Re: [TURTLE] Turtle Inverse Properties


On Sat, Aug 18, 2012 at 10:53:44PM -0400, Lee Feigenbaum wrote:
> On 8/17/2012 3:58 PM, David Booth wrote:
> >On Fri, 2012-08-17 at 11:30 -0700, Gavin Carothers wrote:
> >[ . . . ]
> >>Objections to both original syntax and revised syntax
> >>=====================================================
> >>
> >>Turtle is a reasonably settled languages, changes made by the working
> >>group so far have been limited to areas of existing differences in
> >>implementation.
> >>
> >>No demand over years of implementation experience
> >I think that may be slightly misleading, because Turtle was not
> >previously standardized, and hence was on the same footing as N3, and
> >those who wanted to use this feature simply considered their RDF to be
> >N3 instead of Turtle.  I.e., there was no *need* to demand it in Turtle
> >because Turtle was not previously chosen over N3 for standardization.
> In turn, I think this is misleading -- Turtle has far more
> implementations than N3, and so -- standard or not -- has had far
> more opportunity for users of those implementations (of which there
> are many) to demand this feature in a volume that would have lead to
> it being adopted. This has not happened even a single time that I
> know of. Given the scarcity of N3 implementations, I sincerely doubt
> that users simply abandoned their existing Turtle toolkits and
> picked up an N3 toolkit instead so that they could use inverse
> property syntax.

I would sincerely doubt you would adopt a very rich toolkit like N3 just to get inverse properties, especially when implementations are quite sparse. You would probably just work around it in Turtle. Hence the fact that it hasn't been done doesn't mean this feature wouldn't be useful. As I see it, it is syntactic sugar that would make Turtle much easier to use for some cases - in particular converting legacy data structures.


> I haven't weighed in on the discussion before, so I'll give my
> feeling here. I'm not motivated by the use cases for this feature,
> and I think that the costs (as enumerated by Gavin and others) are
> way too high to change Turtle in this way. I support not adding
> inverse property syntax to Turtle.
> Lee
> >
> >[ . . . ]
> >>2. Add ^ property path syntax to Turtle.
> >+1.  I like it a lot.  Conciseness improves clarity, which reduces
> >errors.
> >
> >>     1.1. Allowing "literals" in any subject position by syntax,
> >>however the RDF model disallows literal as subject. (As SPARQL in
> >>query blocks, however SPARQL disallows path syntax in triple assertion
> >>syntax)
> >+1.  SPARQL could be fixed in the next version to allow path syntax in
> >triple assertion syntax if the SPARQL WG is too tired to change that in
> >SPARQL now.
> >
> >>     1.2. Attempting to limit use of "literals" in subject position to
> >>only ^ predicates in grammar (Not as SPARQL and SPARQL disallows path
> >>syntax in triple assertion syntax.)
> >-0.5.  No need to complicate the grammar.
> >
> >>3. Add both ^ property path syntax and "is ... of" syntax.
> >-1.  To my mind, that would just add pointless complexity.  Standardize
> >one or the other but not both.
> >
> >
> >

Received on Tuesday, 21 August 2012 12:41:18 UTC