- From: Sandro Hawke <sandro@w3.org>
- Date: Fri, 02 May 2008 10:04:17 -0400
- To: Axel Polleres <axel.polleres@deri.org>
- Cc: debruijn@inf.unibz.it, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
> > Jos de Bruijn wrote: > > > > > > Sandro Hawke wrote: > >>> Let me reiterate (for the third time) my extremely simple compromise > >>> proposal. Here expand(foo) means substitute with the prefix > >>> definition of > >>> foo. > >>> > >>> 1. Standalone occurrence: > >>> foo:bar ---> "expand(foo)bar"^^"http://www.w3.org/2007/rif#iri" > >>> > >>> 2. A ^^-occurrence: > >>> "abc"^^foo:bar ----> "abc"^^"expand(foo)bar" > >> > >> I can live with this, if we don't use "^^". This was the second option > >> in my e-mail, although I accidentally expanded bar as well. > >> > >> The problem with ^^ is that it's very distinctive and is used in other > >> semantic web languages. But in those languages, it's followed by a URI > >> constant not a string constant. So I'd have to object that re-using > >> ^^ with this kind of type difference is too confusing to users. > > > > I thought that in RIF ^^ is also always followed by an IRI constant? > > In those other languages you are speaking about, it is followed by a IRI > in angle brackets or a CURIE: > > N3: http://www.w3.org/TeamSubmission/n3/ > > literal ::= string dtlang > dtlang ::= "@" langcode | "^^" symbol > symbol ::= explicituri | qname > explicituri ::= <[^>]*> > qname ::= /* what we called CURIE */ > > Turtle: http://www.w3.org/TeamSubmission/turtle/ > > literal ::= quotedString ( '@' language )? | datatypeString > | integer | double | decimal | boolean > datatypeString ::= quotedString '^^' resource > resource ::= uriref | qname > uriref ::= '<' relativeURI '>' > qname ::= /* what we called CURIE */ > > > SPARQL: http://www.w3.org/TR/rdf-sparql-query/ > > RDFLiteral ::= String ( LANGTAG | ( '^^' IRIref ) )? > > IRI_REF ::= '<' ([^<>"{}|^`\]-[#x00-#x20])* '>' > > Note: No CURIEs allowed in the Grammar there for the type, although > they use CURIEs in the examples in the spec... actually, that > seems to be a bug in their grammar. > > > > > > I think we should stick with the ^^ in RIF, because its use actually > > generalizes the use in the other semantic Web languages. > > I fully agree that RIF presentation syntax should generalize those > languages, yes. We already defer by putting the langtag in side the > string, BTW. Right, but Michael is adamantly against RIF-PS generalizing those languages. So, I can live with this other approach. No pointy brackets and no ^^. -- Sandro > > Axel > > > Best, Jos > > > >> > >> In my previous e-mail I wrote a^^b as lit(a,b), which seems about > >> right. I'm not sure what we should call "lit". SWI-Prolog calls in > >> "type(b, a)". [1] > >> I suppose the obvious thing is "Const", so the change in the grammar is: > >> > >> Remove: > >> > >> Const ::= '"' UNICODESTRING '"^^' SYMSPACE > >> > >> Add (trying to keep current style): > >> > >> Const ::= 'Const(' '"' UNICODESTRING ',' '"' SYMSPACE '"' ')' > >> > >> Does that work? > >> > >> I'd also consider putting the symspace first (as in SWI-Prolog), because > >> in a sense it's the most-significant part. > >> > >>> If you do not like "..." for the after the ^^-part, use '...' or even > >>> <...>. > >>> But, in the latter case, <...> CANNOT be used as a macro. That is, > >>> > >>> <abc> --X--> "abc"^^rif:iri. > >>> > >>> is a no-no. > >>> > >>> My proposal allows some simple form of context sensitivity, but not the > >>> above <...> macro atrocity (if <...> is also used after the ^^). > >>> I do not see why we need such a macro in the first place, if in most > >>> cases > >>> we will be using foo:bar. > >> > >> I can't think of any reason we need "<" ... ">", but we might. I think > >> we can leave them out until/unless we need them. > >> > >> -- Sandro > >> > >> [1] http://www.swi-prolog.org/packages/rdf2pl.html#sec:3.1 > >> > > > > > -- > 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 Friday, 2 May 2008 14:06:12 UTC