regexp_parser is a Ruby gem for tokenizing, parsing, and transforming
regular expressions.

Features:

* Multilayered
  * A scanner/tokenizer based on Ragel
  * A lexer that produces a "stream" of token objects.
  * A parser that produces a "tree" of Expression objects (OO API)
* Recognizes Ruby 1.8, 1.9, and 2.x regular expressions