Re: XQuery (and XML) vs LISP

Jan Hidders wrote:
> Marshall Spight wrote:
> >
> > I vaguely wonder whether it would be possible to use, or adapt,
> > relational techniques for querying nested relations as an alternative
> > to either XQuery or pattern matching.

Doesn't Tutorial-D include this capability?

> I think the answer is, vaguely, yes. :-) You can think of the tree is a
> binary relation, and if you want access to all descendants the system
> could provide conceptually the transitive closure to you (so for the
> binary table R you could for example use R* as the notation for its
> transitive closure) and from there you could specify your queries as
> usual. Most XPath queries would then translatie to simple
> SELECT-FROM-WHERE queres.

If they are not nested relations but nested ordered lists, as possible with XML documents, then you would lose information this way, right? I'll admit this is flying over my head so I might not be understanding your response. Cheers! --dawn Received on Tue Feb 07 2006 - 23:30:32 CET