Re: using namespaces to version

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

Hi folks,

> I'm wondering if anyone on the list has any strong opinions about
> the use of namespaces for versioning.

I think it's a bad idea: To a namespace aware processor if you
change the namespace then you change the effective name of every
construct in the language.

It seems to me that two languages with no names in  common are not
versions of each other but rather two different languages.

Thus (to use the example you gave) any language that can reasonably be
called a version of MathML ought use the MathML namespace. If some
future language is sufficiently different that it is no longer MathML
version n but rather NewSuperMathML version 1 then it should have a new
namespace but as a consequence it will share no elements in common with
MathML and all existing XPath queries into MathML structure (for
example) will not apply to this namespace.

This argument was of course at the heart of the "p is a p is a p"
debate over three (or as it thankfully turned out, one) namespaces for
XHTML

David


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