alex: Alex is a tool for generating lexical analysers in Haskell

[ bsd3, development, program ] [ Propose Tags ]
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, 3.2.2, 3.2.3
Change log
Dependencies array, base (>=1.0 && <5), containers, directory, QuickCheck (>=2) [details]
License BSD-3-Clause
Copyright (c) Chis Dornan, Simon Marlow
Author Chris Dornan and Simon Marlow
Maintainer Simon Marlow <>
Category Development
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Source repo head: git clone
Uploaded by SimonMarlow at Sat Sep 2 09:40:13 UTC 2017
Distributions Arch:3.2.3, Debian:3.1.6, Fedora:3.2.3, FreeBSD:3.1.4, LTSHaskell:3.2.3, NixOS:3.2.3, Stackage:3.2.3, openSUSE:3.2.3
Executables alex
Downloads 103228 total (359 in the last 30 days)
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Status Docs not available [build log]
Last success reported on 2017-09-02 [all 3 reports]
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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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Readme for alex-3.2.2

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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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