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Re: Summary of the QName to URI Mapping Problem

From: Dan Connolly <connolly@w3.org>
Date: Wed, 15 Aug 2001 12:04:27 -0500
Message-ID: <3B7AAB9B.6BE29020@w3.org>
To: Patrick.Stickler@nokia.com
CC: sean@mysterylights.com, kevin@globalplatforms.com, phayes@ai.uwf.edu, www-rdf-logic@w3.org, www-rdf-interest@w3.org
Patrick.Stickler@nokia.com wrote:
> B. The RDF QName to URI mapping function is broken and unreliable:

Not so.

> The RDF spec and the XML Schema spec are the only places I am aware of where
> any such QName to URI mapping function is defined.
> The scope of the XML Schema function (which is ns:name -> ns#name) is
> limited solely to XML Schema instances and ID attribute values within those
> instances, and is not sufficiently broad to address all combinations of URI
> schemes and MIME content type fragment syntaxes. So it can be disregarded.
> The scope of the RDF function (which is ns:name -> nsname) is supposed to
> apply to all cases, for all URI schemes, yet unfortunately, because the
> partition between the namespace and name is lost, can produce collisions
> resulting in ambiguity (which is anathema to the SW).
> I.e. if 'ns1:' = "urn:x:abc" and 'ns2:' = "urn:x:abcd"
>      then both 'ns1:defg' and 'ns2:efg' are mapped to
>      the same URI "urn:x:abcdefg"!

Yes, exactly. The RDF spec, many implementations, and many users
agree on this.

> Yet these are clearly
>      separate resources per their disjunct QName identities

"clearly"? It's not at all clear to me what you mean by this.

> (the fact that the above example is contrived in no way lessens the
>  seriousness of this problem)

Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Wednesday, 15 August 2001 13:04:33 UTC

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