{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE Safe #-}
{-# LANGUAGE TypeOperators #-}

#if __GLASGOW_HASKELL__ >= 706
{-# LANGUAGE PolyKinds #-}
#endif

#if __GLASGOW_HASKELL__ >= 708
{-# LANGUAGE EmptyCase #-}
#endif

-----------------------------------------------------------------------------
-- |
-- Module      :  Control.DeepSeq
-- Copyright   :  (c) The University of Glasgow 2001-2009
-- License     :  BSD-style (see the file LICENSE)
--
-- Maintainer  :  libraries@haskell.org
-- Stability   :  stable
-- Portability :  portable
--
-- This module provides overloaded functions, such as 'deepseq' and
-- 'rnf', for fully evaluating data structures (that is, evaluating to
-- \"Normal Form\").
--
-- A typical use is to prevent resource leaks in lazy IO programs, by
-- forcing all characters from a file to be read. For example:
--
-- > import System.IO
-- > import Control.DeepSeq
-- > import Control.Exception (evaluate)
-- >
-- > readFile' :: FilePath -> IO String
-- > readFile' fn = do
-- >     h <- openFile fn ReadMode
-- >     s <- hGetContents h
-- >     evaluate (rnf s)
-- >     hClose h
-- >     return s
--
-- __Note__: The example above should rather be written in terms of
-- 'Control.Exception.bracket' to ensure releasing file-descriptors in
-- a timely matter (see the description of 'force' for an example).
--
-- 'deepseq' differs from 'seq' as it traverses data structures deeply,
-- for example, 'seq' will evaluate only to the first constructor in
-- the list:
--
-- > > [1,2,undefined] `seq` 3
-- > 3
--
-- While 'deepseq' will force evaluation of all the list elements:
--
-- > > [1,2,undefined] `deepseq` 3
-- > *** Exception: Prelude.undefined
--
-- Another common use is to ensure any exceptions hidden within lazy
-- fields of a data structure do not leak outside the scope of the
-- exception handler, or to force evaluation of a data structure in one
-- thread, before passing to another thread (preventing work moving to
-- the wrong threads).
--
-- @since 1.1.0.0
module Control.DeepSeq (
     -- * 'NFData' class
     NFData(rnf),
     -- * Helper functions
     deepseq,
     force,
     ($!!),
     (<$!!>),
     rwhnf,

     -- * Liftings of the 'NFData' class
     -- ** For unary constructors
     NFData1(liftRnf), rnf1,
     -- ** For binary constructors
     NFData2(liftRnf2), rnf2,
  ) where

import Control.Applicative
import Control.Concurrent ( ThreadId, MVar )
import Control.Exception ( MaskingState(..) )
import Data.IORef
import Data.STRef
import Data.Int
import Data.Word
import Data.Ratio
import Data.Complex
import Data.Array
import Data.Fixed
import Data.Version
import Data.Monoid as Mon
import Data.Typeable ( TypeRep, TyCon )
import Data.Unique ( Unique )
import Foreign.Ptr
import Foreign.C.Types
import System.Exit ( ExitCode(..) )
import System.Mem.StableName ( StableName )

#if MIN_VERSION_base(4,6,0)
import Data.Ord ( Down(Down) )
#else
import Control.DeepSeq.BackDoor ( Down(Down) )
#endif

#if MIN_VERSION_base(4,7,0)
import Data.Proxy ( Proxy(Proxy) )
#endif

#if MIN_VERSION_base(4,10,0)
import Data.Type.Equality ( (:~:), (:~~:) )
#elif MIN_VERSION_base(4,9,0)
import Data.Type.Equality ( (:~:) )
#elif MIN_VERSION_base(4,7,0)
import Control.DeepSeq.BackDoor ( (:~:) )
#endif

#if MIN_VERSION_base(4,8,0)
import Data.Functor.Identity ( Identity(..) )
import Data.Typeable ( rnfTypeRep, rnfTyCon )
import Data.Void ( Void, absurd )
import Numeric.Natural ( Natural )
#else
import Data.Typeable ( typeRepTyCon, typeRepArgs, tyConPackage, tyConModule, tyConName )
#endif

