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Re: XML validity and namespaces

From: Robin Berjon <robin.berjon@expway.fr>
Date: Tue, 05 Apr 2005 16:53:42 +0200
Message-ID: <4252A676.3050608@expway.fr>
To: noah_mendelsohn@us.ibm.com
Cc: www-tag@w3.org

noah_mendelsohn@us.ibm.com wrote:
> Robin Berjon writes:
>>And is it not one of the greatest ironies of XML
>>Schema that it failed to learn from that lesson
>>and therefore didn't provide simple and
>>straightforward means to describe extensibility in
>>schemata?
> 
> It is indeed, though to be fair, there was and to some degree still is a 
> great deal of disagreement as to what evolution strategies people wanted 
> to use for their instances.   The job of schema is to make it easy to 
> describe evolving constraints on those instances, and the community was 
> nowhere near consensus on what idioms were to be described.

Yes, it was not my intention to point fingers, just to underline the 
fact that we seem to have carried that precise irony of extensibility 
(or lack thereof) much farther into the XML architecture than just DTDs.

Have you given thought to NVDL (fka NRL) in that context? I don't 
remember seeing any mention of it in the draft E&V finding (and can't 
seem to find any). I've been using it to specify that SVG accepted 
foreign namespaces anywhere and a few other such rules without having to 
put a single wildcard in the SVG schema. It doesn't solve every single 
extensibility issue out there, but it certainly helps a lot. It felt 
like the X was back in XML for the first time in a long while.

-- 
Robin Berjon
   Research Scientist
   Expway, http://expway.com/
Received on Tuesday, 5 April 2005 14:53:43 GMT

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