pseq -deepseq

pseq :: a -> b -> b
base GHC.Conc.Sync, base GHC.Conc
pseq :: a -> b -> b
parallel Control.Parallel
Semantically identical to seq, but with a subtle operational difference: seq is strict in both its arguments, so the compiler may, for example, rearrange a `seq` b into b `seq` a `seq` b. This is normally no problem when using seq to express strictness, but it can be a problem when annotating code for parallelism, because we need more control over the order of evaluation; we may want to evaluate a before b, because we know that b has already been sparked in parallel with par. This is why we have pseq. In contrast to seq, pseq is only strict in its first argument (as far as the compiler is concerned), which restricts the transformations that the compiler can do, and ensures that the user can retain control of the evaluation order.
package containers-deepseq
package
package deepseq
package
This package provides methods for fully evaluating data structures (&quot;deep evaluation&quot;). Deep evaluation is often used for adding strictness to a program, e.g. in order to force pending exceptions, remove space leaks, or force lazy I/O to happen. It is also useful in parallel programs, to ensure pending work does not migrate to the wrong thread. The primary use of this package is via the deepseq function, a &quot;deep&quot; version of seq. It is implemented on top of an NFData typeclass (&quot;Normal Form Data&quot;, data structures with no unevaluated components) which defines strategies for fully evaluating different data types. If you want to automatically derive NFData instances via the GHC.Generics facility, there is a companion package <http:hackage.haskell.orgpackagedeepseq-generics deepseq-generics> which builds on top of this package. Version 1.3.0.2
package deepseq-generics
package
This package provides a GHC.Generics-based Control.DeepSeq.Generics.genericRnf function which can be used for providing a rnf implementation. See the documentation for the genericRnf function in the Control.DeepSeq.Generics module to get started. The original idea was pioneered in the generic-deepseq package (see http://www.haskell.org/pipermail/haskell-cafe/2012-February/099551.html for more information). This package differs from the generic-deepseq package by working in combination with the existing deepseq package as opposed to defining a conflicting drop-in replacement for deepseq's Control.Deepseq module. Version 0.1.1.1
package deepseq-th
package
This package provides a Template Haskell based mechanism for deriving optimised NFData instances for custom data types. See documentation in Control.DeepSeq.TH for more information. See also the deepseq-generics package (http://hackage.haskell.org/package/deepseq-generics) for a less experimental approach. Version 0.1.0.4
package generic-deepseq
package
This package provides a deepseq function analogous to seq, except that it traverses the entire data structure, evaluating it fully, and not just up to head normal form. Using lists as an example: > > [1,2,undefined] `seq` 3 > 3 Whereas with deepseq: > > [1,2,undefined] `deepseq` 3 > *** Exception: Prelude.undefined Unlike the deepseq package, this implementation is based on the GHC.Generics framework as found in GHC >= 7.2, so that it can generate instances automatically for any datatype that has a Generic instance, without further code. > data MyType = MyType String Int (Maybe Double) > deriving Generic > instance DeepSeq MyType Changes in version 2.0.0.0: * Vastly improved performance. As a consequence of these changes, the member function of the DeepSeq class is now rnf, instead of deepseq. * New instances for functions, Ratio and Complex types. Changes in version 2.0.1.0: * Fix the U1 and V1 instances. Changes in version 2.0.1.1: * No functional changes, updated to correct the URLs of the repository and the issue tracker. Version 2.0.1.1
rdeepseq :: NFData a => Strategy a
parallel Control.Parallel.Strategies
rdeepseq fully evaluates its argument. > rdeepseq == evalSeq Control.Seq.rdeepseq
rdeepseq :: NFData a => Strategy a
parallel Control.Seq
rdeepseq fully evaluates its argument. Relies on class NFData from module Control.DeepSeq.