Re: OO foundation

Marshall wrote:

>Well, I didn't say one couldn't code up JOIN and UNION in
>an OOPL. For example in Java, Collections.addAll() as used
>in classes implementing the Set interface is UNION. We are
>approaching the edge of the Turing tarpit here.
>
>My point was that JOIN and UNION are not to be found
>in the *foundations* of OOPLs,

While my point is that they don't need to be, if they're easy to express, and that they are in most OO languages I know (but not in Java). The other point is that JOIN assumes a "helicopter" view of data that OO fundamentally doesn't assume.

-- 
Reinier