- From: Chris Welty <cawelty@gmail.com>
- Date: Thu, 12 Mar 2009 23:21:56 -0400
- To: kifer@cs.sunysb.edu
- CC: Axel Polleres <axel.polleres@deri.org>, public-rif-wg@w3.org, Sandro Hawke <sandro@w3.org>
Michael, The presentation syntax is not for "exchanging concrete languages". The XML syntax, which is not in dispute, is for that purpose. The presentation syntax is pretty much only for *humans* who want to write (and read) rules in BLD. Since you think BLD is useless, you shouldn't care what syntax humans want to use to write&read it. You can use your personal syntax for the dialect that you find useful, as long as it is 1-1 translatable to the XML syntax there is no problem. In fact, the ability to have multiple presentation syntaxes seems to me to precisely *demonstrate* the advantages of RIF. In some sense, each of these syntaxes can be thought of as different languages which have very good interchange properties through RIF-XML. Neither RDF nor OWL have suffered from multiple equivalent syntaxes (though the same arguments were made against them at the time), I see no evidence that it would bloat or harm adoption of RIF at all. Quite the opposite. -Chris Michael Kifer wrote: > Axel, > pls see my earlier response to Sandro. > I believe that all these proposals are leading the group astray and causing us > to loose sight of what RIF is about. To me, RIF is not BLD and not PRD, but a > framework for dialects. BLD, IMO, is mostly useless. I see the future of RIF in > dialects that extend BLD. You are proposing to introduce completely useless > (IMO) bloat into what is supposed to be a framework for exchanging concrete > languages. > > michael > > > On Thu, 12 Mar 2009 18:35:09 +0000 > Axel Polleres <axel.polleres@deri.org> wrote: > >> Michael Kifer wrote: >>> On Thu, 12 Mar 2009 16:44:10 +0000 >>> Axel Polleres <axel.polleres@deri.org> wrote: >>> >>>> Michael Kifer wrote: >>>>> I think the origin of this thread was your proposal to use triples {a b c} >>>>> instead of frames. This is unacceptable because frames are not triples. >>>> SWC defines them as corresponding [2]: >>>> >>>> "This means that whenever a triple s p o is satisfied, the corresponding >>>> RIF frame formula s'[p' -> o'] is satisfied, and vice versa[...]where >>>> s', p', and o' are RIF symbols corresponding to the RDF symbols s, p, >>>> and o, respectively." >>> I am saying: frames are not triples, but triples are frames. >> That's ok. >> >>>>> You can have a[b->c d->e] etc. >>>> That is not a problem, in PS I would likewise suggest to allow not only >>>> frame style but also turtle style abbreviations, cf. [1] i.e. >>>> >>>> { a b c; d e } etc. >>> Hmm. You don't expect me to like that, do you? >> There are many people who do like and regularly use that. >> >>>>> Second, {...} is not a good syntax because it means sets. >>>> not in RIF. From that point of view, one could equally argue "[...] is >>>> not a good syntax because it means array or lists". So, again, I don't >>>> see the problem. >>> Set notation is fundamental, and there has been demand for that in use case >>> examples. I didn't introduce that before because originally the >>> presentation syntax was supposed to be abstract syntax. But now when we are >>> moving towards a concrete syntax this is on the agenda. Aggregates are >>> definitely on the agenda even if the set syntax won't make it. >>> >>>>> This is what I was >>>>> planning to use for aggregates (I proposed this several months ago in an email) >>>>> and for shorthands like a[b->c b->d] == a[b-> {c d}] >>>> I do not see this approved anywhere, as of yet. >>> See above. >>> >>>> Alternatively, I suggest >>>> for that case to use the Turtle style abbreviation [1] using commata for >>>> separating multiple values, i.e. >>>> >>>> { a b c, d } >>>> >>>> or, in frame style: >>>> >>>> a[b-> c, d] >>>> >>>> My preferences is compatibility among W3C promoted languages (RIF, RDF, >>>> SPARQL). >>> This is doomed to failure and is a waste of time. >> Well, we are already there: it needs no time at all, if we just accept >> Turtle style patterns in { ... } as a notation for conjunctions of >> frames. So, no additional time needed, and no time wasted. >> >>>> FWIW, I don not necessarily propose to *replace* frames, but to >>>> allow Triple/Turtle style syntax alternatively at lease for the sake >>>> of this aimed compatibility. Would that be acceptable for you? >>> No. Why duplicate and complicate? >> It does not complicate anything in my opinion, and it is a reasonable >> alternative to frames style syntax with - for a W3C WG in the Semantic >> Web activity - a significant community behind. >> >>>> The SW community is becoming very used to this kind of syntax and a >>>> compatible PS would certainly be appreciated from that side. >>>> >>>> BTW, I would actually not expect too many people wanting to mix Turtle >>>> style and frame style syntax in the same PS document... >>> Don't forget that RIF is an exchange syntax despite all the talk about the >>> presentation syntax. If you want to use turtle syntax then use Turtle syntax >>> and translate it to (XML) RIF. >> Just to clarify: Turtle is not a rules language, but it can model the >> part covering conjunctions of frames/triples. >> >> best, >> Axel >> >>> cheers >>> michael >>> >>> >>>> best, >>>> Axel >>>> >>>> 1. http://www.w3.org/TeamSubmission/turtle/#sec-tutorial, Section 2.3. >>>> 2. http://www.w3.org/2005/rules/wiki/SWC#RDF_Compatibility, Section 3 >>>>> michael >>>>> >>>>> On Thu, 12 Mar 2009 09:23:12 +0000 >>>>> Axel Polleres <axel.polleres@deri.org> wrote: >>>>> >>>>>> Sandro Hawke wrote: >>>>>>> Talking after the call today, Axel made a good case for adopting the >>>>>>> other solution to the infix-operators problem, namely to pay attention >>>>>>> to whether there is a space between the "f" and the "(" in "f(x)". So >>>>>>> "f (x)" is two terms, and "f(x)" is one term. This is my own >>>>>>> preference, and what I implemented before the task force telecon (where >>>>>>> I got talked out of it). One of Axel's considerations is alignment with >>>>>>> SPARQL and other RDF-related languages, in user training materials. If >>>>>>> we go with this kind of space-sensitivity, then we can have both the >>>>>>> F-Logic and N3 styles available for expressing triples, so you can write >>>>>>> your exampes in either one. And you can use commas if you want, but you >>>>>>> can also leave them out. This means my parser should be able to handle >>>>>>> all the existing examples and test cases... a pretty big win, really. >>>>>>> The one thing people can't do is write "f (x)" when they mean "f(x)". >>>>>>> >>>>>>> -- Sandro >>>>>> In that context, note that in the proposed PS we hav space-sensitivity >>>>>> already anyways, for the '-' operator vs. dashes within IRIs. So, I >>>>>> think that additional space-sensitivity would be totally acceptable. >>>>>> >>>>>> Axel >>>>>> >>>>>> >> > > -- Dr. Christopher A. Welty IBM Watson Research Center +1.914.784.7055 19 Skyline Dr. cawelty@gmail.com Hawthorne, NY 10532 http://www.research.ibm.com/people/w/welty
Received on Friday, 13 March 2009 03:22:52 UTC