The regions package
This package provides the region monad transformer. Scarce resources like files, memory pointers or USB devices for example can be opened in a region. When the region terminates, all opened resources will be automatically closed. The main advantage of regions is that the opened resources can not be returned from the region which ensures no I/O with closed resources is possible.
The primary technique used in this package is called "Lightweight monadic regions" which was invented by Oleg Kiselyov and Chung-chieh Shan. See:
Also see the regions-monadsfd and regions-monadstf packages which provide instances for the classes in the respected monads packages.
For an example on how to use this library see the safer-file-handles, usb-safe or regional-pointers packages.
Note that if you want to open your type of scarce resource in a region, the only thing you have to do is define an instance for the Resource class (which you can find in: Control.Resource).
|Versions||0.1, 0.1.0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.6.0.1, 0.7, 0.7.0.1, 0.8, 0.8.1, 0.9, 0.10, 0.11|
|Dependencies||base (≥4 & <4.3), base-unicode-symbols (≥0.1.1 & <0.3), MonadCatchIO-transformers (0.2.*), transformers (0.2.*)|
|Copyright||2010 Bas van Dijk|
|Author||Bas van Dijk|
|Maintainer||Bas van Dijk <firstname.lastname@example.org>|
|Category||Control, Monadic Regions|
|Source repository||darcs get http://code.haskell.org/~basvandijk/code/regions|
|Upload date||Sun May 2 20:24:19 UTC 2010|