• github.com/tenderlove/rexical/tree/master

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.