in reply to
Re: Relationships of Matching Sets
in thread Relationships of Matching Sets
Great idea, this was the first module that came to my mind. Also, if you'd like to explore your ideas on "close matching," try subclassing Set::Scalar. It seems like it might be difficult to define a general solution for "almost matching" in terms of sets but you could certainly implement specific solutions easily by adding the methods you want to a subclass of Set::Scalar (and leave the union, symmetric_difference, etc. in the original class definition).
Best of luck. :)