#if MIN_VERSION_base(4,9,0)
import Data.List.NonEmpty ( NonEmpty (..) )
import Data.Semigroup as Semi
#endif

#if MIN_VERSION_base(4,9,0)
import GHC.Stack.Types ( CallStack(..), SrcLoc(..) )
import Data.Functor.Compose
import qualified Data.Functor.Sum as Functor
import qualified Data.Functor.Product as Functor
#elif MIN_VERSION_base(4,8,1)
import GHC.Stack ( CallStack(..) )
import GHC.SrcLoc ( SrcLoc(..) )
#endif

import GHC.Fingerprint.Type ( Fingerprint(..) )
import GHC.Generics

-- | Hidden internal type-class
class GNFData arity f where
  grnf :: RnfArgs arity a -> f a -> ()

instance GNFData arity V1 where
#if __GLASGOW_HASKELL__ >= 708
  grnf _ x = case x of {}
#else
  grnf _ !_ = error "Control.DeepSeq.rnf: uninhabited type"
#endif

data Zero
data One

data RnfArgs arity a where
  RnfArgs0 :: RnfArgs Zero a
  RnfArgs1  :: (a -> ()) -> RnfArgs One a

instance GNFData arity U1 where
  grnf _ U1 = ()

instance NFData a => GNFData arity (K1 i a) where
  grnf _ = rnf . unK1
  {-# INLINEABLE grnf #-}

instance GNFData arity a => GNFData arity (M1 i c a) where
  grnf args = grnf args . unM1
  {-# INLINEABLE grnf #-}

instance (GNFData arity a, GNFData arity b) => GNFData arity (a :*: b) where
  grnf args (x :*: y) = grnf args x `seq` grnf args y
  {-# INLINEABLE grnf #-}

instance (GNFData arity a, GNFData arity b) => GNFData arity (a :+: b) where
  grnf args (L1 x) = grnf args x
  grnf args (R1 x) = grnf args x
  {-# INLINEABLE grnf #-}

instance GNFData One Par1 where
    grnf (RnfArgs1 r) = r . unPar1

instance NFData1 f => GNFData One (Rec1 f) where
    grnf (RnfArgs1 r) = liftRnf r . unRec1

instance (NFData1 f, GNFData One g) => GNFData One (f :.: g) where
    grnf args = liftRnf (grnf args) . unComp1

infixr 0 $!!

-- | 'deepseq': fully evaluates the first argument, before returning the
-- second.
--
-- The name 'deepseq' is used to illustrate the relationship to 'seq':
-- where 'seq' is shallow in the sense that it only evaluates the top
-- level of its argument, 'deepseq' traverses the entire data structure
-- evaluating it completely.
--
-- 'deepseq' can be useful for forcing pending exceptions,
-- eradicating space leaks, or forcing lazy I/O to happen.  It is
-- also useful in conjunction with parallel Strategies (see the
-- @parallel@ package).
--
-- There is no guarantee about the ordering of evaluation.  The
-- implementation may evaluate the components of the structure in
-- any order or in parallel.  To impose an actual order on
-- evaluation, use 'pseq' from "Control.Parallel" in the
-- @parallel@ package.
--
-- @since 1.1.0.0
deepseq :: NFData a => a -> b -> b
deepseq a b = rnf a `seq` b

-- | the deep analogue of '$!'.  In the expression @f $!! x@, @x@ is
-- fully evaluated before the function @f@ is applied to it.
--
-- @since 1.2.0.0
($!!) :: (NFData a) => (a -> b) -> a -> b
f $!! x = x `deepseq` f x

