    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Data.Bifunctor
    -- Copyright   :  (C) 2008-2013 Edward Kmett,
    -- License     :  BSD-style (see the file LICENSE)
    --
    -- Maintainer  :  Edward Kmett <ekmett@gmail.com>
    -- Stability   :  provisional
    -- Portability :  portable
    --
    ----------------------------------------------------------------------------
    module Data.Bifunctor.Wrapped
      ( WrappedBifunctor(..)
      ) where

    import Control.Applicative
    import Data.Biapplicative
    import Data.Bifoldable
    import Data.Bifunctor.Apply
    import Data.Bitraversable
    import Data.Foldable
    import Data.Monoid
    import Data.Semigroup.Bifoldable
    import Data.Semigroup.Bitraversable
    import Data.Traversable

    -- | Make a 'Functor' over the second argument of a 'Bifunctor'.
    newtype WrappedBifunctor p a b = WrapBifunctor { unwrapBifunctor :: p a b }
      deriving (Eq,Ord,Show,Read)

    instance Bifunctor p => Bifunctor (WrappedBifunctor p) where
      first f = WrapBifunctor . first f . unwrapBifunctor
      {-# INLINE first #-}
      second f = WrapBifunctor . second f . unwrapBifunctor
      {-# INLINE second #-}
      bimap f g = WrapBifunctor . bimap f g . unwrapBifunctor
      {-# INLINE bimap #-}

    instance Bifunctor p => Functor (WrappedBifunctor p a) where
      fmap f = WrapBifunctor . second f . unwrapBifunctor
      {-# INLINE fmap #-}

    instance Biapply p => Biapply (WrappedBifunctor p) where
      WrapBifunctor fg <<.>> WrapBifunctor xy = WrapBifunctor (fg <<.>> xy)
      {-# INLINE (<<.>>) #-}

    instance Biapplicative p => Biapplicative (WrappedBifunctor p) where
      bipure a b = WrapBifunctor (bipure a b)
      {-# INLINE bipure #-}
      WrapBifunctor fg <<*>> WrapBifunctor xy = WrapBifunctor (fg <<*>> xy)
      {-# INLINE (<<*>>) #-}

    instance Bifoldable p => Foldable (WrappedBifunctor p a) where
      foldMap f = bifoldMap (const mempty) f . unwrapBifunctor
      {-# INLINE foldMap #-}

    instance Bifoldable p => Bifoldable (WrappedBifunctor p) where
      bifoldMap f g = bifoldMap f g . unwrapBifunctor
      {-# INLINE bifoldMap #-}

    instance Bitraversable p => Traversable (WrappedBifunctor p a) where
      traverse f = fmap WrapBifunctor . bitraverse pure f . unwrapBifunctor
      {-# INLINE traverse #-}

    instance Bitraversable p => Bitraversable (WrappedBifunctor p) where
      bitraverse f g = fmap WrapBifunctor . bitraverse f g . unwrapBifunctor
      {-# INLINE bitraverse #-}

    instance Bifoldable1 p => Bifoldable1 (WrappedBifunctor p) where
      bifoldMap1 f g = bifoldMap1 f g . unwrapBifunctor
      {-# INLINE bifoldMap1 #-}

    instance Bitraversable1 p => Bitraversable1 (WrappedBifunctor p) where
      bitraverse1 f g = fmap WrapBifunctor . bitraverse1 f g . unwrapBifunctor
      {-# INLINE bitraverse1 #-}