W3C home > Mailing lists > Public > www-tag@w3.org > February 2005

Re: Significant W3C Confusion over Namespace Meaning and Policy

From: Robin Berjon <robin.berjon@expway.fr>
Date: Fri, 18 Feb 2005 11:18:25 +0100
Message-ID: <4215C0F1.8090407@expway.fr>
To: Patrick Stickler <patrick.stickler@nokia.com>
Cc: www-tag@w3.org

Patrick Stickler wrote:
> Namespace documents are not backwards compatible with existing
> use of namespace names -- since one cannot impose a reinterpretation
> of what those namespace name URIs identify such that they would
> identify namespace documents.

And they don't. It was always an option that one could perhaps retrieve 
a representation from a namespace URI and putting something there 
doesn't change the nature of namespace URIs in any way.

> Namespace documents seem like a good idea in contexts where there
> is a 1:1 relationship between namespace and model or namespace
> and vocabulary, but it will not scale as would be needed for
> a trully global solution.

It might not meet some needs but 1:1 relationships between namespace and 
(evolving, but slowly) vocabulary is the very vast majority of cases. 
They hit the sweet spot nicely.

> E.g. something analogous to <?xml-stylesheet ...?> is an option:
> <?xml-model href="http://some.org/some/model/some/version"?>

Anything that requires users to type in the above with no obvious 
benefit to them cannot work.

> It also helps the "islands of XML" problem where different
> XML languages are intermixed (e.g. XHTML+MathML+SVG) such
> that the model identified constitutes a particular application
> of those XML languages where the rules for conflict resolution
> and other integration issues are defined for the model, and
> applications supporting the model will then know how to
> properly interpret the data instance.

I strongly doubt that the problem of compound documents can be made to 
be that simple :)

> So, in short, namespace documents and RDDL are IMO searching
> for one's lost keys under the street light because that's where
> one can see. It misses the essential points that (a) namespaces
> really are just syntax,

Syntax with a convenient choice in the form of URIs.

> (b) from a management perspective,
> trying to manage references to related resources in a single
> document is highly impractical and non-scalable, and

Again, for the large majority of cases it's highly practical and trivial 
to scale. I'm sure there are cases that are not covered by this 
approach, but the degree of complexity at which an RDDL document becomes 
insufficient likely corresponds to a level at which users are willing to 
pay the price of a more complex solution — and conversely anything that 
requires anything more complex than RDDL will have too high a cost for 
people with simple needs to bother producing it.

Robin Berjon
   Research Scientist
   Expway, http://expway.com/
Received on Friday, 18 February 2005 10:18:24 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:56:07 UTC