Current stable version is
released at Jan 21, 2014
[2014-01-21] It's been a long time coming: JFlex 1.5 is out! See below for release notes.
[2009-01-31] JFlex 1.4.3 released.
[2008-05-27] JFlex 1.4.2 released.
There now exists a
JFlex Maven plugin, contributed by Régis Décamps.
It integrates JFlex into the Maven
software project management tool.
What is it?
JFlex is a lexical analyzer generator (also known as scanner generator)
for Java(tm), written in Java(tm).
It is also a rewrite of the very useful tool JLex
which was developed by Elliot Berk at Princeton University. As Vern Paxson
states for his C/C++ tool flex: They do not share any code though.
JFlex is designed to work together with the LALR parser generator
CUP by Scott Hudson, and
the Java modification of Berkeley Yacc BYacc/J by Bob Jamison.
It can also be used together with other parser generators like ANTLR or as a standalone tool.
Features of JFlex.
Is it free?
Yes. It is released under a permissive open-source BSD-style license and available for
free download. See also Copyright, License & Warranty.
What's new in version 1.5?
Version 1.5 is the first new major release in a few years.
The most important changes are
- JFlex now conforms with Unicode Regular
Expressions UTS#18 Basic Unicode Support - Level 1. Supplementary code
points (above the Basic Multilingual Plane) are not yet supported. Huge
thanks to Steve Rowe for his extensive work on this!
- Support for new meta characters \s, \S, \d, \D, \w, \W, nested character sets and new character set operations (union, intersection, set difference, symmetric difference).
- The "." meta character now stands for all non-newline characters. Old behaviour available with the --legacydot option.
- New \R meta character stands for all newline characters.
- Moved to a more permissive BSD-style license.
- JFlex now needs at least JDK 1.5 to run.
- Changed the build from Ant to Maven.
- Updated JFlex to CUP version 0.11a.
- Fixed outstanding bugs.
See also the change log file for the
complete list of changes.
What's new on these pages?
There is a list of files on this website ordered by modification date.
What platforms does JFlex support?
JFlex should run on any platform that supports a JRE/JDK 1.5 or above.
Java is a
trademark of Sun Microsystems. JFlex
is not sponsored by or affiliated with Sun Microsystems