Re: Reminder, blatant ad

Marshall Spight wrote:
> dawn wrote:
> > x wrote:
> > >
> > > > > What are the basic operations for combining lists and sets ?
> > >
> > > > The ones that come with any general purpose programming language.
> > > Can you make a list or a set with them and post it ?
> >
> > That would take a smarter man than I. I'd be fine with the java.lang
> > libraries. They are well documented. ;-)
>
> (You probably meant java.util; specifically the "Collections API.")

My thinking was muddled right then, I suspect, but I started with the collections api and did have java.util but before sending it figured I only needed the basic language and could build up from there. But, yes, I was initially thinking of the collections api.

>
> The collections API is quite an achievement, and is IMHO a significant
> contributor to Java's overall success. But it doesn't qualify
> as a foundational set of operations. It's goal is maximal inclusiveness
> and convenience; not minimal completeness.

Yes, it is very useful. Someone once mentioned that it does not have relations. However, with maps, which are functions, you could implement any relation that is a function (any with a primary key). It just doesn't have the same operations on that map as on relations in an rdbms.

> I think a good case can be made for the basic operations on set
> being the union, intersection, difference; for relations being the
> relational algebra, and for lists being simply car, cdr, cons.
> How you would combine operations on lists and sets is an
> open question in my mind. Can natural join be applied to
> a pair of lists?
>
>
> > > Why not asking for a model to support all mathematics ?
> >
> > Again, I'm good with programming languages and libraries thereof.
>
> Ha! How are these different?

That was somewhat my point. It is the RM that insists on restricting the mathematics to some castrated subset of mathematics that causes problems for the user, methinks.

> Riddle: I want a way to express
> all computable functions. Am I a mathematician or a programmer?

Yes. smiles. --dawn
>
> Marshall
Received on Mon Feb 06 2006 - 01:28:46 CET