RE: [xml-dev] can you use inheritance (extension) in relax ng?

["Dare Obasanjo" <dareo@microsoft.com>]

________________________________

From: Simon St.Laurent [mailto:simonstl@simonstl.com]
Sent: Sat 10/25/2003 7:30 AM
To: xml-dev@lists.xml.org
Subject: RE: [xml-dev] can you use inheritance (extension) in relax ng?


It seems like W3C XML Schema really fails at data typing in some
important ways.

On the structure side, it tries to offer too much. Type hierarchies are
at the heart of how WXS defines structures, but those hierarchies can be
cut across by substitution groups and then differently by keys.  It
seems to combine the restrictions of single-inheritance with the
complications of multiple inheritance and then adds further
complication.  (I also don't think extension and restriction can cope
with both object structures and XML issues, though that at least is a
genuinely difficult problem.)

[Dare Obasanjo] I have an article on this very topic that should be published on XML.com next week. 

If I was interested in building type systems around XML documents, I
think I'd be even more frustrated with W3C XML Schema than I am today.

[Dare Obasanjo] You're not the only one. See  http://www.research.microsoft.com/~emeijer/Papers/XML2003/xml2003.html