Re: [xml-dev] Namespaces best practice: managing dialect evolution --

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

> Since namespaces associate a name with a language dialect, what is a best
> practice for "evolving" that namespace when the language evolves?

This is of course something of a religious question, and you'll get
different answers from different people, but the answer I prefer is that
the namespace name is (only) the name of the language dialect.

So if your new language is close enough to the old one to be called
a new version of the same language, it should be in the same namespace.
If it is really a new language with just an historic association with
the old language, then it should be in a new namespace.

So, MathML 2, being version 2 of MathML, uses the same namespace as
MathML 1. If at some point in the future we decided MathML was all wrong
and we want to do YetAnotherMarkupLanguageForMath then that would be in
a new namespace.

If you change the namespace then, to a namespace aware processor, the
name of _every_ construct in the language has changed, as the name of
each element is the namespace/local-name pair. It's hard to argue that
if you have changed the name of every construct in a language that it is
just an incremental version change.

David

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