Name: storable-record
Version: 0.0.4
Category: Data, Foreign
Synopsis: Elegant definition of Storable instances for records
Description:
With this package
you can build a Storable instance of a record type
from Storable instances of its elements in an elegant way.
It does not do any magic,
just a bit arithmetic to compute the right offsets,
that would be otherwise done manually
or by a preprocessor like C2HS.
I cannot promise that the generated memory layout
is compatible with that of a corresponding C struct.
However, the module generates the smallest layout
that is possible with respect to the alignment of the record elements.
If you encounter, that a record does not have a compatible layout,
we should fix that.
But also without C compatibility this package is useful
e.g. in connection with StorableVector.
.
We provide Storable instance support for several cases:
.
* If you wrap a type in a @newtype@,
then you can lift its 'Storable' instance to that @newtype@
with the module "Foreign.Storable.Newtype".
This way you do not need the @GeneralizedNewtypeDeriving@ feature of GHC.
.
* If you have a type that is an instance of 'Traversable',
you can use that feature for implementation of 'Storable' methods.
The module "Foreign.Storable.Traversable"
allows manipulation of the portion of your type,
that is accessible by 'Traversable' methods.
For instance with the type
@data T a = Cons Int [a]@
and an according 'Traversable' implementation,
you can load and store the elements of the contained list.
This may be part of a 'Storable' implementation of the whole type.
.
* If you have a record containing elements of various types,
then you need module "Foreign.Storable.Record".
.
Note however that the Storable instances
defined with this package are quite slow in (up to) GHC-6.12.1.
I'm afraid this is due to incomplete inlining,
but we have still to investigate the problem.
.
For examples see packages @storable-tuple@ and @sample-frame@.
License: BSD3
License-file: LICENSE
Author: Henning Thielemann <storable@henning-thielemann.de>
Maintainer: Henning Thielemann <storable@henning-thielemann.de>
Homepage: http://code.haskell.org/~thielema/storable-record/
Stability: Experimental
Build-Type: Simple
Tested-With: GHC==6.8.2, GHC==6.10.4, GHC==6.12.1, GHC==8.0.1
Cabal-Version: >=1.6
Source-Repository head
Type: darcs
Location: http://code.haskell.org/~thielema/storable-record/
Source-Repository this
Type: darcs
Location: http://code.haskell.org/~thielema/storable-record/
Tag: 0.0.4
Flag splitBase
description: Choose the new smaller, split-up base package.
Flag buildTests
description: Build speed test
default: False
Library
Build-Depends:
transformers >=0.2 && <0.6,
semigroups >=0.1 && <1.0,
utility-ht >=0.0.1 && <0.1
If flag(splitBase)
Build-Depends:
base >= 3 && < 6
Else
Build-Depends:
special-functors >= 1.0 && <1.1,
base >= 1.0 && < 2
GHC-Options: -Wall
Hs-Source-Dirs: src
Exposed-Modules:
Foreign.Storable.Record
Foreign.Storable.Newtype
Foreign.Storable.Traversable
Foreign.Storable.FixedArray
Other-Modules:
Foreign.Storable.RecordMinimalSize
Foreign.Storable.RecordReaderPtr
Foreign.Storable.TraversableUnequalSizes
Executable storable-record-speed
If flag(buildTests)
Build-Depends:
storablevector >=0.2.7 && <0.3,
timeit >=1.0 && <1.1
Else
Buildable: False
GHC-Options: -Wall
Hs-Source-Dirs: src
Main-Is: SpeedTest.hs