- From: Michael Kifer <kifer@cs.sunysb.edu>
- Date: Tue, 06 May 2008 08:07:17 -0400
- To: Axel Polleres <axel.polleres@deri.org>
- Cc: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
> Michael Kifer wrote: > > 1. Curie, <...> > > My main concern with context sensitivity is that it will confuse people > > (like it did several members of this group) to think that the stuff after > > ^^ are constants by themselves. This requires that we explain things > > carefully and, possibly, will cause more confusion. The more context > > sensitivity we have, the more explaining we have to do, and no amount of > > explanation might be enough. > > > > My strong preference is to limit context sensitivity or completely > > eliminate it, but in the spirit of reconciliation I am also willing to go > > with majority :-) > > > > By the way, I did not understand what PNAME_LN and PNAME_NS are. I guessed > > that the latter is the foo:bar thingie, but what is LN? > > see the resepctive productions at > http://www.w3.org/TR/rdf-sparql-query/#rPrefixedName > http://www.w3.org/TR/rdf-sparql-query/#rPNAME_LN > http://www.w3.org/TR/rdf-sparql-query/#rPNAME_NS OK. Perhaps somebody can explain this a bit more? It looks like that syntax allows things like prefix: and abc...de. > > 2. PREFIX. > > I do not like the syntax PREFIX(...), since it suggests that this is a > > fact-formula. > > If it causes ambiguity then we need to change it, indeed. > > > However, I am ok with it as a directive (with the same syntax > > as you suggest) in the preamble of the document, along with Import and > > whatever else we'll end up having there. > > fine for me. ok > > 3. Regarding your response to Hassan suggesting " instead of \", I do > > not understand your reasoning. You were so gang-ho on brevity and now > > suddenly 6 characters instead of two? > > > > If you want to use entities, like ", then why not use them > > throughout? That is, instead of rif:iri use &rif;iri, and we are done away > > with context-sensitive curies and all that. (This is what I was proposing > > from the very beginning except that I was suggesting to use : instead of > > &...;.) > > Probably, you, Sandro, and Hassan are right that XML entities in the > presentation syntax are confusing. Alternatively, escape sequences like > defined in SPARQL seem to be better: > http://www.w3.org/TR/rdf-sparql-query/#grammarEscapes > http://www.w3.org/TR/rdf-sparql-query/#codepointEscape > > Does that look more reasonable to you? SPARQL escapes? These look to me like good old C language escapes. These are fine, but do not assume that the world began with Sparql. --michael > I agree that we should focus on the XML syntax issues now as suggested > in Sandro's mail. But I guess the SPARQL escaping mechanism should do > for the moment... I assume hey spent some thinking on it and in case > there are problems, we can revisit this point upon feedback. > > best, > Axel > > > --michael > > > >> Sorry, this might be unconvenient, but due to an urgent meeting whch I > >> cannot shift, I have to pass on tomorrow's telephone conference. > >> > >> So, in order not to hamper progress for DTB, I suggested several options > >> to vote over concerning the points in my mail at [1]. > >> > >> http://lists.w3.org/Archives/Public/public-rif-wg/2008Apr/0194.html > >> > >> 1) CURIEs: As for 1) there were extensive discussions on the > >> mailinglists, it seems that [2] is kind of a minimalistic proposal > >> whereas [3] is richer. I haven't seen a grammar for [2] yet, so let me > >> put both options on the table again. > >> > >> a), cf. [3] > >> > >> ANGLEBRACKIRI ::= '<' IRIRef '>' > >> > >> STRING ::= '"' ANYSTRINGWITHOUTQUOTES '"' > >> > >> CURIE ::= PNAME_LN | PNAME_NS > >> > >> Const ::= ANGLEBRACKIRI > >> | CURIE > >> | STRING^^ANGLEBRACKIRI > >> | STRING^^CURIE > >> > >> b), cf. [2] > >> > >> ANGLEBRACKIRI ::= '<' IRIRef '>' > >> > >> STRING ::= '"' ANYSTRINGWITHOUTQUOTES '"' > >> > >> CURIE ::= PNAME_LN | PNAME_NS > >> > >> Const ::= CURIE > >> | STRING^^ANGLEBRACKIRI > >> | STRING^^CURIE > >> > >> > >> Comparison between a) and b): The only difference is that b) doesn't > >> allow ANGLEBRACKIRIs as Consts, thus making it N3 incompatible, but > >> well. Both are context-sensitive. There were some other discussions > >> introducing some form of "aliasing" [2,4], but since I didn't see a > >> grammar for this and thus it is unclear whether these would introduce > >> ambiguity, I suggest to keep it out. > >> > >> I suggest to vote between these two, my own vote is for a), though I am > >> willing to obey a majority vote for b). I personally would be unhappy > >> with N3 incompatibility [5,6] when voted for b), since none of the > >> arguments given so far were technical in the sense of that there would > >> be any problem with the grammar for a). For an additional argument, see > >> also 4) below. > >> > >> 2) FULL URIs for RIF (see also [7]) > >> > >> From the original proposals, the following 2 seem to have "survived" > >> the discussions so far: > >> > >> a) define own prefixes (separate for functions and predicates): > >> > >> http://www.w3.org/2007/rif-builtin-predicates#numeric-equal > >> > >> http://www.w3.org/2007/rif-builtin-functions#concat > >> > >> c) reuse XPath/Xquery fn: prefix (problem: not prefix defined for op: we > >> still would need to invent one): > >> > >> http://www.w3.org/2005/xpath-??????#numeric-equal > >> > >> http://www.w3.org/2005/xpath-functions#concat > >> > >> I personally prefer a) and suggest to > >> > >> PROPOSE: We define own namespace prefixes > >> PREFIX("pred", "http://www.w3.org/2007/rif-builtin-predicates#"). > >> PREFIX("func", "http://www.w3.org/2007/rif-builtin-functions#"). > >> for RIF builtin functions and predicates > >> > >> > >> 3) The handling of errors seems not to be anything we need to discuss > >> over again. > >> > >> 4) Additionally, I suggest to introduce: > >> > >> PREFIXDef ::= ' PREFIX(' PNAME_LN , STRING ') .' > >> > >> for the prefix definition in the presentation syntax. > >> Whether this expands to Qnames or entitties in the actual XMLificaiton > >> is a separate issues [8,9] and not important for stabilitzing DTB, it > >> seems. In doubt, I am with Michael here [9] and suggest that in a > >> translator to XML PREFIXDef translates to an ENTITY definition... but > >> that's an implementation detail anyways, one could likewise simply > >> expand all CURIEs in the XML.... The only problem with that is that if > >> you want to translate *BACK* to presentation syntax again, you will end > >> up with something ugly, if we go for option b) on 1) above. > >> > >> > >> Axel > >> > >> > >> > >> [1] http://lists.w3.org/Archives/Public/public-rif-wg/2008Apr/0194.html > >> > >> [2] http://lists.w3.org/Archives/Public/public-rif-wg/2008May/0015.html > >> > >> [3] http://lists.w3.org/Archives/Public/public-rif-wg/2008Apr/0203.html > >> > >> [4] http://lists.w3.org/Archives/Public/public-rif-wg/2008May/0019.html > >> > >> [5] http://lists.w3.org/Archives/Public/public-rif-wg/2008May/0005.html > >> > >> [6] http://lists.w3.org/Archives/Public/public-rif-wg/2008May/0008.html > >> > >> [7] http://lists.w3.org/Archives/Public/public-rif-wg/2008Apr/0196.html > >> > >> [8] http://lists.w3.org/Archives/Public/public-rif-wg/2008May/0011.html > >> and following thread. > >> > >> [9] http://lists.w3.org/Archives/Public/public-rif-wg/2008May/0027.html > >> > >> > > > > > -- > Dr. Axel Polleres, Digital Enterprise Research Institute (DERI) > email: axel.polleres@deri.org url: http://www.polleres.net/ > > rdfs:Resource owl:differentFrom xsd:anyURI . >
Received on Tuesday, 6 May 2008 12:12:14 UTC