Re: Reminder, blatant ad

Jan Hidders wrote:
> Marshall Spight wrote:
> >
> > Uh, well I knew you had a strong interest in XQuery. But I guess I
> > don't entirely understand your last comment; perhaps because I don't
> > know much about XQuery. It seems like, being XML based, it wouldn't
> > be altogether clear on how it feels about types and order and so
> > forth.
>
> It's extremely clear on that. XML is an ordered data model so XQuery
> deals with that extensively. XML has an elaborate typing theory
> associated with it (see XML Schema) and XQuery allows you to use that if
> you so desire.

I thought I remembered you saying to me once that attributes were unordered and element were ordered. (Or was it the other way around?) But that confuses me; since elements can be nested but attributes can't,
this seems to say that you can have nested ordered data but not nested unordered data. Why? One sign of good design I look for is orthogonality. Anyway I still haven't heard any clear indication of when or why one would use elements vs. attributes. They seem to have substantial overlap.

Is XML Schema supposed to replace DTDs? The idea of the type system and schema being separate and optional relative to the data format is incomprehensible; I cannot distinguish between an optional type system and no type system.

(The FP community has as meme that says that retrofitting a type system onto a programming language is hard, bordering on doomed; that would seem to apply here.)

I am still at a loss to explain the attraction of XML-family standards to impressive people such as yourself and Philip Wadler. My only working hypothesis is that it's the same reason that Sherlock Holmes took cocaine. Even thought it's really unhealthy, there's just not enough going on to keep the powerful mind occupied otherwise. I note that Wadler has done a lot with XML but still says "The problem that it solves isn't very hard, and it doesn't solve it very well." This would seem to fit my working hypothesis.

But I still wonder what all the fuss is about, and can't help but feel that my strong negative aesthetic reaction to XML is keeping me from seeing something otherwise valuable. I would certainly love to see a set, or even one, of an example of something short but impressive one can do with XML, so that I can be impressed the way I was impressed the first time I was when someone showed me a many-to-many association.

Marshall Received on Thu Feb 09 2006 - 02:17:09 CET