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Q to implementers: Resource identifiers - XML Names and/or (concatenated) URIs? (was RE: rdfs.isDefinedBy...)

From: Jeremy Gray <jeremy@jeremygray.ca>
Date: Thu, 6 Jun 2002 07:36:20 -0700
To: <www-rdf-interest@w3.org>
Message-ID: <000301c20d67$86891ac0$5a16b742@Dora9>

(This may end up as a double-post, so if it does, please disregard whichever
version appears second)

Setting aside for the moment the whole issue of namespace URIs and their
potential relation to RDF Schema documents and the network resolution
thereof I have a question for RDF application implementers out there
regarding their use of Resource identifiers in the form of XML Names vs.
concatenated URIs:

Since it is obvious that the working group(s) responsible for RDF for one
reason or another (i.e. current charter) are not in a position to properly
address RDF's current mangled interpretation of Namespaces in XML and other
identifier-related issues such as:

- if RDF/XML requires prefixes before each attribute, it is simply not
Namespaces in XML -compliant XML
- the suggested XML Names -> URI concatenation process produces collisions
- the suggested URI -> XML Names splitting method is so flawed as to not be
responsibly implementable (i.e. you can't generate valid LocalParts by
splitting on non-Name characters, but can if splitting on non-NCName
characters. However, using the latter method produces differently invalid
results, e.g. if splitting
urn:NewsML:afp.com:20000811:010607144425.x6pxrl6k:1)

Without getting into a huge discussion about each of the example bullets
above (unless you have specific comments regarding their effect on your
implementation) and without starting yet another discussion about how simple
it would be to fix these issues and how many benefits could be reaped from
their correction if only an RDF 1.1 or some such could be created that
natively includes the concept of namespaces, I'd like to hear how
implementers have dealt with these issues in light of the fact that the
Working Group(s) can't/won't. Are you fully supporting Namespaces in XML in
your serialization? Internally? Are you following the WG-recommended
concatenation and splitting processes? If not, what are you doing instead?

My company, for example, intends to produce behaviour indicative of full and
correct interpretation of the Namespaces in XML specification so that
behaviour both inside and outside of our system is consistent. It may not be
strict RDF, but it has a better chance of producing correct results. Since
Namespaces exist within our RDF system (once again, NOT for schema
identification or resolution, just for identifiers), and since we do expect
information to flow to and from other systems operating in terms of the
naive RDF 1.0 + issue tracking interpretation, we may create something
analogous to the concatenation/stripping process but which is based on a
list of known namespaces on which splitting/merging can occur when desired
instead of the current half-baked process. Since those external applications
will be creating collisions and improperly splitting URIs anyway, we don't
honestly expect 100% correct integrated behaviour in any case, but will try
to integrate with them as best as we can.

How are you addressing Namespaces in XML -related issues in and around RDF?

Thanks now for your time and in advance for your comments.

Jeremy Gray
Received on Thursday, 6 June 2002 10:36:51 GMT

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