regions: Provides the region monad for safely opening and working with scarce resources.

[ bsd3, control, library, monadic-regions ] [ Propose Tags ]
Versions 0.1,, 0.2, 0.3, 0.4, 0.5, 0.6,, 0.7,, 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.*) [details]
License BSD-3-Clause
Copyright 2009-2010 Bas van Dijk
Author Bas van Dijk
Maintainer Bas van Dijk <>
Category Control, Monadic Regions
Source repo head: darcs get
Uploaded by BasVanDijk at Sat Sep 11 14:17:48 UTC 2010
Distributions NixOS:0.11
Downloads 5209 total (40 in the last 30 days)
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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.




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