-- | a variant of 'deepseq' that is useful in some circumstances:
--
-- > force x = x `deepseq` x
--
-- @force x@ fully evaluates @x@, and then returns it.  Note that
-- @force x@ only performs evaluation when the value of @force x@
-- itself is demanded, so essentially it turns shallow evaluation into
-- deep evaluation.
--
-- 'force' can be conveniently used in combination with @ViewPatterns@:
--
-- > {-# LANGUAGE BangPatterns, ViewPatterns #-}
-- > import Control.DeepSeq
-- >
-- > someFun :: ComplexData -> SomeResult
-- > someFun (force -> !arg) = {- 'arg' will be fully evaluated -}
--
-- Another useful application is to combine 'force' with
-- 'Control.Exception.evaluate' in order to force deep evaluation
-- relative to other 'IO' operations:
--
-- > import Control.Exception (evaluate)
-- > import Control.DeepSeq
-- >
-- > main = do
-- >   result <- evaluate $ force $ pureComputation
-- >   {- 'result' will be fully evaluated at this point -}
-- >   return ()
--
-- Finally, here's an exception safe variant of the @readFile'@ example:
--
-- > readFile' :: FilePath -> IO String
-- > readFile' fn = bracket (openFile fn ReadMode) hClose $ \h ->
-- >                        evaluate . force =<< hGetContents h
--
-- @since 1.2.0.0
force :: (NFData a) => a -> a
force x = x `deepseq` x

-- | Deeply strict version of 'Control.Applicative.<$>'.
--
-- @since 1.4.3.0
(<$!!>) :: (Monad m, NFData b) => (a -> b) -> m a -> m b
#if MIN_VERSION_base(4,8,0)
-- Minor optimisation for AMP; this avoids the redundant indirection
-- through 'return' in case GHC isn't smart enough to optimise it away
-- on its own
f <$!!> m = m >>= \x -> pure $!! f x
#else
f <$!!> m = m >>= \x -> return $!! f x
#endif
infixl 4 <$!!>

-- | Reduce to weak head normal form
--
-- Equivalent to @\\x -> 'seq' x ()@.
--
-- Useful for defining 'NFData' for types for which NF=WHNF holds.
--
-- > data T = C1 | C2 | C3
-- > instance NFData T where rnf = rwhnf
--
-- @since 1.4.3.0
rwhnf :: a -> ()
rwhnf = (`seq` ())
{-# INLINE rwhnf #-}

-- Note: the 'rwhnf' is defined point-free to help aggressive inlining

-- | A class of types that can be fully evaluated.
--
-- @since 1.1.0.0
class NFData a where
    -- | 'rnf' should reduce its argument to normal form (that is, fully
    -- evaluate all sub-components), and then return '()'.
    --
    -- === 'Generic' 'NFData' deriving
    --
    -- Starting with GHC 7.2, you can automatically derive instances
    -- for types possessing a 'Generic' instance.
    --
    -- Note: 'Generic1' can be auto-derived starting with GHC 7.4
    --
    -- > {-# LANGUAGE DeriveGeneric #-}
    -- >
    -- > import GHC.Generics (Generic, Generic1)
    -- > import Control.DeepSeq
    -- >
    -- > data Foo a = Foo a String
    -- >              deriving (Eq, Generic, Generic1)
    -- >
    -- > instance NFData a => NFData (Foo a)
    -- > instance NFData1 Foo
    -- >
    -- > data Colour = Red | Green | Blue
    -- >               deriving Generic
    -- >
    -- > instance NFData Colour
    --
    -- Starting with GHC 7.10, the example above can be written more
    -- concisely by enabling the new @DeriveAnyClass@ extension:
    --
    -- > {-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
    -- >
    -- > import GHC.Generics (Generic)
    -- > import Control.DeepSeq
    -- >
    -- > data Foo a = Foo a String
    -- >              deriving (Eq, Generic, Generic1, NFData, NFData1)
    -- >
    -- > data Colour = Red | Green | Blue
    -- >               deriving (Generic, NFData)
    -- >
    --
    -- === Compatibility with previous @deepseq@ versions
    --
    -- Prior to version 1.4.0.0, the default implementation of the 'rnf'
    -- method was defined as
    --
    -- @'rnf' a = 'seq' a ()@
    --
    -- However, starting with @deepseq-1.4.0.0@, the default
    -- implementation is based on @DefaultSignatures@ allowing for
    -- more accurate auto-derived 'NFData' instances. If you need the
    -- previously used exact default 'rnf' method implementation
    -- semantics, use
    --
    -- > instance NFData Colour where rnf x = seq x ()
    --
    -- or alternatively
    --
    -- > instance NFData Colour where rnf = rwhnf
    --
    -- or
    --
    -- > {-# LANGUAGE BangPatterns #-}
    -- > instance NFData Colour where rnf !_ = ()
    --
    rnf :: a -> ()

    default rnf :: (Generic a, GNFData Zero (Rep a)) => a -> ()
    rnf = grnf RnfArgs0 . from

