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What do you mean by "schemas corresponding to object frameworks"? If you mean schemas generated from classes in an OO language they definitely would be much simpler than schemas designed for validating document-centric XML by humans. A serialized object state is basically a complex type containing a sequence of simple types and/or nested complex types of the same form. All you need is DTDs + simple types (e.g. Microsoft's XDR) and you'd have hit the 80% of the usage requirements for generating schemas from classes.
The complexity in XSD-based object<->XML frameworks (which has caused much consternation in the XML Web Services world) is the fact that one has to map the additional complexity of XML schema to OO constructs when no such concepts exist in the OO world.
PITHY WORDS OF WISDOM
If you don't change your direction, you may end up where you were headed.
From: Bullard, Claude L (Len) [mailto:email@example.com]
Sent: Mon 10/18/2004 8:30 AM
To: 'Michael Kay'; 'Michael Champion'; 'firstname.lastname@example.org'
Subject: RE: [xml-dev] Getting specs/standards right (was UPA and schema handling)
It might be interesting to compare schemas corresponding
to object frameworks for a complexity measurement comparison
to 'documents' if there is some definition for document
that enables one to classify one on sight.
Ontologies always come down to a test.
From: Michael Kay [mailto:email@example.com]
> Once again, what is a critical use case in the "data" world is an
> annoying hinderance to getting work done in the 'document ' world :-)
> (and vice-versa, I'm not taking sides!).
Actually, it's quite useful to be able to write an XSLT template rule that
matches all "inline" elements; the more complex and extensible your schema
becomes, the more useful this is; and the most complex schemas I have seen
are in the "document" world.
Doing this relies on associating types with elements. I think the notion
that types are useful only in the "data" world is misguided. In fact, XSLT
1.0 patterns can be seen as an attempt at typing that provides a subset of
the information you can get from schema processing, but leaves it entirely
to the programmer to maintain consistency between the schema and stylesheet,
which becomes more and more laborious as the schema grows.
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