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
Safe Haskell	Safe
Language	Haskell2010

Description

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 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: deepseq-1.1.0.0

NFData class

class NFData a where Source

A class of types that can be fully evaluated.

Since: deepseq-1.1.0.0

Minimal complete definition

Nothing

Methods

rnf :: a -> () Source

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

{-# LANGUAGE BangPatterns #-}
instance NFData Colour where rnf !_ = ()

default rnf :: (Generic a, GNFData Zero (Rep a)) => a -> () Source

Instances

Instances details

NFData ByteArray Source	Since: deepseq-1.4.7.0
Instance details Defined in Control.DeepSeq Methods rnf :: ByteArray -> () Source
NFData All Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: All -> () Source
NFData Any Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Any -> () Source
NFData TypeRep Source	NOTE: Prior to `deepseq-1.4.4.0` this instance was only defined for `base-4.8.0.0` and later. Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: TypeRep -> () Source
NFData Unique Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Unique -> () Source
NFData Version Source	Since: deepseq-1.3.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Version -> () Source
NFData Void Source	Defined as `rnf = absurd`. Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Void -> () Source
NFData CBool Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods rnf :: CBool -> () Source
NFData CChar Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CChar -> () Source
NFData CClock Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CClock -> () Source
NFData CDouble Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CDouble -> () Source
NFData CFile Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CFile -> () Source
NFData CFloat Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CFloat -> () Source
NFData CFpos Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CFpos -> () Source
NFData CInt Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CInt -> () Source
NFData CIntMax Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CIntMax -> () Source
NFData CIntPtr Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CIntPtr -> () Source
NFData CJmpBuf Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CJmpBuf -> () Source
NFData CLLong Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CLLong -> () Source
NFData CLong Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CLong -> () Source
NFData CPtrdiff Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CPtrdiff -> () Source
NFData CSChar Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CSChar -> () Source
NFData CSUSeconds Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CSUSeconds -> () Source
NFData CShort Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CShort -> () Source
NFData CSigAtomic Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CSigAtomic -> () Source
NFData CSize Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CSize -> () Source
NFData CTime Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CTime -> () Source
NFData CUChar Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CUChar -> () Source
NFData CUInt Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CUInt -> () Source
NFData CUIntMax Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CUIntMax -> () Source
NFData CUIntPtr Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CUIntPtr -> () Source
NFData CULLong Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CULLong -> () Source
NFData CULong Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CULong -> () Source
NFData CUSeconds Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CUSeconds -> () Source
NFData CUShort Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CUShort -> () Source
NFData CWchar Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: CWchar -> () Source
NFData ThreadId Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: ThreadId -> () Source
NFData Fingerprint Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Fingerprint -> () Source
NFData MaskingState Source	Since: deepseq-1.4.4.0
Instance details Defined in Control.DeepSeq Methods rnf :: MaskingState -> () Source
NFData ExitCode Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: ExitCode -> () Source
NFData Int16 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Int16 -> () Source
NFData Int32 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Int32 -> () Source
NFData Int64 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Int64 -> () Source
NFData Int8 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Int8 -> () Source
NFData CallStack Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: CallStack -> () Source
NFData SrcLoc Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: SrcLoc -> () Source
NFData Word16 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Word16 -> () Source
NFData Word32 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Word32 -> () Source
NFData Word64 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Word64 -> () Source
NFData Word8 Source
Instance details Defined in Control.DeepSeq Methods rnf :: Word8 -> () Source
NFData Ordering Source
Instance details Defined in Control.DeepSeq Methods rnf :: Ordering -> () Source
NFData TyCon Source	NOTE: Prior to `deepseq-1.4.4.0` this instance was only defined for `base-4.8.0.0` and later. Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: TyCon -> () Source
NFData Integer Source
Instance details Defined in Control.DeepSeq Methods rnf :: Integer -> () Source
NFData Natural Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Natural -> () Source
NFData () Source
Instance details Defined in Control.DeepSeq Methods rnf :: () -> () Source
NFData Bool Source
Instance details Defined in Control.DeepSeq Methods rnf :: Bool -> () Source
NFData Char Source
