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Re: future of SKOS constraint S12 in an RDF 1.1 world?

From: Peter Ansell <ansell.peter@gmail.com>
Date: Thu, 3 May 2012 15:18:40 +1000
Message-ID: <CAGYFOCQK5xJyFkPPdgqiw+gn9Avw7S1MHG_AqWvWvx8yNXZm=g@mail.gmail.com>
To: Johan De Smedt <johan.de-smedt@tenforce.com>
Cc: Bob DuCharme <bob@snee.com>, public-esw-thes@w3.org
It seems that way. However, it is a little worrying that the following
note was added, as it seems to imply that the IRI will have no formal
definition and hence it may not be uniformly supported by RDFS or
other reasoners when used in range definitions. This may be something
that needs to be brought up on the public-rdf-comments mailing list
for clarification.

"NOTE: Language-tagged strings have the datatype IRI rdf:langString.
No datatype is formally defined for this IRI because the definition of
datatypes does not accommodate language tags."

On 3 May 2012 14:49, Johan De Smedt <johan.de-smedt@tenforce.com> wrote:
> Thanks Peter,
>
> So a change to make SKOS RDF-1.1 aligned would need labels to have as a range rdf:langString (or the union of xsd:string and rdf:langString).
>
> Kind Regards,
>
> Johan De Smedt
>> -----Original Message-----
>> From: Peter Ansell [mailto:ansell.peter@gmail.com]
>> Sent: Thursday, 03 May, 2012 06:29
>> To: Johan De Smedt
>> Cc: Bob DuCharme; public-esw-thes@w3.org
>> Subject: Re: future of SKOS constraint S12 in an RDF 1.1 world?
>>
>> Supporting language tags in RDF-1.1 is one downside of throwing away
>> the concept of a plain literal. The issue seems to be closed in the
>> workgroup [1] with the resolution as documented on [2].
>>
>> [1] http://www.w3.org/2011/rdf-wg/track/issues/71
>> [2] http://lists.w3.org/Archives/Public/public-rdf-wg/2011Sep/0083.html
>>
>> On 3 May 2012 14:08, Johan De Smedt <johan.de-smedt@tenforce.com> wrote:
>> > Hi Peter, Bob,
>> >
>> >
>> >
>> > If a change is needed, would rdf:PlainLiteral
>> > (http://www.w3.org/TR/rdf-plain-literal/) be a candidate to support language
>> > tags?
>> >
>> >
>> >
>> > Kind Regards,
>> >
>> >
>> >
>> > Johan De Smedt
>> >
>> >> -----Original Message-----
>> >
>> >> From: Peter Ansell [mailto:ansell.peter@gmail.com]
>> >
>> >> Sent: Thursday, 03 May, 2012 01:01
>> >
>> >> To: Bob DuCharme
>> >
>> >> Cc: public-esw-thes@w3.org
>> >
>> >> Subject: Re: future of SKOS constraint S12 in an RDF 1.1 world?
>> >
>> >>
>> >
>> >> Hi Bob,
>> >
>> >>
>> >
>> >> That is unusual that the SKOS spec did not allow for xsd:string
>> >
>> >> literals at the time. People have been typing string literals as
>> >
>> >> xsd:string since well before SKOS came around.
>> >
>> >>
>> >
>> >> If one interprets the SKOS spec liberally with respect to RDF-1.1 then
>> >
>> >> it would make sense to simply read "plain literals" as "xsd:string
>> >
>> >> typed literals". The basis for this pragmatic change would be that
>> >
>> >> "plain literals" will have no meaning soon, even if RDF-1.0 documents
>> >
>> >> are still going to be readable by RDF-1.1 parsers.
>> >
>> >>
>> >
>> >> Is it a big issue to change the SKOS spec?
>> >
>> >>
>> >
>> >> Cheers,
>> >
>> >>
>> >
>> >> Peter
>> >
>> >>
>> >
>> >> On 2 May 2012 23:00, Bob DuCharme <bob@snee.com> wrote:
>> >
>> >> > At http://www.w3.org/TR/2009/REC-skos-reference-20090818/#L1329 the SKOS
>> >
>> >> > spec says the following for constraint S12: "The rdfs:range of each of
>> >
>> >> > skos:prefLabel, skos:altLabel and skos:hiddenLabel is the class of RDF
>> >> > plain
>> >
>> >> > literals." As I understand this, the triple {:myConcept1 skos:prefLabel
>> >> > "my
>> >
>> >> > home page"^^xsd:string} violates this constraint, but wouldn't if the
>> >> > object
>> >
>> >> > was just "my home page".
>> >
>> >> >
>> >
>> >> > At http://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal, the RDF
>> >> > 1.1
>> >
>> >> > Concepts and Abstract Syntax says "This section is a major departure
>> >> > from
>> >
>> >> > RDF 2004 as simple literals are now treated as syntactic sugar for
>> >
>> >> > xsd:string typed literals."
>> >
>> >> >
>> >
>> >> > If simple literals are treated as xsd:string typed literals, what would
>> >> > this
>> >
>> >> > mean for constraint S12?
>> >
>> >> >
>> >
>> >> > thanks,
>> >
>> >> >
>> >
>> >> > Bob
>> >
>> >> >
>> >
>> >> >
>> >
>> >> >
>> >
>> >> >
>
Received on Thursday, 3 May 2012 05:19:10 UTC

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