I already have a very basic verilog parser (gem) written in ruby called verilog, if you could consider contributing to that instead, or it might give an idea of how to start.
I also have a gem called rubyit, which is command line utility to parse files with erb and generate the standard version of the file. Which can be used for extendable verilog templates, similar to generate statements but gives a flexible port list and ability to check the generated code.