pandora-0.3.0: Pandora/Paradigm/Primary/Functor/Equivalence.hs

module Pandora.Paradigm.Primary.Functor.Equivalence where

import Pandora.Pattern.Category (($))
import Pandora.Pattern.Functor.Contravariant (Contravariant ((>$<)))
import Pandora.Paradigm.Primary.Object.Boolean (Boolean)

data Equivalence a = Equivalence (a -> a -> Boolean)

instance Contravariant Equivalence where
	f >$< Equivalence g = Equivalence $ \x y -> g (f x) (f y)