-- | A class of functors that can be fully evaluated.
--
-- @since 1.4.3.0
class NFData1 f where
    -- | 'liftRnf' should reduce its argument to normal form (that is, fully
    -- evaluate all sub-components), given an argument to reduce @a@ arguments,
    -- and then return '()'.
    --
    -- See 'rnf' for the generic deriving.
    liftRnf :: (a -> ()) -> f a -> ()

    default liftRnf :: (Generic1 f, GNFData One (Rep1 f)) => (a -> ()) -> f a -> ()
    liftRnf r = grnf (RnfArgs1 r) . from1

-- | Lift the standard 'rnf' function through the type constructor.
--
-- @since 1.4.3.0
rnf1 :: (NFData1 f, NFData a) => f a -> ()
rnf1 = liftRnf rnf

-- | A class of bifunctors that can be fully evaluated.
--
-- @since 1.4.3.0
class NFData2 p where
    -- | 'liftRnf2' should reduce its argument to normal form (that
    -- is, fully evaluate all sub-components), given functions to
    -- reduce @a@ and @b@ arguments respectively, and then return '()'.
    --
    -- __Note__: Unlike for the unary 'liftRnf', there is currently no
    -- support for generically deriving 'liftRnf2'.
    liftRnf2 :: (a -> ()) -> (b -> ()) -> p a b -> ()

-- | Lift the standard 'rnf' function through the type constructor.
--
-- @since 1.4.3.0
rnf2 :: (NFData2 p, NFData a, NFData b) => p a b -> ()
rnf2 = liftRnf2 rnf rnf


instance NFData Int      where rnf = rwhnf
instance NFData Word     where rnf = rwhnf
instance NFData Integer  where rnf = rwhnf
instance NFData Float    where rnf = rwhnf
instance NFData Double   where rnf = rwhnf

instance NFData Char     where rnf = rwhnf
instance NFData Bool     where rnf = rwhnf
instance NFData Ordering where rnf = rwhnf
instance NFData ()       where rnf = rwhnf

instance NFData Int8     where rnf = rwhnf
instance NFData Int16    where rnf = rwhnf
instance NFData Int32    where rnf = rwhnf
instance NFData Int64    where rnf = rwhnf

instance NFData Word8    where rnf = rwhnf
instance NFData Word16   where rnf = rwhnf
instance NFData Word32   where rnf = rwhnf
instance NFData Word64   where rnf = rwhnf

-- | @since 1.4.4.0
instance NFData MaskingState where rnf = rwhnf

#if MIN_VERSION_base(4,7,0)
-- |@since 1.4.0.0
instance NFData (Proxy a) where rnf Proxy = ()
-- |@since 1.4.3.0
instance NFData1 Proxy    where liftRnf _ Proxy = ()

-- | @since 1.4.3.0
instance NFData (a :~: b) where rnf = rwhnf
-- | @since 1.4.3.0
instance NFData1 ((:~:) a) where liftRnf _ = rwhnf
-- | @since 1.4.3.0
instance NFData2 (:~:) where liftRnf2 _ _ = rwhnf
#endif

#if MIN_VERSION_base(4,10,0)
-- | @since 1.4.3.0
instance NFData (a :~~: b) where rnf = rwhnf
-- | @since 1.4.3.0
instance NFData1 ((:~~:) a) where liftRnf _ = rwhnf
-- | @since 1.4.3.0
instance NFData2 (:~~:) where liftRnf2 _ _ = rwhnf
#endif

#if MIN_VERSION_base(4,8,0)
-- |@since 1.4.0.0
instance NFData a => NFData (Identity a) where
    rnf = rnf1

-- |@since 1.4.3.0
instance NFData1 Identity where
    liftRnf r = r . runIdentity

-- | Defined as @'rnf' = 'absurd'@.
--
-- @since 1.4.0.0
instance NFData Void where
    rnf = absurd

-- |@since 1.4.0.0
instance NFData Natural  where rnf = rwhnf
#endif

-- |@since 1.3.0.0
instance NFData (Fixed a) where rnf = rwhnf
-- |@since 1.4.3.0
instance NFData1 Fixed where liftRnf _ = rwhnf

-- |This instance is for convenience and consistency with 'seq'.
-- This assumes that WHNF is equivalent to NF for functions.
--
-- @since 1.3.0.0
instance NFData (a -> b) where rnf = rwhnf

--Rational and complex numbers.

