Functor.Contravariant (Contravariant ((->$<-)))
import Pandora.Paradigm.Primary.Algebraic ()

data Convergence r a = Convergence (a -> a -> r)

instance Contravariant (Convergence r) (->) (->) where
	f ->$<- Convergence g = Convergence $ \x y -> g # f x # f y