There is the AI::Gene::Sequence (which also comes with AI::Gene::Simple) which provides a framework for storing, checking and mutating sequences of tokens. This is set up as a base class so that it can be well mapped onto any "problem" set by inheriting the mutation methods while providing your own set of fitness, creation and output methods.

I'll come clean and admit that I wrote it, but it is there, you can find my email from within the module and I'd be glad to hear from you.