#if MIN_VERSION_base(4,9,0)
-- | Available on @base >=4.9@
--
-- @since 1.4.3.0
instance NFData1 Ratio where
  liftRnf r x = r (numerator x) `seq` r (denominator x)

-- | @since 1.4.3.0
instance (NFData1 f, NFData1 g) => NFData1 (Compose f g) where
  liftRnf r = liftRnf (liftRnf r) . getCompose

-- | @since 1.4.3.0
instance (NFData1 f, NFData1 g, NFData a) => NFData (Compose f g a) where
  rnf = rnf1

-- | @since 1.4.3.0
instance (NFData1 f, NFData1 g) => NFData1 (Functor.Sum f g) where
  liftRnf rnf0 (Functor.InL l) = liftRnf rnf0 l
  liftRnf rnf0 (Functor.InR r) = liftRnf rnf0 r

-- | @since 1.4.3.0
instance (NFData1 f, NFData1 g, NFData a) => NFData (Functor.Sum f g a) where
  rnf = rnf1

-- | @since 1.4.3.0
instance (NFData1 f, NFData1 g) => NFData1 (Functor.Product f g) where
  liftRnf rnf0 (Functor.Pair f g) = liftRnf rnf0 f `seq` liftRnf rnf0 g

-- | @since 1.4.3.0
instance (NFData1 f, NFData1 g, NFData a) => NFData (Functor.Product f g a) where
  rnf = rnf1

instance NFData a => NFData (Ratio a) where
#else
instance (Integral a, NFData a) => NFData (Ratio a) where
#endif
  rnf x = rnf (numerator x, denominator x)

instance (NFData a) => NFData (Complex a) where
  rnf (x:+y) = rnf x `seq`
               rnf y `seq`
               ()

instance NFData a => NFData (Maybe a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Maybe where
    liftRnf _r Nothing  = ()
    liftRnf  r (Just x) = r x

instance (NFData a, NFData b) => NFData (Either a b) where rnf = rnf1
-- |@since 1.4.3.0
instance (NFData a) => NFData1 (Either a) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance NFData2 Either where
    liftRnf2  l _r (Left x)  = l x
    liftRnf2 _l  r (Right y) = r y

-- |@since 1.3.0.0
instance NFData Data.Version.Version where
    rnf (Data.Version.Version branch tags) = rnf branch `seq` rnf tags

instance NFData a => NFData [a] where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 [] where
    liftRnf r = go
      where
        go [] = ()
        go (x:xs) = r x `seq` go xs

-- |@since 1.4.0.0
instance NFData a => NFData (ZipList a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 ZipList where
    liftRnf r = liftRnf r . getZipList

-- |@since 1.4.0.0
instance NFData a => NFData (Const a b) where
    rnf = rnf . getConst
-- |@since 1.4.3.0
instance NFData a => NFData1 (Const a) where
    liftRnf _ = rnf . getConst
-- |@since 1.4.3.0
instance NFData2 Const where
    liftRnf2 r _ = r . getConst

-- We should use MIN_VERSION array(0,5,1,1) but that's not possible.
-- There isn't an underscore to not break C preprocessor
#if __GLASGOW_HASKELL__ >= 711
instance (NFData a, NFData b) => NFData (Array a b) where
#else
instance (Ix a, NFData a, NFData b) => NFData (Array a b) where
#endif
    rnf x = rnf (bounds x, Data.Array.elems x)

#if __GLASGOW_HASKELL__ >= 711
-- |@since 1.4.3.0
instance (NFData a) => NFData1 (Array a) where
#else
-- |@since 1.4.3.0
instance (Ix a, NFData a) => NFData1 (Array a) where
#endif
    liftRnf r x = rnf (bounds x) `seq` liftRnf r (Data.Array.elems x)

