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RE: [rdfmsQnameUriMapping-6] Algorithm for creating a URI from a QName in RDF Model?

From: Julian Reschke <julian.reschke@gmx.de>
Date: Wed, 22 May 2002 20:35:08 +0200
To: "Brian McBride" <bwm@hplb.hpl.hp.com>, "Tim Bray" <tbray@textuality.com>, <www-tag@w3.org>
Cc: <www-tag@w3.org>
Message-ID: <JIEGINCHMLABHJBIGKBCOEEMEKAA.julian.reschke@gmx.de>
> From: www-tag-request@w3.org [mailto:www-tag-request@w3.org]On Behalf Of
> Brian McBride
> Sent: Wednesday, May 22, 2002 7:53 PM
> To: Tim Bray; www-tag@w3.org
> Cc: www-tag@w3.org
> Subject: Re: [rdfmsQnameUriMapping-6] Algorithm for creating a URI from
> a QName in RDF Model?
>
>
> Hi Tim,
>
> Thank you for initiating this discussion.  I'm sorry I missed it
> earlier; I
> try to monitor the TAG traffic, but there is quite a lot; I'm
> sure you know
> the problem.
>
> If you will forgive me making a process suggestion, when the TAG
> wishes to
> stimulate discussion on a topic which is known to affect/be of
> interest to
> specific WG's, would it be a good idea to contact the WG directly.
>
> I have sent a pointer to this message to the RDFCore WG, so they know now.
>
> Anyway to more substantive matters:
>
> At 06:03 10/05/2002 -0700, Tim Bray wrote:
> >>Raised by: Jonathan Borden
> >>   http://lists.w3.org/Archives/Public/www-tag/2002Jan/0178
> >>Raised date: 22 Jan 2002
> >>Accepted by TAG 28 Jan 2002:
> >>   http://www.w3.org/2002/01/28-tag-irc
>
> As background information, RDFCore had an issue:
>
>    http://www.w3.org/2000/03/rdf-tracking/#rdfms-qname-uri-mapping
>
> which was raised by Jonathan.  RDFCore decided not to change its current
> algorithm for computing a URI form a qname; the resolution is
> documented at
> the URL just given.
>
> My interpretation of this decision is that the WG felt that, considering
> just the needs and effects of RDF alone, there was insufficient reason to
> justify a change to the existing specification.
>
> The tag, with a broader viewpoint, may come to a different
> conclusion.  If
> it does so, I would hope that the RDF community would move quickly to
> support it.
>
> The essence of Jonathon's issue seems to be encapsulated in:
>
> [[
> The problem is that
> XML Schema identifies types by QName, and unless there is a reasonable
> translation between QNames and URIs, RDF is likely to become more broken
> with time.
> ]]
>
> and our understanding of what is a "reasonable" algorithm for translating
> between URI's and qnames.
>
> I suggest that an early step in pursuing this issue should be the
> production of a test case which demonstrates the unreasonableness of the
> algorithm used by RDF.
>
> ...

As far as I understand the issue, *any* algorithm that attempts to map

(uriref, name) -> (uri)

will be unreasonable if it attempts to produce a URI in the same URI schema
as the namespace name. This is because for an arbitrary URI scheme, there
will be no obvious way to produce new valid URIs without having a priori
knowledge about this URI scheme's syntax (and semantics).

For instance, consider the qname ("tel:++492512807760", "foo"). If you want
to things even more interesting, try ("tel:++492512807760#bar", "foo").

Regards, Julian
Received on Wednesday, 22 May 2002 14:35:43 UTC

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