- From: Pat Hayes <phayes@ihmc.us>
- Date: Sun, 20 Jun 2010 10:05:23 -0500
- To: Alan Ruttenberg <alanruttenberg@gmail.com>
- Cc: Andy Seaborne <andy.seaborne@talis.com>, Paul Gearon <gearon@ieee.org>, Norman Gray <norman@astro.gla.ac.uk>, Semantic Web <semantic-web@w3.org>
On Jun 20, 2010, at 8:32 AM, Alan Ruttenberg wrote: > On Sat, Jun 19, 2010 at 5:05 PM, Pat Hayes <phayes@ihmc.us> wrote: >>> As Paul says, update is not pretty. >>> >>> The complete solution would be to have lists as first class data >>> object in the RDF model (as well as bags). >> >> Um, they are. Lists as described by the RDF List vocabulary are >> *exactly* the LIsp model of a list. > > Nope. An RDF list doesn't constrain rdf:first to be single value. It > doesn't constrain rdf:rest to be either a single rdf:list or rdf:nil. > So you can make all sorts of structures using rdf lists that don't map > to lisp lists. > Yes and no. RDF doesn't "make" anything, it describes things. Lists as described by RDF have exactly the structure of LISP S-expressions. However, just as with any other descriptive language, you can also say nonsense in RDF. In particular, you can say things using the list vocabulary that don't describe any actual lists, just as you can assert, once you have a property fatherOf, that someone is their own father. My point to Andy was that what one might call the RDF List 'model' was quite conventional, and that SPARQL could simply assume that RDF list descriptions were correct and complete, and it would be acceptable for queries to fail when the RDF was list- crazy in the kind of way you describe. But I apparently misunderstood his point, so this is now moot. Pat > -Alan > ------------------------------------------------------------ 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 Sunday, 20 June 2010 15:07:43 UTC