deepseq-1.1.0.1: Fully evaluate data structures

Portabilityportable
Stabilitystable
Maintainerlibraries@haskell.org

Control.DeepSeq

Description

Provides an overloaded function deepseq for fully evaluating data structures.

Synopsis

Documentation

deepseq :: NFData a => a -> b -> bSource

Fully evaluates its argument. 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.

class NFData a whereSource

Methods

rnf :: a -> ()Source

rnf should reduce its argument to normal form (that is, fully evaluate all sub-components), and then return '()'.

The default implementation of rnf is

 rnf a = a `seq` ()

which may be convenient when defining instances for data types with no unevaluated fields (e.g. enumerations).

Instances

NFData Bool 
NFData Char 
NFData Double 
NFData Float 
NFData Int 
NFData Int8 
NFData Int16 
NFData Int32 
NFData Int64 
NFData Integer 
NFData Word 
NFData Word8 
NFData Word16 
NFData Word32 
NFData Word64 
NFData () 
NFData IntSet 
NFData a => NFData [a] 
(Integral a, NFData a) => NFData (Ratio a) 
(RealFloat a, NFData a) => NFData (Complex a) 
NFData a => NFData (Maybe a) 
NFData a => NFData (Tree a) 
NFData a => NFData (IntMap a) 
NFData a => NFData (Set a) 
(NFData a, NFData b) => NFData (Either a b) 
(NFData a, NFData b) => NFData (a, b) 
(Ix a, NFData a, NFData b) => NFData (Array a b) 
(NFData k, NFData a) => NFData (Map k a) 
(NFData a, NFData b, NFData c) => NFData (a, b, c) 
(NFData a, NFData b, NFData c, NFData d) => NFData (a, b, c, d) 
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) => NFData (a1, a2, a3, a4, a5) 
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) => NFData (a1, a2, a3, a4, a5, a6) 
(NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) => NFData (a1, a2, a3, a4, a5, a6, a7) 
(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) 
(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)