#if __GLASGOW_HASKELL__ >= 711
-- |@since 1.4.3.0
instance NFData2 Array where
    liftRnf2 r r' x = liftRnf2 r r (bounds x) `seq` liftRnf r' (Data.Array.elems x)
#endif

-- |@since 1.4.0.0
instance NFData a => NFData (Down a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Down where
    liftRnf r (Down x) = r x

-- |@since 1.4.0.0
instance NFData a => NFData (Dual a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Dual where
    liftRnf r (Dual x) = r x

-- |@since 1.4.0.0
instance NFData a => NFData (Mon.First a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Mon.First  where
    liftRnf r (Mon.First x) = liftRnf r x

-- |@since 1.4.0.0
instance NFData a => NFData (Mon.Last a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Mon.Last  where
    liftRnf r (Mon.Last  x) = liftRnf r x

-- |@since 1.4.0.0
instance NFData Any where rnf = rnf . getAny

-- |@since 1.4.0.0
instance NFData All where rnf = rnf . getAll

-- |@since 1.4.0.0
instance NFData a => NFData (Sum a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Sum where
    liftRnf r (Sum x) = r x

-- |@since 1.4.0.0
instance NFData a => NFData (Product a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Product where
    liftRnf r (Product x) = r x

-- |@since 1.4.0.0
instance NFData (StableName a) where
    rnf = rwhnf -- assumes `data StableName a = StableName (StableName# a)`
-- |@since 1.4.3.0
instance NFData1 StableName where
    liftRnf _ = rwhnf

-- |@since 1.4.0.0
instance NFData ThreadId where
    rnf = rwhnf -- assumes `data ThreadId = ThreadId ThreadId#`

-- |@since 1.4.0.0
instance NFData Unique where
    rnf = rwhnf -- assumes `newtype Unique = Unique Integer`

#if MIN_VERSION_base(4,8,0)
-- | __NOTE__: Prior to @deepseq-1.4.4.0@ this instance was only defined for @base-4.8.0.0@ and later.
--
-- @since 1.4.0.0
instance NFData TypeRep where
    rnf tyrep = rnfTypeRep tyrep

-- | __NOTE__: Prior to @deepseq-1.4.4.0@ this instance was only defined for @base-4.8.0.0@ and later.
--
-- @since 1.4.0.0
instance NFData TyCon where
    rnf tycon = rnfTyCon tycon
#else
-- | __NOTE__: Prior to @deepseq-1.4.4.0@ this instance was only defined for @base-4.8.0.0@ and later.
--
-- @since 1.4.0.0
instance NFData TypeRep where
    rnf tr = rnf (typeRepTyCon tr) `seq` rnf (typeRepArgs tr)

-- | __NOTE__: Prior to @deepseq-1.4.4.0@ this instance was only defined for @base-4.8.0.0@ and later.
--
-- @since 1.4.0.0
instance NFData TyCon where
    rnf tc = rnf (tyConPackage tc) `seq`
             rnf (tyConModule  tc) `seq`
             rnf (tyConName    tc)
#endif

-- | __NOTE__: Only strict in the reference and not the referenced value.
--
-- @since 1.4.2.0
instance NFData (IORef a) where
    rnf = rwhnf
-- |@since 1.4.3.0
instance NFData1 IORef where
    liftRnf _ = rwhnf

-- | __NOTE__: Only strict in the reference and not the referenced value.
--
-- @since 1.4.2.0
instance NFData (STRef s a) where
    rnf = rwhnf
-- |@since 1.4.3.0
instance NFData1 (STRef s) where
    liftRnf _ = rwhnf
-- |@since 1.4.3.0
instance NFData2 STRef where
    liftRnf2 _ _ = rwhnf

-- | __NOTE__: Only strict in the reference and not the referenced value.
--
-- @since 1.4.2.0
instance NFData (MVar a) where
  rnf = rwhnf
-- |@since 1.4.3.0
instance NFData1 MVar where
    liftRnf _ = rwhnf

----------------------------------------------------------------------------
-- GHC Specifics

-- |@since 1.4.0.0
instance NFData Fingerprint where
    rnf (Fingerprint _ _) = ()

