- From: Gregg Kellogg <gregg@greggkellogg.net>
- Date: Mon, 13 Aug 2012 13:15:35 -0400
- To: Steve Harris <steve.harris@garlik.com>
- CC: Gregg Kellogg <gregg@greggkellogg.net>, Andy Seaborne <andy.seaborne@epimorphics.com>, Pat Hayes <phayes@ihmc.us>, "public-rdf-comments@w3.org" <public-rdf-comments@w3.org>
On Aug 13, 2012, at 2:20 AM, Steve Harris <steve.harris@garlik.com> wrote: > On 2012-08-12, at 02:26, Gregg Kellogg wrote: > >> On Aug 11, 2012, at 1:11 PM, Andy Seaborne <andy.seaborne@epimorphics.com> wrote: >> >>> >>> >>> On 11/08/12 19:40, Steve Harris wrote: >>>> On 11 Aug 2012, at 18:02, Pat Hayes wrote: >>>> >>>>> >>>>> On Aug 11, 2012, at 5:22 AM, Andy Seaborne wrote: >>>>> >>>>>> Hi Dan, >>>>>> >>>>>> On 11/08/12 07:46, Dan Brickley wrote: >>>>>>> Hi Dave, >>>>>>> >>>>>>> On 10 August 2012 19:25, Dave Beckett <dave@dajobe.org> wrote: >>>>>>>> Dear RDF Working Group >>>>>>> >>>>>>> (Just a personal response here) >>>>>> >>>>>> Ditto. >>>>>> >>>>>>> Agreed. This is a niche topic, but I still now thing it is of >>>>>>> occasional use. >>>>>>> >>>>>>> In particular, as a maintainer/editor/contributor for popular >>>>>>> RDF vocabularies (FOAF, schema.org and others) I believe there >>>>>>> is implicit demand for this which is often expressed instead in >>>>>>> terms of requests for new inversely named properties. Whenever >>>>>>> someone asks a vocabulary maintainer to add 'isDirectorOf' >>>>>>> alongside 'director', or asks what the inverse of 'actor', or >>>>>>> 'associatedAnatomy' or 'depicts' is, they are talking about >>>>>>> just this issue. >>>>>> >>>>>> For those people, do you think "^" will read acceptable to those >>>>>> people? (Your point about "isXof" not always being the best >>>>>> choice of name is also interesting.) >>>>>> >>>>>>>> 3. It is not in SPARQL's data syntax. 4. There is a high bar >>>>>>>> to add a new feature to an existing, well understood and >>>>>>>> implemented language like Turtle. This feature does not fit >>>>>>>> that in my judgement. >>>>>>> >>>>>>> Taking those two together, ... >>>>>>> >>>>>>> I only support adding such a construct if it has a comparable >>>>>>> notation in SPARQL. They might not be 100% identical, but the >>>>>>> basic concept ought to either be in both, or in neither. Turtle >>>>>>> and SPARQL share a common heritage in N3; if we can make >>>>>>> teaching them (Turtle and SPARQL; I consider N3 something like >>>>>>> a "Labs project") easier by sharing structure and ideas, we >>>>>>> ought to. >>>>>> >>>>>> A difference between "^:directory" (or the "is...of" syntax) and >>>>>> a property :isDirectorOf is that the "^" solution immediately >>>>>> does the reversing of the written subject and written object. >>>>>> >>>>>> :Ridley_Scott ^:director :Blade_Runner >>>>>> >>>>>> leading to a possible unexpected situation later: >>>>> >>>>> POSSIBLY unexpected. If someone were under the illusion that the >>>>> caret syntax created a new property, they would be surprised or >>>>> disappointed at this point. The answer, surely, is to take pains, >>>>> in writing the documentatio, to explain carefully that it does not >>>>> do this. Your example would be a good one to use is such a >>>>> tutorial, for example. But the fact that a feature MIGHT be >>>>> surprising to someone who DIDNT read the tutiorials and does not >>>>> understand it, it surely not a good argument for not including it. >>> >>> I'm undecided about this feature; I haven't seen a complete proposal >>> yet. There is not absolute argument one way or the other that I've seen >>> and it seems to come down to a value judgement. >>> >>> What does not work for me in this case is the argument like >>> >>> Use Case -> feature solves Use Case -> include feature. >> >> Case #1 >> >> For one thing, it would mean that a Turtle serialization of a SPARQL DESCRIBE (at least one using a Concise Bounded Description) could be generated with a single "subject". For a describe of :gregg in the graph >> >> :gregg foaf:knows :andy . >> : andy foaf:knows :gregg . >> >> could be serialized as >> >> :gregg foaf:knows : andy; ^foaf:knows :danbri . > > Not really relevant to your point but a CBD doesn't include statements where the described URI is the object. http://www.w3.org/Submission/CBD/#definition No, not for IRIs, but step 2 does this for BNodes, including the subjects which reference them as objects. So, yes, my example doesn't strictly adhere to this, but a BNode variant would :gregg foaf:knows _:someone; ^foaf:knows _:someone . That said, even though I've brought forth some potential use cases, I don't feel strongly about including inverse properties myself. I'm probably a +0.5. Gregg > It's a good example of how this type of thing can be used to reduce the number of bytes needed to write a chunk of RDF though. > >> Case #2 >> >> The second scenario I've seen is where several resources need to be declared as having the same type. >> >> foaf:Person ^a :gregg, : andy . >> >> Personally, I prefer is..of, and suggest that we include that as syntactic suggar: >> >> foaf:Person is rdf:type of :gregg, :andy >> >> Reads much better. (Not so much in the first use case). > > Ditto. > > - Steve > > -- > Steve Harris, CTO > Garlik, a part of Experian > +44 7854 417 874 http://www.garlik.com/ > Registered in England and Wales 653331 VAT # 887 1335 93 > Registered office: Landmark House, Experian Way, Nottingham, Notts, NG80 1ZZ >
Received on Monday, 13 August 2012 17:16:15 UTC