xml-dev - XSet, an XML Property Set, was: re: Why the Infoset?

[Jonathan Borden <jborden@mediaone.net>]

Sean McGrath wrote:

>
>
> [At 20:56 31/07/00 -0400, Jonathan Borden wrote:]
> >
> >Suppose this: we define a 100% complete abstract model of an XML 1.0, and
> >XML Namespace compliant document, and also define a mechanism
> for defining
> >subsets of such an abstract model. ... In
> >this scenario, the current XML Information Set would be derived from the
> >full fidelity  Base XML Information Set.
>
> Count me in.
>
> This is the sort of "partical physics" I think we need
> beneath XML 1.
>
There is a common thread among the Infoset, Common XML, SML etc, to define a
subset of XML 1.0 for various purposes. What we need is a mechanism to
specify the abstract XML 1.0 + Namespace model, and a way to clearly subset
this for particular purposes. In the same way that HyTime has provided
guidance for things like XLink (et al.), XSet base itself on Property Sets
and Grove Plans.

In the past it has been discussed that from the SGML Property Set, one could
develop an XML Grove Plan to define subsetting operations. Now that more
time has past, it is even more clear that while the concepts of the grove,
property sets and grove plans are still important, the particular syntax
specified in their implementation is not viable for widespread adoption.

I think the problem is that the SGML Property Set appears to have been
designed for machine, not human, consumption. What is needed is an XML
implementation, in an XML document which is designed for both Human and
Machine consumption. That is, we need to make a viable implementation both
understandable and unambiguosly correct.

In terms of the Infoset, which has been specified in RDF in an appendix,
perhaps the best way forward would be to expand John Cowan's excellent work
into a full fidelity description(RDFS?) and develop a subsetting mechanism
to specify what part of the full schema is used for Infoset, CXML etc. That
is: make Appendix D normative, not just informative.

Jonathan Borden
The Open Healthcare Group
http://www.openhealth.org