{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE TypeSynonymInstances #-}
#if __GLASGOW_HASKELL__ >= 701
{-# LANGUAGE DefaultSignatures #-}
#endif
#if __GLASGOW_HASKELL__ >= 705
{-# LANGUAGE PolyKinds #-}
#endif
#if __GLASGOW_HASKELL__ >= 708
{-# LANGUAGE EmptyCase #-}
#endif
#if __GLASGOW_HASKELL__ >= 710
{-# LANGUAGE Safe #-}
#elif __GLASGOW_HASKELL__ >= 701
{-# LANGUAGE Trustworthy #-}
#endif
module Generics.Deriving.Traversable (
GTraversable(..)
, gtraversedefault
, GTraversable'(..)
) where
import Control.Applicative (Const, WrappedMonad(..), ZipList)
#if !(MIN_VERSION_base(4,8,0))
import Control.Applicative (Applicative(..), (<$>))
#endif
import qualified Data.Monoid as Monoid (First, Last, Product, Sum)
import Data.Monoid (Dual)
import Generics.Deriving.Base
import Generics.Deriving.Foldable
import Generics.Deriving.Functor
#if MIN_VERSION_base(4,4,0)
import Data.Complex (Complex)
#endif
#if MIN_VERSION_base(4,6,0)
import Data.Ord (Down)
#else
import GHC.Exts (Down)
#endif
#if MIN_VERSION_base(4,7,0)
import Data.Proxy (Proxy)
#endif
#if MIN_VERSION_base(4,8,0)
import Data.Functor.Identity (Identity)
#endif
#if MIN_VERSION_base(4,9,0)
import qualified Data.Functor.Product as Functor (Product)
import qualified Data.Functor.Sum as Functor (Sum)
import Data.List.NonEmpty (NonEmpty)
import qualified Data.Semigroup as Semigroup (First, Last)
import Data.Semigroup (Arg, Max, Min, WrappedMonoid)
#endif
class GTraversable' t where
gtraverse' :: Applicative f => (a -> f b) -> t a -> f (t b)
instance GTraversable' V1 where
gtraverse' _ x = pure $ case x of
#if __GLASGOW_HASKELL__ >= 708
{}
#else
!_ -> error "Void gtraverse"
#endif
instance GTraversable' U1 where
gtraverse' _ U1 = pure U1
instance GTraversable' Par1 where
gtraverse' f (Par1 a) = Par1 <$> f a
instance GTraversable' (K1 i c) where
gtraverse' _ (K1 a) = pure (K1 a)
instance (GTraversable f) => GTraversable' (Rec1 f) where
gtraverse' f (Rec1 a) = Rec1 <$> gtraverse f a
instance (GTraversable' f) => GTraversable' (M1 i c f) where
gtraverse' f (M1 a) = M1 <$> gtraverse' f a
instance (GTraversable' f, GTraversable' g) => GTraversable' (f :+: g) where
gtraverse' f (L1 a) = L1 <$> gtraverse' f a
gtraverse' f (R1 a) = R1 <$> gtraverse' f a
instance (GTraversable' f, GTraversable' g) => GTraversable' (f :*: g) where
gtraverse' f (a :*: b) = (:*:) <$> gtraverse' f a <*> gtraverse' f b
instance (GTraversable f, GTraversable' g) => GTraversable' (f :.: g) where
gtraverse' f (Comp1 x) = Comp1 <$> gtraverse (gtraverse' f) x
instance GTraversable' UAddr where
gtraverse' _ (UAddr a) = pure (UAddr a)
instance GTraversable' UChar where
gtraverse' _ (UChar c) = pure (UChar c)
instance GTraversable' UDouble where
gtraverse' _ (UDouble d) = pure (UDouble d)
instance GTraversable' UFloat where
gtraverse' _ (UFloat f) = pure (UFloat f)
instance GTraversable' UInt where
gtraverse' _ (UInt i) = pure (UInt i)
instance GTraversable' UWord where
gtraverse' _ (UWord w) = pure (UWord w)
class (GFunctor t, GFoldable t) => GTraversable t where
gtraverse :: Applicative f => (a -> f b) -> t a -> f (t b)
#if __GLASGOW_HASKELL__ >= 701
default gtraverse :: (Generic1 t, GTraversable' (Rep1 t), Applicative f)
=> (a -> f b) -> t a -> f (t b)
gtraverse = gtraversedefault
#endif
gsequenceA :: Applicative f => t (f a) -> f (t a)
gsequenceA = gtraverse id
gmapM :: Monad m => (a -> m b) -> t a -> m (t b)
gmapM f = unwrapMonad . gtraverse (WrapMonad . f)
gsequence :: Monad m => t (m a) -> m (t a)
gsequence = gmapM id
gtraversedefault :: (Generic1 t, GTraversable' (Rep1 t), Applicative f)
=> (a -> f b) -> t a -> f (t b)
gtraversedefault f x = to1 <$> gtraverse' f (from1 x)
instance GTraversable ((,) a) where
gtraverse = gtraversedefault
instance GTraversable [] where
gtraverse = gtraversedefault
#if MIN_VERSION_base(4,9,0)
instance GTraversable (Arg a) where
gtraverse = gtraversedefault
#endif
#if MIN_VERSION_base(4,4,0)
instance GTraversable Complex where
gtraverse = gtraversedefault
#endif
instance GTraversable (Const m) where
gtraverse = gtraversedefault
instance GTraversable Down where
gtraverse = gtraversedefault
instance GTraversable Dual where
gtraverse = gtraversedefault
instance GTraversable (Either a) where
gtraverse = gtraversedefault
instance GTraversable Monoid.First where
gtraverse = gtraversedefault
#if MIN_VERSION_base(4,9,0)
instance GTraversable (Semigroup.First) where
gtraverse = gtraversedefault
#endif
#if MIN_VERSION_base(4,8,0)
instance GTraversable Identity where
gtraverse = gtraversedefault
#endif
instance GTraversable Monoid.Last where
gtraverse = gtraversedefault
#if MIN_VERSION_base(4,9,0)
instance GTraversable Semigroup.Last where
gtraverse = gtraversedefault
instance GTraversable Max where
gtraverse = gtraversedefault
#endif
instance GTraversable Maybe where
gtraverse = gtraversedefault
#if MIN_VERSION_base(4,9,0)
instance GTraversable Min where
gtraverse = gtraversedefault
instance GTraversable NonEmpty where
gtraverse = gtraversedefault
#endif
instance GTraversable Monoid.Product where
gtraverse = gtraversedefault
#if MIN_VERSION_base(4,9,0)
instance (GTraversable f, GTraversable g) => GTraversable (Functor.Product f g) where
gtraverse = gtraversedefault
#endif
#if MIN_VERSION_base(4,7,0)
instance GTraversable Proxy where
gtraverse = gtraversedefault
#endif
instance GTraversable Monoid.Sum where
gtraverse = gtraversedefault
#if MIN_VERSION_base(4,9,0)
instance (GTraversable f, GTraversable g) => GTraversable (Functor.Sum f g) where
gtraverse = gtraversedefault
instance GTraversable WrappedMonoid where
gtraverse = gtraversedefault
#endif
instance GTraversable ZipList where
gtraverse = gtraversedefault