Rexical is a lexical scanner generator. It is written in Ruby itself, and generates Ruby program. It is designed for use with Racc.
Here is a sample lexical definition:
class Sample
macro
BLANK [\ \t]+
rule
BLANK # no action
\d+ { [:digit, text.to_i] }
\w+ { [:word, text] }
\n
. { [text, text] }
end
Here is the command line usage:
$ rex sample1.rex --stub $ ruby sample1.rex.rb sample1.c $ rex sample2.rex --stub $ ruby sample2.rex.rb sample2.bas $ racc calc3.racc $ rex calc3.rex $ ruby calc3.tab.rb
-
ruby version 1.8.x or later.
-
sudo gem install rexical
Rexical is distributed under the terms of the GNU Lesser General Public License version 2. Note that you do NOT need to follow LGPL for your own parser (Rexical outputs). You can provide those files under any licenses you want.