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Re: DTB status (on today's agenda)

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>
Message-ID: <7949.1209737057@ubuhebe>

> 
> 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 GMT

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