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I've really been careless with my attributions lately. I'll try to do better.
Alaric B. Snell:
> > More generally, the more you rely on the "data types"
> > (very broadly defined) to define and process the XML, the less useful it
> > will be for
> > anyone who doesn't use the same semantics, type sytstems, language
> > bindings,
> > etc. as you do.
> I don't think so. Adding more restrictive typing doesn't change the data in
> the documents,
False. Data typing most certainly changes the data in the document. This is
not automatically a bad thing.
> it just makes automated processing easier.
Debatable. But even if granted, the point is that the automation is almost
invariably misguided because, as I've said many times, the data types people
use very rarely have correspondence to their real-world analogues. And the
carelessness that strong typing tends to encourage is a very common cause of
integration and maintenance problems.
> Instead of allowing
> a date field to contain "yesterday", "my birthday", "1/2/2002" (note the
> ambiguity; 1st feb or 2nd jan) and so on you restrict it to a specific date
> type written "YYYY-MM-DD", and the increased rigidity makes it possible to
> write code that can be shown to handle all the cases.
This can be done without static typing. A generic constraint system does the
job as well, and allows the developer to define constraints that approximate
the real world. Proof of correctness does *not* require static typing, if
that's what you're driving at here.
In any case, you seem to miss the point. As I said to Norm:
I have no problem with data typing qua data types. I do object to
* The bias towards static types
* The lack of modularity in W3C efforts to incorporate data typing into XML
Uche Ogbuji Fourthought, Inc.
http://uche.ogbuji.net http://4Suite.org http://fourthought.com
Tour of 4Suite - http://www.xml.com/pub/a/2002/10/16/py-xml.html
Proper XML Output in Python - http://www.xml.com/pub/a/2002/11/13/py-xml.html
RSS for Python - http://www-106.ibm.com/developerworks/webservices/library/ws-p
Debug XSLT on the fly - http://www-106.ibm.com/developerworks/xml/library/x-deb