Changes in Alex 2.3 vs. 2.2
* monadUserState wrapper (Alain Cremieux)
* Efficient lexing of strict ByteStrings (Don Stewart)
* Works with Cabal 1.2, 1.4 & 1.6
Changes in Alex 2.2 vs. 2.1.0:
* Requires Cabal 1.2
* ByteString wrappers: use Alex to lex ByteStrings directly
Changes since 2.0.1:
* Switch to a Cabal build system: you need a recent version of Cabal
(1.1.6 or later). If you have GHC 6.4.2, then you need to upgrade
Cabal before building Alex. GHC 6.6 is fine.
* Slight change in the error semantics: the input returned on error
is before the erroneous character was read, not after. This helps
to give better error messages.
description of the tokens to be recognised in the form of regular
expressions. It is similar to the tools lex and flex for C/C++.
Alex takes a description of tokens based on regular expressions and
generates a Haskell module containing code for scanning text
efficiently. Alex is designed to be familiar to exisiting lex users,
although it does depart from lex in a number of ways.
