At this point, these are completely new classes. I'm trying to build a UI prototype (Win32::GUI), and simultaneously keep the interface to my search as flexible as possible for two reasons:

1. I don't know yet whether that search will be running on a local database, a local filesystem, or some kind of RPC call.

2. I'm fully expecting the customer to say "we want it to run on linux too"

I've also now hit upon the idea of passing the search method as a coderef. Does anyone have any comments on that approach?