Instance details Defined in Control.DeepSeq Methods rnf :: Char -> () Source
NFData Double Source
Instance details Defined in Control.DeepSeq Methods rnf :: Double -> () Source
NFData Float Source
Instance details Defined in Control.DeepSeq Methods rnf :: Float -> () Source
NFData Int Source
Instance details Defined in Control.DeepSeq Methods rnf :: Int -> () Source
NFData Word Source
Instance details Defined in Control.DeepSeq Methods rnf :: Word -> () Source
NFData a => NFData (ZipList a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: ZipList a -> () Source
NFData (MutableByteArray s) Source	Since: deepseq-1.4.8.0
Instance details Defined in Control.DeepSeq Methods rnf :: MutableByteArray s -> () Source
NFData a => NFData (Complex a) Source
Instance details Defined in Control.DeepSeq Methods rnf :: Complex a -> () Source
NFData a => NFData (Identity a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Identity a -> () Source
NFData a => NFData (First a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: First a -> () Source
NFData a => NFData (Last a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Last a -> () Source
NFData a => NFData (Down a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Down a -> () Source
NFData a => NFData (First a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: First a -> () Source
NFData a => NFData (Last a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: Last a -> () Source
NFData a => NFData (Max a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: Max a -> () Source
NFData a => NFData (Min a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: Min a -> () Source
NFData m => NFData (WrappedMonoid m) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: WrappedMonoid m -> () Source
NFData a => NFData (Dual a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Dual a -> () Source
NFData a => NFData (Product a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Product a -> () Source
NFData a => NFData (Sum a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Sum a -> () Source
NFData (IORef a) Source	NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: IORef a -> () Source
NFData (MVar a) Source	NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: MVar a -> () Source
NFData (FunPtr a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: FunPtr a -> () Source
NFData (Ptr a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: Ptr a -> () Source
NFData a => NFData (Ratio a) Source
Instance details Defined in Control.DeepSeq Methods rnf :: Ratio a -> () Source
NFData (StableName a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: StableName a -> () Source
NFData a => NFData (NonEmpty a) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: NonEmpty a -> () Source
NFData a => NFData (Maybe a) Source
Instance details Defined in Control.DeepSeq Methods rnf :: Maybe a -> () Source
NFData a => NFData (a) Source	Since: deepseq-1.4.6.0
Instance details Defined in Control.DeepSeq Methods rnf :: (a) -> () Source
NFData a => NFData [a] Source
Instance details Defined in Control.DeepSeq Methods rnf :: [a] -> () Source
(NFData a, NFData b) => NFData (Either a b) Source
Instance details Defined in Control.DeepSeq Methods rnf :: Either a b -> () Source
NFData (Fixed a) Source	Since: deepseq-1.3.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Fixed a -> () Source
NFData (Proxy a) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Proxy a -> () Source
(NFData a, NFData b) => NFData (Arg a b) Source	Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: Arg a b -> () Source
(NFData a, NFData b) => NFData (Array a b) Source
Instance details Defined in Control.DeepSeq Methods rnf :: Array a b -> () Source
NFData (STRef s a) Source	NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: STRef s a -> () Source
NFData (a -> b) Source	This instance is for convenience and consistency with `seq`. This assumes that WHNF is equivalent to NF for functions. Since: deepseq-1.3.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: (a -> b) -> () Source
(NFData a, NFData b) => NFData (a, b) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a, b) -> () Source
NFData a => NFData (Const a b) Source	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Const a b -> () Source
NFData (a :~: b) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods rnf :: (a :~: b) -> () Source
(NFData a1, NFData a2, NFData a3) => NFData (a1, a2, a3) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3) -> () Source
(NFData1 f, NFData1 g, NFData a) => NFData (Product f g a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods rnf :: Product f g a -> () Source
(NFData1 f, NFData1 g, NFData a) => NFData (Sum f g a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods rnf :: Sum f g a -> () Source
NFData (a :~~: b) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods rnf :: (a :~~: b) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4) => NFData (a1, a2, a3, a4) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3, a4) -> () Source
(NFData1 f, NFData1 g, NFData a) => NFData (Compose f g a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods rnf :: Compose f g a -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) => NFData (a1, a2, a3, a4, a5) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3, a4, a5) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) => NFData (a1, a2, a3, a4, a5, a6) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3, a4, a5, a6) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) => NFData (a1, a2, a3, a4, a5, a6, a7) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3, a4, a5, a6, a7) -> () Source
(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) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3, a4, a5, a6, a7, a8) -> () Source
(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) Source
Instance details Defined in Control.DeepSeq Methods rnf :: (a1, a2, a3, a4, a5, a6, a7, a8, a9) -> () Source

