- From: <jos.deroo@agfa.com>
- Date: Sun, 6 Feb 2005 01:07:29 +0100
- To: phayes@ihmc.us
- Cc: Dan Connolly <connolly@w3.org>, "Eric Prud'hommeaux" <eric@w3.org>, www-archive@w3.org
>> I was a good boy and tried out the XSLT approach. Praise and cash >> donations cheerfully accepted. > > Sheesh, I'm impressed. By you, that is, not by XSLT. D3 >> B2, I'd say. > > More I think about this, more I like the idea of allowing these > thingies, but putting them in a the query in a place where they > really are forced to be on a special stage, as it were. How about > something like an explicit 'filter' construct, so we might have > >> SELECT ?annot ?author >> WHERE { (?annot dc:creator ?author) >> (?annot dc:created ?when) } >> FILTER ( isURI(?author) || > ?when < xs:dateTime(20050101T00:00:00Z) ) > > The point being that 'AND' reads altogether to much like a > conjunction, as though you were just tacking an extra piece on to the > RDF pattern in the WHERE; whereas this lets us have warnings like > "filters cannot be represented in RDF" > > Dan & Jos, would this make you any happier? Hm.. thinking about the subject of this thread "..how queries relate to rules and proofs" I think a query is like a filter rule {WHERE-triples} => {SELECT-triples} actually fitting nicely with sequent proofs and I don't see how that syntactic FILTER evidence fits with rest of proof, so I really would keep it in the I/O of the proof engines (but of course the stuff from AND clause such as e.g. ?X math:lessThan 30 I would put in the WHERE-triples) -- Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Sunday, 6 February 2005 00:08:27 UTC