Fw: Namespaces

Oren Ben-Kiki oren at capella.co.il
Thu Feb 4 09:50:30 GMT 1999

OK, I see I'm totally lost here.


Is it possible to recast the namespace recommendation as a transformation
from an XML tree with 'xmlns' attributes and '...:' prefixes into a tree
which doesn't have them, but with modified element and attribute names, such
that the semantics of the resulting tree under the rest of the relevant
recommendations (ignoring namespaces) is preserved? One would of course have
to pass the DTDs (or other schema files) through the same transformation.

Note that this may require defining a textual form for the transformed tree
(using "...^...", or "{..}..", or whatever).

If so, then we'll have a clear definition of just how to add a namespace
processor on top of a normal XML processor. The reverse transformation could
be used for emitting XML trees. The rest of the XML standards could pretty
much ignore namespaces altogether. The endless threads of "what are
namespaces this week" would go away. Yes, I know, I'm dreaming (or raving

If this isn't possible, and from what I'm reading this seems a real
possibility, then I'd like to know the details - in particular, I want to
hear the advantages gained by this decision. Is it some attempt to mix
together namespaces and other issues - such as mixed content, combining
documents, extending DTDs, etc.? MVHO is that such issues should be solved
separately of the unique naming issue, but I realize that the W3C has a
tradition of mixing together issues which seem separate to me :-)

James' document uses the transformation approach. It stops short of claiming
the preservation of semantics. When I asked about a particular equivalence
issue (relationship between an attribute name and an element name, given
that none/one/both of them are expanded), he said:

> I would prefer not to answer this since I don't think the XML Namespaces
> Recommendation needs to take a position on this. All the Namespaces
> Recommendation does is provide a mechanism which allows element type
> names and attribute names to be qualified with a URI. How other
> applications or specifications (such as RDF or XML Schemas) choose to
> exploit this mechanism is up to them.
> However, if I was forced to answer, I would say that the relationship
> was not the same.

These two statements seem contradictory to me - if "all" the namespaces do
is prefix the names with a URI, why should the relationship between expanded
names be different then that between "normal" names? If this relationship is
"application defined" for normal names (as James implies), then doesn't it
remain "application defined" when the names are expanded? Anyway, how come
it is "application dependent" - don't DTDs and schema language have a lot to
say about it?

My head is starting to ache.

Way in over my head,

    Oren Ben-Kiki

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)

More information about the Xml-dev mailing list