----------------------------------------------------------------------------
-- Foreign.Ptr

-- |@since 1.4.2.0
instance NFData (Ptr a) where
    rnf = rwhnf
-- |@since 1.4.3.0
instance NFData1 Ptr where
    liftRnf _ = rwhnf

-- |@since 1.4.2.0
instance NFData (FunPtr a) where
    rnf = rwhnf
-- |@since 1.4.3.0
instance NFData1 FunPtr where
    liftRnf _ = rwhnf

----------------------------------------------------------------------------
-- Foreign.C.Types

-- |@since 1.4.0.0
instance NFData CChar where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CSChar where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CUChar where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CShort where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CUShort where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CInt where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CUInt where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CLong where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CULong where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CPtrdiff where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CSize where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CWchar where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CSigAtomic where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CLLong where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CULLong where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CIntPtr where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CUIntPtr where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CIntMax where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CUIntMax where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CClock where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CTime where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CUSeconds where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CSUSeconds where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CFloat where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CDouble where rnf = rwhnf

-- NOTE: The types `CFile`, `CFPos`, and `CJmpBuf` below are not
-- newtype wrappers rather defined as field-less single-constructor
-- types.

-- |@since 1.4.0.0
instance NFData CFile where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CFpos where rnf = rwhnf

-- |@since 1.4.0.0
instance NFData CJmpBuf where rnf = rwhnf

#if MIN_VERSION_base(4,10,0)
-- | @since 1.4.3.0
instance NFData CBool where rnf = rwhnf
#endif

----------------------------------------------------------------------------
-- System.Exit

-- |@since 1.4.2.0
instance NFData ExitCode where
  rnf (ExitFailure n) = rnf n
  rnf ExitSuccess     = ()

----------------------------------------------------------------------------
-- instances previously provided by semigroups package

#if MIN_VERSION_base(4,9,0)
-- |@since 1.4.2.0
instance NFData a => NFData (NonEmpty a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 NonEmpty where
  liftRnf r (x :| xs) = r x `seq` liftRnf r xs

-- |@since 1.4.2.0
instance NFData a => NFData (Min a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Min where
  liftRnf r (Min a) = r a

-- |@since 1.4.2.0
instance NFData a => NFData (Max a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Max where
  liftRnf r (Max a) = r a

-- |@since 1.4.2.0
instance (NFData a, NFData b) => NFData (Arg a b) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a) => NFData1 (Arg a) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance NFData2 Arg where
  liftRnf2 r r' (Arg a b) = r a `seq` r' b `seq` ()

-- |@since 1.4.2.0
instance NFData a => NFData (Semi.First a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Semi.First where
  liftRnf r (Semi.First a) = r a

-- |@since 1.4.2.0
instance NFData a => NFData (Semi.Last a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Semi.Last where
  liftRnf r (Semi.Last a) = r a

-- |@since 1.4.2.0
instance NFData m => NFData (WrappedMonoid m) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 WrappedMonoid where
  liftRnf r (WrapMonoid a) = r a

-- |@since 1.4.2.0
instance NFData a => NFData (Option a) where rnf = rnf1
-- |@since 1.4.3.0
instance NFData1 Option where
  liftRnf r (Option a) = liftRnf r a
#endif

----------------------------------------------------------------------------
-- GHC.Stack

#if MIN_VERSION_base(4,9,0)
-- |@since 1.4.2.0
instance NFData SrcLoc where
  rnf (SrcLoc a b c d e f g) = rnf a `seq` rnf b `seq` rnf c `seq`
                               rnf d `seq` rnf e `seq` rnf f `seq` rnf g

-- |@since 1.4.2.0
instance NFData CallStack where
  rnf EmptyCallStack = ()
  rnf (PushCallStack a b c) = rnf a `seq` rnf b `seq` rnf c
  rnf (FreezeCallStack a)   = rnf a

#elif MIN_VERSION_base(4,8,1)
-- |@since 1.4.2.0
instance NFData SrcLoc where
  -- base-4.8 didn't expose the 'SrcLoc' constructor
  rnf sl = rnf (srcLocPackage   sl) `seq`
           rnf (srcLocModule    sl) `seq`
           rnf (srcLocFile      sl) `seq`
           rnf (srcLocStartLine sl) `seq`
           rnf (srcLocStartCol  sl) `seq`
           rnf (srcLocEndLine   sl) `seq`
           rnf (srcLocEndCol    sl)

