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

[Tom Christiansen]

>Next, what subset of the set-theory should be implemented.  Obviously you
>refer to the basic and / or / xor, but in real practice, the other operators
>can be very useful.  Chaining operators (especially with array-based-sets)
>can be a performance nightmare.

Unless you use bitwise operators on bit vectors!  Which, on rare occasion,
I have certainly used.  It is unbelievably fast and unbelievably compact.
I think that there are modules that do this sort of thing.

The listwise union/intersection/symmetric difference code in the 
Ram uses hashes for all this, though.

--tom