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LC-51 Can XML Schema describe XSLT?

From: Martin Gudgin <marting@develop.com>
Date: Sun, 8 Oct 2000 19:24:52 +0100
Message-ID: <02ed01c03155$0e2327a0$0300a8c0@arbitrary>
To: "Schema Comments" <www-xml-schema-comments@w3.org>
Dear Mr Arnold,

The W3C XML Schema Working Group has spent the last several months
working through the comments received from the public on the last-call
draft of the XML Schema specification.  We thank you for the comments
you made on our specification during our last-call comment period, and
want to make sure you know that all comments received during the
last-call comment period have been recorded in our last-call issues
list (http://www.w3.org/2000/05/12-xmlschema-lcissues).

Among other issues, you raised the point registered as issue LC-51, Can XML
Schema define XSLT? with the specific suggestion of defining a PCDATA
particle to allow a schema author to explicitly specify where character data
would be allowed in a content model.

After lengthy discussion the Working Group declined to adopt your proposal.
The rational was as follows;

1.    Many workgroup members were concerned that such a design would
introduce the SGML 'pernicious mixed content' problem into XML and were
reluctant to adopt it on those grounds.

2.    It was observed that having an element where in some places character
data was allowed and in some places it was not *and* not seperating those
two semantically different regions using markup was a questionable design
choice. It need not be the business of XML Schema to make questionable
design decisions (among which we number, however reluctantly, the design of
the XSL 'template' element's content model) easy to implement.

3.    Many workgroup members considered the simplicity of the existing
design, having a flag to indicate whether character data is valid between
elements or only whitespace, was a virtue worth keeping intact.

It would be helpful to us to know whether you are satisfied with the
decision taken by the WG on this issue, or wish your dissent from the
WG's decision to be recorded for consideration by the Director of
the W3C.

Regards

Martin Gudgin
XML Schema Working Group
Received on Sunday, 8 October 2000 14:25:48 GMT

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