Projects / JFlex


JFlex is a flex-like lexer generator for Java with emphasis on speed and full Unicode support. It works as a standalone tool or together with the LALR parser generators CUP and BYacc/J. JFlex has support for some not so usual features like negation in regular expressions and nested input streams. It can also read JLex specifications unchanged.

Operating Systems

Recent releases

  •  28 May 2008 14:53

    Release Notes: This release fixes all known bugs of previous JFlex versions and adds support for Java generics.

    •  17 Apr 2004 06:59

      Release Notes: This release included a new, very fast minimization algorithm, a new --jlex option for strict compatibility to JLex, support for even larger scanners (up to 64K DFA states), faster character classes, a new %apiprivate switch that causes all generated and skeleton methods to be made private, and user defined javadoc class comments. %eofclose isnow turned off if it was previously turned on (e.g. by %cup). A number of internal enhancements were made and rigorous testing was performed.

      •  08 Oct 2001 20:02

        Release Notes: Fixes for all bugs reported in version 1.3.4, a vim syntax file, and out-of-the-box JDK 1.1 support again.

        •  01 Oct 2001 14:50

          Release Notes: All bugs reported for version 1.3.3 have been fixed. The requested feature of exclusive start states has been implemented. %s and %x shorthands for state declarations were introduced.

          •  22 Sep 2001 05:36

            Release Notes: Bugfixes and numerous small enhancements to the generator, runtime scanning engine, specification language, and documentation.


            Project Spotlight


            A Fluent OpenStack client API for Java.


            Project Spotlight

            TurnKey TWiki Appliance

            A TWiki appliance that is easy to use and lightweight.