- From: Pat Hayes <phayes@ihmc.us>
- Date: Wed, 9 May 2012 20:34:20 -0500
- To: Richard Cyganiak <richard@cyganiak.de>
- Cc: RDF Working Group WG <public-rdf-wg@w3.org>
I agree with all this, but would note that Michael's feedback does contain a warning that we should be careful not to "simplify" RDF by making the XSD datatypes part of RDF normatively. Which as I had been considering proposing that, is a significant remark that should not be lost in the noise. Pat On May 9, 2012, at 6:42 PM, Richard Cyganiak wrote: > PROPOSAL: Close ISSUE-87 without further action > > PROPOSAL: Resolve ISSUE-88 by adding xsd:duration to the list of supported XSD datatypes in RDF 1.1 > > Details/justifications below. > > Best, > Richard > > > == ISSUE-87 == > > [[ > Some RDF datatypes included in RDF 2004, such as xsd:gYear, have proven troublesome in RIF and OWL due to not being well-behaved w.r.t. ordering. Revisit them to decide if anything is to be done about it. > ]] > http://www.w3.org/2011/rdf-wg/track/issues/87 > > Ivan said: >> I do not see why we would have to do that. These datatypes are obviously useful in RDF and, actually, are used (eg, the microdata->RDF specification recommends using those). OWL and RIF has good reasons not to use them, but that is not binding for RDF imho. > > > http://lists.w3.org/Archives/Public/public-rdf-wg/2012May/0051.html > > Hence the proposal. > > > == ISSUE-88 == > > [[ > RDF 2004 says that xsd:duration does not have a well-defined value space. The value space of xsd:duration has been re-defined in XML Schema 1.1, so this needs to be revisited. > ]] > http://www.w3.org/2011/rdf-wg/track/issues/88 > > Alex Hall reviewed this (Thanks Alex!) and said: > > [[ > The duration definition in XSD 1.1 does have a clearly defined: > • lexical space, which is the same as that in 1.0 > • value space, which is modeled as a [ months as xsd:integer, seconds > as xsd:decimal ] tuple. > • identity condition: two durations are identical if and only if their > months and seconds components are both identical. > • equality relation, which is the same as its identity relation. > • partial ordering. > > Given these revisions, we should consider including xsd:duration in the > list of RDF-compatible XSD types. > ]] > http://lists.w3.org/Archives/Public/public-rdf-wg/2012Feb/0039.html > > Peter went and asked the OWL, RIF and SPARQL WGs to check for objections (Thanks Peter!): > http://www.w3.org/mid/4FA15CC4.4090900%2540gmail.com > > This generated quite some chatter, but the only substantive technical comments on the issue came from Michael Schneider, who summarised his position here: > http://lists.w3.org/Archives/Public/public-owl-wg/2012May/0044.html > > As our intention is to only add xsd:duration to the XSD datatype map (which is optional), Michael's view can be summarized as: > > [[ > Why should we (the OWL WG) care about xsd:duration? It'll be just yet another datatype that is in RDF but not in OWL 2 and RIF. > ]] > http://lists.w3.org/Archives/Public/public-owl-wg/2012May/0044.html > > Which is a view that was also expressed by Pat and others in one of our recent calls. > > Hence the proposal. > > The required document change is simply to do the obvious thing in this section of RDF Concepts ED: > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#xsd-datatypes > ------------------------------------------------------------ IHMC (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 mobile phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Received on Thursday, 10 May 2012 01:34:58 UTC