Re: RFC 179 (v1) More functions from set theory to manipulate arrays

[Tom Christiansen]

Also: have you looked at what's on CPAN for handling sets?  
Here's a casual search result:

    Math::Expr::MatchSet         Set::Scalar
    Math::Expr::VarSet           Set::Scalar::Base
    ObjStore::Set                Set::Scalar::Null
    ObjStore::SetEmulation       Set::Scalar::Real
    Set::Bag                     Set::Scalar::Universe
    Set::IntRange                Set::Scalar::Valued
    Set::IntSpan                 Set::Scalar::ValuedUniverse
    Set::NestedGroups            Set::Scalar::Virtual
    Set::Object                  SetDualVar

In particular, I wonder what you think of Steffen Beyer's approaches.

--tom