pvar: Mutable variable with primitive values

[ bsd3, data, library ] [ Propose Tags ]

Mutable variable PVar that is backed by a single value MutableByteArray

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Data
- Primitive
  - Data.Primitive.PVar
    - Data.Primitive.PVar.Unsafe

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pvar-1.0.0.0.tar.gz [browse] (Cabal source package)
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Versions [RSS]	0.1.0.0, 0.1.1.0, 0.2.0.0, 1.0.0.0
Change log	CHANGELOG.md
Dependencies	base (>=4.9 && <6), deepseq, primitive (>=0.7.1.0) [details]
License	BSD-3-Clause
Copyright	2020 Alexey Kuleshevich
Author	Alexey Kuleshevich
Maintainer	alexey@kuleshevi.ch
Revised	Revision 1 made by lehins at 2020-10-19T15:09:31Z
Category	Data
Home page	https://github.com/lehins/pvar#readme
Bug tracker	https://github.com/lehins/pvar/issues
Source repo	head: git clone https://github.com/lehins/pvar
Uploaded	by lehins at 2020-10-19T15:00:28Z
Distributions	LTSHaskell:1.0.0.0, NixOS:1.0.0.0, Stackage:1.0.0.0
Reverse Dependencies	1 direct, 15 indirect [details]
Downloads	3139 total (75 in the last 30 days)
Rating	2.0 (votes: 1) [estimated by Bayesian average]
Your Rating	λ λ λ
Status	Docs available [build log] Last success reported on 2020-10-19 [all 1 reports]

Readme for pvar-1.0.0.0

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pvar

Interface for a mutable variable PVar that can hold values that have Prim instance.

Status

Language	Travis	Azure	Coveralls

Package	Hackage	Nightly	LTS
`pvar`

Overview

Main features include:

Performance. There is practically no overhead when compared to operating on pure values, although there is a higher memory overhead, since PVar is backed by a MutableByteArray#
Atomic operations for PVars with Int values. This includes a unique function that is not available in ghc-prim out of the box:

atomicModifyIntPVar :: PrimMonad m => PVar m Int -> (Int -> (Int, a)) -> m a

Works in PrimMonad, therefore it is usable with ST, IO and various transformer monads.
Easy access to PVar contents with Storable
isByteArrayPinned, isMutableByteArrayPinned function that work on ghc-7.10 and ghc-8.0 as well as all the newer ones.