The alex package

[Tags:bsd3, program, test]

Alex is a tool for generating lexical analysers in Haskell. It takes a description of tokens based on regular expressions and generates a Haskell module containing code for scanning text efficiently. It is similar to the tool lex or flex for C/C++.

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Versions 2.1.0, 2.2, 2.3, 2.3.1, 2.3.2, 2.3.3, 2.3.4, 2.3.5, 3.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5, 3.1.0, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.1.5, 3.1.6, 3.1.7, 3.2.0, 3.2.1
Change log
Dependencies array, base (>=1.0 && <5), containers, directory, QuickCheck (>=2) [details]
License BSD3
Copyright (c) Chis Dornan, Simon Marlow
Author Chris Dornan and Simon Marlow
Maintainer Simon Marlow <>
Stability stable
Category Development
Home page
Bug tracker
Source repository head: git clone
Uploaded Tue Oct 18 10:30:04 UTC 2016 by SimonMarlow
Distributions Arch:3.2.1, Debian:3.1.6, Fedora:3.1.7, FreeBSD:3.1.4, LTSHaskell:3.1.7, NixOS:3.2.1, Stackage:3.2.1, Tumbleweed:3.1.7
Downloads 74746 total (107 in the last 30 days)
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Status Docs pending
Build status unknown [no reports yet]


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Maintainer's Corner

For package maintainers and hackage trustees

Readme for alex

Readme for alex-3.2.1

Alex: A Lexical Analyser Generator

Build Status

Alex is a Lex-like tool for generating Haskell scanners. For complete documentation, see the doc directory.

Alex is built using Cabal. First install GHC and cabal-install, then:

$ cabal configure
$ cabal build
$ cabal install

Alex version 2.0 has changed fairly considerably since version 1.x, and the syntax is almost completely different. For a detailed list of changes, see the release notes in the documentation.

Alex is now covered by a BSD-Style licence; see the licence file in the 'doc' directory for details.

The sources are in the 'src' directory and the documentation in the 'doc' directory; various examples are in the 'examples' subdirectory.

The source code in the 'src' and 'examples' directories is intended for a Haskell 98 compiler with hierarchical modules. It should work with GHC >= 5.04.

Please report any bugs or comments at

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