Biff.hs

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-- |
-- Module	: Control.Bifunctor.Biff
-- Copyright 	: 2008 Edward Kmett
-- License	: BSD3
--
-- Maintainer	: Edward Kmett <ekmett@gmail.com>
-- Stability	: experimental
-- Portability	: portable
--
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module Control.Bifunctor.Biff 
	( module Control.Bifunctor.Monoidal
	, BiffB(..)
	) where

import Control.Bifunctor.Monoidal

newtype BiffB p f g a b = BiffB { runBiffB :: p (f a) (g b) } 

instance (Functor f, Bifunctor p, Functor g) => Bifunctor (BiffB p f g) where
	bimap f g = BiffB . bimap (fmap f) (fmap g) . runBiffB

instance (Functor f, Braided p) => Braided (BiffB p f f) where
	braid = BiffB . braid . runBiffB

instance (Functor f, Symmetric p) => Symmetric (BiffB p f f) 

instance (Functor f, Bifunctor p, Functor g) => Functor (BiffB p f g a) where
	fmap f = bimap id f