-- |@since 1.4.2.0
instance NFData CallStack where
  rnf = rnf . getCallStack
#endif

----------------------------------------------------------------------------
-- Tuples

instance (NFData a, NFData b) => NFData (a,b) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a) => NFData1 ((,) a) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance NFData2 (,) where
  liftRnf2 r r' (x,y) = r x `seq` r' y

-- Code below is generated, see generate-nfdata-tuple.hs
instance (NFData a1, NFData a2, NFData a3) =>
         NFData (a1, a2, a3) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2) =>
         NFData1 ((,,) a1 a2) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1) =>
         NFData2 ((,,) a1) where
  liftRnf2 r r' (x1,x2,x3) = rnf x1 `seq` r x2 `seq` r' x3

instance (NFData a1, NFData a2, NFData a3, NFData a4) =>
         NFData (a1, a2, a3, a4) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3) =>
         NFData1 ((,,,) a1 a2 a3) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1, NFData a2) =>
         NFData2 ((,,,) a1 a2) where
  liftRnf2 r r' (x1,x2,x3,x4) = rnf x1 `seq` rnf x2 `seq` r x3 `seq` r' x4

instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) =>
         NFData (a1, a2, a3, a4, a5) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4) =>
         NFData1 ((,,,,) a1 a2 a3 a4) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3) =>
         NFData2 ((,,,,) a1 a2 a3) where
  liftRnf2 r r' (x1,x2,x3,x4,x5) = rnf x1 `seq` rnf x2 `seq` rnf x3 `seq` r x4 `seq` r' x5

instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) =>
         NFData (a1, a2, a3, a4, a5, a6) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) =>
         NFData1 ((,,,,,) a1 a2 a3 a4 a5) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4) =>
         NFData2 ((,,,,,) a1 a2 a3 a4) where
  liftRnf2 r r' (x1,x2,x3,x4,x5,x6) = rnf x1 `seq` rnf x2 `seq` rnf x3 `seq` rnf x4 `seq` r x5 `seq` r' x6

instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) =>
         NFData (a1, a2, a3, a4, a5, a6, a7) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) =>
         NFData1 ((,,,,,,) a1 a2 a3 a4 a5 a6) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) =>
         NFData2 ((,,,,,,) a1 a2 a3 a4 a5) where
  liftRnf2 r r' (x1,x2,x3,x4,x5,x6,x7) = rnf x1 `seq` rnf x2 `seq` rnf x3 `seq` rnf x4 `seq` rnf x5 `seq` r x6 `seq` r' x7

instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7, NFData a8) =>
         NFData (a1, a2, a3, a4, a5, a6, a7, a8) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) =>
         NFData1 ((,,,,,,,) a1 a2 a3 a4 a5 a6 a7) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) =>
         NFData2 ((,,,,,,,) a1 a2 a3 a4 a5 a6) where
  liftRnf2 r r' (x1,x2,x3,x4,x5,x6,x7,x8) = rnf x1 `seq` rnf x2 `seq` rnf x3 `seq` rnf x4 `seq` rnf x5 `seq` rnf x6 `seq` r x7 `seq` r' x8

instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7, NFData a8, NFData a9) =>
         NFData (a1, a2, a3, a4, a5, a6, a7, a8, a9) where rnf = rnf2
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7, NFData a8) =>
         NFData1 ((,,,,,,,,) a1 a2 a3 a4 a5 a6 a7 a8) where liftRnf = liftRnf2 rnf
-- |@since 1.4.3.0
instance (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) =>
         NFData2 ((,,,,,,,,) a1 a2 a3 a4 a5 a6 a7) where
  liftRnf2 r r' (x1,x2,x3,x4,x5,x6,x7,x8,x9) = rnf x1 `seq` rnf x2 `seq` rnf x3 `seq` rnf x4 `seq` rnf x5 `seq` rnf x6 `seq` rnf x7 `seq` r x8 `seq` r' x9