- From: Ivan Herman <ivan@w3.org>
- Date: Wed, 1 Jun 2011 08:43:40 +0200
- To: Andy Seaborne <andy.seaborne@epimorphics.com>
- Cc: public-rdf-wg@w3.org
Andy,
On May 31, 2011, at 19:28 , Andy Seaborne wrote:
>
>>>> Modelling everything at a very fine grained level moves the burden on
>>>> to the application.
>>>>
>>>> c.f. RDF containers and collections.
>>>
>>>
>>> Conditionally, yes. It would only arise when language tags are used.
>>> Most strings do not use language tags.
>
> 1/ We find that there can be very lang-tag intensive datasets. For example, data from Wales.
>
> 2/ Don't we have a new variability to deal with:
>
> <s> skos:altLabel
> [ a rdf:LinguisticExpression;
> rdf:language "bar";
> rdf:value "foo"] .
>
> <s> skos:altLabel "foo" .
>
>
> And
>
> { <s> skos:altLabel ?altLabel }
>
> get us back to same problems of RDF collections and a round trip to get the next step in the information (assuming skolemization).
>
>>> The question is, IMO, whether the benefit of fixing the equivalences
>>> between RDF strings is worth the pain to be experienced by users of
>>> language tags in this context. *Personally* I would rather query the
>>> above pattern than need to guess whether a string is a plain literal
>>> or a language tagged string or an xsd:string.
>
> Not sure it's a guess unless we do nothing. At least they are all a single RDF term that can be queries then inspected.
>
> People here seem to want a datatype for all literals.
>
> If every plain literal now has a datatype, xsd:string or rdf:LangString (or other name), and use LANG knowing that rdf:LangString means use LANG to ask further i.e. Value space of ("foo", "en").
>
> rdf:lang-{langTag} requires dereferencing to get the language (or IRI mangling but maybe some invented a different IRI - no unique names here!)
Just to check my understanding; what you are saying is:
- if one goes along the lines originally proposed by Richard, ie, using rdf:LangString (or some similar name) then any SPARQL query involving a language becomes a bit cleaner because one can use lang(?v) in a FILTER or (in SPARQL 1.1) in an AS; whereas
- if one defines a series of rdf:Lang-{langname} then queries (or applications) will have to fiddle around interpreting the URI-s.
And that is quite a compelling argument against rdf:Lang-{langname} to me, I must admit
Ivan
>
> Andy
>
>
>>>
>>> Regards,
>>> Dave
>>>
>>>
>>>
>>>>
>>>> Andy
>>>>
>>>
>>
>
----
Ivan Herman, W3C Semantic Web Activity Lead
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Received on Wednesday, 1 June 2011 06:41:21 UTC