in reply to RFC: Set::Select: get intersection or union of sets; or more generally, the set of elements that are in one or more input sets

Sounds quite good. Yes, I think this would be useful. I don't really have good answers to the other two questions.
  • Comment on Re: RFC: Set::Select: get intersection or union of sets; or more generally, the set of elements that are in one or more input sets

In Section Meditations