Rexical is a lexical scanner generator that is used with Racc to generate Ruby programs. Rexical is written in Ruby.
Several examples of Rexical grammar files are provided in the sample directory.
Here is an example of a lexical definition:
class Sample
macro
BLANK [\ \t]+
rule
{BLANK} # no action
\d+ { [:digit, text.to_i] }
\w+ { [:word, text] }
\n
. { [text, text] }
end
Here are examples of 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
The description files for lexical analysis in the sample directory are the files ending with the .rex extension.
-
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.