- From: Misha Wolf <Misha.Wolf@reuters.com>
- Date: Tue, 13 Jun 2006 14:45:53 +0100
- To: Harry Halpin <hhalpin@ibiblio.org>, www-tag@w3.org
- Cc: public-rdf-in-xhtml-tf@w3.org, newsml-2@yahoogroups.com
Hi Harry, > I think Henry's pointing to the conceptual problem with making > CURIEs a "superset" of QNames. Unlike CURIEs, QNames (at least as > I've been able to discover, correct me if I'm wrong - the spec just > seems silent) do not define an algorithm for converting an entire > QName to a IRI, and by "algorithm" we're not talking about anything > fancy - but just concatenating the namespace URI and the local name > as strings, which is what most processors do anyways - as pointed > out by Borden [1] and raised to the TAG [2], who seemed to be answer > a sort of different question in their finding. I contest the assertion that there is some agreed rule for how to obtain an IRI from the {prefix, suffix} of a CURIE. > Yet a processor can map (expanded name, local name) like > (http://www.w3.org/1999/XSL/Transform,template) to an IRI by doing: > > http://www.w3.org/1999/XSL/Transformtemplate > > Or by doing: > > http://www.w3.org/1999/XSL/Transform#template > > And it seems both would be equally valid or invalid, depending on > your opinion. If this is so, it should be fixed asap. > So by making CURIEs a superset of QNames is a bit difficult as long > as the QName (namespace prefix, local name)=>IRI construction is > unspecified. This is not a problem, as the same is true for CURIEs. > And so using the ":" for QNames and CURIEs means that given any > "x:y" element or attribute name one couldn't tell whether one meant > an IRI or a (namespace prefix, local name). So there seems to be two > choices: > > 1) Unspecified IRI construction for the entire (namespace prefix, > local name) a *bug* in QNames and should be corrected post-hoc by > the CURIE proposal. If this is the case, then CURIEs should use ":" > and then make themselves a superset of QNames. It is not a bug in QNames. > or > > 2) Unspecified IRI construction in QNames is a *feature* and so > CURIEs should exist as a parallel standard, and so use [insert > character besides ":" here] in order to keep confusion between > QNames and CURIEs at a minimum. There is no difference between QNames and CURIEs in this matter. > My earlier post is that some communities (i.e. some of the > microformat people I talked to at WWW2006) mentioned that they > would like another character besides : for "namespaces in > microformats." Next time I'll just tell them to escape their > colons :) > > [1] http://www.openhealth.org/RDF/QNameQuagmire.html > [2] http://www.w3.org/2001/tag/issues.html#rdfmsQnameUriMapping-6 Regards, Misha ------------------- NewsML 2 resources ------------------------------ http://www.iptc.org | http://www.iptc.org/std-dev/NAR/1.0 http://www.iptc.org/std-dev | http://groups.yahoo.com/group/newsml-2 To find out more about Reuters visit www.about.reuters.com Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Reuters Ltd.
Received on Tuesday, 13 June 2006 13:46:30 UTC