Re: XQuery (and XML) vs LISP

JOG wrote:
> Christopher Browne wrote:
> > > Jan Hidders wrote:
> > > I have no candidate in mind for a framework for comparing the
> > > expressive power of tree querying or tree rewriting
> > > languages. Sigh. The situation is so much clearer and cleaner with
> > > relations.
> >
> > The trouble is that relations require taking something of a "set"
> > perspective, and if facts aren't being expressed that way naturally,
> > well, down that road lies some ghastlyness :-).
>
> Given that the over the last century virtually all of mathematics
> (mereology aside) has been recontextualised in terms of the "set"
> perspective, I'd be mighty impressed if you could find a fact that
> doesn't do so naturally too.

[Note that the above quote attributed to the estimable Jan Hidders was actually said by me.]

This is a powerful and important point, and deserves much weight. But at the same time, I don't think sets + the relational algebra are enough to keep me happy. I want lists, too.

I might also note that over the last half centure, virtually all of programming
has been done with ordered data, not unordered data. Lisp and Fortran, C++ and Java, etc., all have arrays but not sets built in. Note that I'm
not saying that I think we want lists instead of sets-- we want both.

Marshall Received on Sun Feb 05 2006 - 05:12:46 CET