- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Fri, 21 Oct 2011 12:24:32 +0100
- To: public-rdf-wg@w3.org
On 21/10/11 12:01, Steve Harris wrote: > On 2011-10-21, at 11:19, Andy Seaborne wrote: >> >> On 20/10/11 14:05, Steve Harris wrote: >>> On 2011-10-20, at 13:47, Sandro Hawke wrote: >>> >>>> On Thu, 2011-10-20 at 13:21 +0200, Dan Brickley wrote: >>>>> On 20 October 2011 13:13, Steve Harris<steve.harris@garlik.com> wrote: >>>>>> I wouldn't be comfortable with marking Seq as "archaic" or similar unless there's a viable alternative, and I don't think List counts. >>>>> >>>>> Me neither. Nor "quaint", "twee", "retro" or "regrettable". It's just >>>>> what it is, with no great mystery or confusion. >>>> >>>> Actually, there's a great deal of confusion. Please do explain -- in >>>> one sentence for newbies -- why we have both Seq and List, and with Seq >>>> better supported in RDF/XML and List better supported in Turtle, and how >>>> someone should decide which to use. >>> >>> Seq has the advantage that it's much easier to query with SPARQL. Still not great, but much easier. >>> >>> Finding the 3rd member of a list: >>> >>> Seq >>> >>> SELECT ?m3 >>> WHERE { >>> <x> rdf:_3 ?m3 >>> } >> >> If you assume a notion of well-formedness: else: >> >> :x rdf:_1 1 ; >> rdf:_1 10 ; >> rdf:_1 11 ; >> rdf:_2 2 ; >> rdf:_9 3 . > > I don't see how that's an issue - there isn't a 3rd member in that case, which is a bit at odds with the mathematical definition of a Sequence, but a reasonable thing to want to model. The text does not say anything about the values: it's just a sequence, in a weaker sense than an array having slots at 0, 1, 2, ... [[ the rdf:Seq class is used conventionally to indicate to a human reader that the numerical ordering of the container membership properties of the container is intended to be significant. ]] "numerical ordering" http://www.w3.org/TR/2004/REC-rdf-schema-20040210/#ch_seq hence the well-formedness idea. Others see multiple rdf:_1 as meaningful. Andy
Received on Friday, 21 October 2011 11:25:02 UTC