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re: Motivations for namespaces (sorry)

• To: xml-dev@l...
• Subject: re: Motivations for namespaces (sorry)
• From: David Megginson <david@m...>
• Date: Wed, 9 Jul 2003 08:43:49 -0400
• In-reply-to: <3.0.6.32.20030709091454.00dd8150@p...>
• References: <3.0.6.32.20030709091454.00dd8150@p...>

Gustaf Liljegren writes:

 > Got some inspiration from the "Looking for an example of a name
 > collission" thread. It's funny that no one seem to be able to
 > present a *good* working example of how namespaces solves name
 > conflicts. I'm not opposing namespaces myself, but I still try to
 > find the right place for them.

Do you want a hypothetical example or a real-world example?
Unfortunately, real-world XML is still a bit hard to come by even
without vocabulary mixing, but it's easy enough to make up credible
examples.  Take something as simply as "vendor-id"; you might have
something like

  <gm:vendor-id>DELCO</gm:vendor-id>
  <ford:vendor-id>3496749DEL (AC DELCO)</ford:vendor-id>
  <chrysler:vendor-id>A564FG345-4</chrysler:vendor-id>

That's an unholy pile of crap, of course, but at least we can sort out
whose crap is whose.  If you want to get into more interesting data
fields, try something like "region"

 > So, assuming that you limit their use to solving name conflicts, is it
 > right to say that namespaces are more useful for document processing?

So far, we don't know, because most of this discussion is
hypothetical.  XML is scarcely used at all for widespread publication
of documents or data -- most XML projects are in-house or inside a
small set of exchange partners.  The few examples of widespread XML,
like RSS and the Linux Documentation Project, are narrowly confined to
a specific vocabulary.

 > In actual use however, namespaces are not limited to solve name
 > conflicts.  It seems they are used more as a way to tell which
 > parts of the document should be processed by which
 > application.

I'd rephrase that slightly -- Namespaces can help an application to
find the parts of a document that it can process.  The difference is
that many different applications may understand or be interested in
names from the same Namespace, so it's not a 1:1 mapping.


All the best,


David

-- 
David Megginson, david@m..., http://www.megginson.com/

• Follow-Ups:
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• References:
  • Motivations for namespaces (sorry)
    • From: Gustaf Liljegren <gustaf.liljegren@b...>

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