I never got around to rewriting it because it was too depressing, and it was only for a fun project/feature anyway ... nothing critical.
Well, I started rewriting it... at least the docs:
Set::Symbolic - base class for sets which can be operated on symbolicallyThat's as far as I've gotten. I don't think anything exists on CPAN to do this? I looked around again just now but couldn't find anything. Anybody know?
Set::Symbolic lets you define and work with sets which be manipulated and operated on symbolically. For instance, you can do operations like union, intersection, removal, etc of large or abstract sets without actually evaluating or loading their contents. When finally wanting to know the contents of a expression involving a lot of sets, Set::Symbolic will figure out the best execution plan (order of evaluation) and/or symbolic reductions to minimize loading cost of constituent sets, using hints provided by the sets themselves (which may not even know their exact size or contents).