Re: using namespaces to version

[David Carlisle <davidc@nag.co.uk>]

> I take your point, but this is not without some complications;

I fear (alas) that the original "namespace name is just a name"
simplicity of the original namespace REC  has been lost by Schemas
RDDL and other systems assuming a link  between the resource
identified by the namepace URI and the namespace identified by the
namespace name. The Namespace REC makes no such assumption, it just says
the name of a namespace is the identifier of a resource, it doesn't say
the namespace is (or even is related to) the resource.

One of the more common mistakes people make with XSLT (especially with
msxsl) is to get a working stylesheet, then "just" add a reference to a
(XDR) schema via a namespace declaration on the source document.
Then the source document is validated, but the stylesheet no longer
works as all the XPath expressions in the stylesheet no longer match.

Despite the fact that W3C Schema doesn't enforce this method of
specifying the schema and offers the more sane schemaLocation
alternative, I fear you are right and that using the namespace URI to
refer to a schema will turn out to be common, and we are in for a lot
more confusion in this area.

A probable outcome will be pressure on XPath to drop its Namespace
purist approach that "different namespaces are unrelated" and offer
easier syntactic mechanisms to match on elements in "related"
namespaces. Eg *:p to match on a p in any namespace. 
In my view this is a shame, but unavoidable since the "battle"
over whether "it is a goal" of the namespace rec to specify a schema
appears to be lost (or won, depending on your point of view:-)

David

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