Helper functions

deepseq :: NFData a => a -> b -> b infixr 0 Source

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: deepseq-1.1.0.0

force :: NFData a => a -> a Source

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 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: deepseq-1.2.0.0

($!!) :: NFData a => (a -> b) -> a -> b infixr 0 Source

the deep analogue of $!. In the expression f $!! x, x is fully evaluated before the function f is applied to it.

Since: deepseq-1.2.0.0

(<$!!>) :: (Monad m, NFData b) => (a -> b) -> m a -> m b infixl 4 Source

Deeply strict version of <$>.

Since: deepseq-1.4.3.0

rwhnf :: a -> () Source

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: deepseq-1.4.3.0

Liftings of the NFData class

For unary constructors

class NFData1 f where Source

A class of functors that can be fully evaluated.

Since: deepseq-1.4.3.0

Minimal complete definition

Nothing

Methods

liftRnf :: (a -> ()) -> f a -> () Source

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.

default liftRnf :: (Generic1 f, GNFData One (Rep1 f)) => (a -> ()) -> f a -> () Source

Instances

Instances details

NFData1 ZipList Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> ZipList a -> () Source
NFData1 Identity Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Identity a -> () Source
NFData1 First Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> First a -> () Source
NFData1 Last Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Last a -> () Source
NFData1 Down Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Down a -> () Source
NFData1 First Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> First a -> () Source
NFData1 Last Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Last a -> () Source
NFData1 Max Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Max a -> () Source
NFData1 Min Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Min a -> () Source
NFData1 WrappedMonoid Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> WrappedMonoid a -> () Source
NFData1 Dual Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Dual a -> () Source
NFData1 Product Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Product a -> () Source
NFData1 Sum Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Sum a -> () Source
NFData1 IORef Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> IORef a -> () Source
NFData1 MVar Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> MVar a -> () Source
NFData1 FunPtr Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> FunPtr a -> () Source
NFData1 Ptr Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Ptr a -> () Source
NFData1 Ratio Source	Available on `base >=4.9` Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Ratio a -> () Source
NFData1 StableName Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> StableName a -> () Source
NFData1 NonEmpty Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> NonEmpty a -> () Source
NFData1 Maybe Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Maybe a -> () Source
NFData1 Solo Source	Since: deepseq-1.4.6.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Solo a -> () Source
NFData1 [] Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> [a] -> () Source
NFData a => NFData1 (Either a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> Either a a0 -> () Source
NFData1 (Fixed :: Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Fixed a -> () Source
NFData1 (Proxy :: Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Proxy a -> () Source
NFData a => NFData1 (Arg a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> Arg a a0 -> () Source
NFData a => NFData1 (Array a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> Array a a0 -> () Source
NFData1 (STRef s) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> STRef s a -> () Source
NFData a => NFData1 ((,) a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> (a, a0) -> () Source
NFData a => NFData1 (Const a :: Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> Const a a0 -> () Source
NFData1 ((:~:) a) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> (a :~: a0) -> () Source
(NFData a1, NFData a2) => NFData1 ((,,) a1 a2) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a) -> () Source
(NFData1 f, NFData1 g) => NFData1 (Product f g) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Product f g a -> () Source
(NFData1 f, NFData1 g) => NFData1 (Sum f g) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Sum f g a -> () Source
NFData1 ((:~~:) a :: Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> (a :~~: a0) -> () Source
(NFData a1, NFData a2, NFData a3) => NFData1 ((,,,) a1 a2 a3) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a3, a) -> () Source
(NFData1 f, NFData1 g) => NFData1 (Compose f g) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> Compose f g a -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4) => NFData1 ((,,,,) a1 a2 a3 a4) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a3, a4, a) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) => NFData1 ((,,,,,) a1 a2 a3 a4 a5) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a3, a4, a5, a) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) => NFData1 ((,,,,,,) a1 a2 a3 a4 a5 a6) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a3, a4, a5, a6, a) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) => NFData1 ((,,,,,,,) a1 a2 a3 a4 a5 a6 a7) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a3, a4, a5, a6, a7, a) -> () Source
(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) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> (a1, a2, a3, a4, a5, a6, a7, a8, a) -> () Source

rnf1 :: (NFData1 f, NFData a) => f a -> () Source

Lift the standard rnf function through the type constructor.

Since: deepseq-1.4.3.0

For binary constructors

class NFData2 p where Source

A class of bifunctors that can be fully evaluated.

Since: deepseq-1.4.3.0

Methods

liftRnf2 :: (a -> ()) -> (b -> ()) -> p a b -> () Source

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.

Instances

Instances details

NFData2 Either Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Either a b -> () Source
NFData2 Arg Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Arg a b -> () Source
NFData2 Array Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Array a b -> () Source
NFData2 STRef Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> STRef a b -> () Source
NFData2 (,) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a, b) -> () Source
NFData2 (Const :: Type -> Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Const a b -> () Source
NFData2 ((:~:) :: Type -> Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a :~: b) -> () Source
NFData a1 => NFData2 ((,,) a1) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a, b) -> () Source
NFData2 ((:~~:) :: Type -> Type -> Type) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a :~~: b) -> () Source
(NFData a1, NFData a2) => NFData2 ((,,,) a1 a2) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a2, a, b) -> () Source
(NFData a1, NFData a2, NFData a3) => NFData2 ((,,,,) a1 a2 a3) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a2, a3, a, b) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4) => NFData2 ((,,,,,) a1 a2 a3 a4) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a2, a3, a4, a, b) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) => NFData2 ((,,,,,,) a1 a2 a3 a4 a5) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a2, a3, a4, a5, a, b) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) => NFData2 ((,,,,,,,) a1 a2 a3 a4 a5 a6) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a2, a3, a4, a5, a6, a, b) -> () Source
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) => NFData2 ((,,,,,,,,) a1 a2 a3 a4 a5 a6 a7) Source	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> (a1, a2, a3, a4, a5, a6, a7, a, b) -> () Source

rnf2 :: (NFData2 p, NFData a, NFData b) => p a b -> () Source

Lift the standard rnf function through the type constructor.

Since: deepseq-1.4.3.0

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/9.4.2/docs/libraries/deepseq-1.4.8.0/Control-DeepSeq.html

Control.DeepSeq

Contents

Description

NFData class

Minimal complete definition

Methods

Generic NFData deriving

Compatibility with previous deepseq versions

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`Generic` `NFData` deriving

Compatibility with previous `deepseq` versions