This task is to add syntax highlighting to Haiku's Pe (programmer's editor).  There was a similar task to add support for XML files: http://www.google-melange.com/gci/task/view/google/gci2012/7978202

For this task you should research Ruby's code syntax so that you can apply the highlighting in a correct way.  You can probably start with the code from the C++ highlighter and extend from there to fit Ruby's syntax.

http://developer.berlios.de/projects/pe-editor