{-# LANGUAGE CPP #-} {-# OPTIONS_GHC -fno-warn-orphans #-} #ifndef MIN_VERSION_base #define MIN_VERSION_base(x,y,z) 1 #endif ----------------------------------------------------------------------------- -- | -- Module : Control.Lens.Internal.Instances -- Copyright : (C) 2012-2014 Edward Kmett -- License : BSD-style (see the file LICENSE) -- Maintainer : Edward Kmett <ekmett@gmail.com> -- Stability : experimental -- Portability : non-portable -- -- This module includes orphan instances for @(,)@, 'Either' and 'Const' that -- should be supplied by base. ---------------------------------------------------------------------------- module Control.Lens.Internal.Instances () where import Control.Applicative import Data.Semigroup.Foldable import Data.Semigroup.Traversable #if !(MIN_VERSION_base(4,7,0)) import Data.Monoid import Data.Foldable import Data.Traversable #endif ------------------------------------------------------------------------------- -- Orphan Instances ------------------------------------------------------------------------------- #if !(MIN_VERSION_base(4,7,0)) instance Foldable ((,) b) where foldMap f (_, a) = f a instance Traversable ((,) b) where traverse f (b, a) = (,) b <$> f a instance Foldable (Either a) where foldMap _ (Left _) = mempty foldMap f (Right a) = f a instance Traversable (Either a) where traverse _ (Left b) = pure (Left b) traverse f (Right a) = Right <$> f a instance Foldable (Const m) where foldMap _ _ = mempty instance Traversable (Const m) where traverse _ (Const m) = pure $ Const m #endif instance Foldable1 ((,) b) where foldMap1 f (_, a) = f a instance Traversable1 ((,) b) where traverse1 f (b, a) = (,) b <$> f a