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Re: getting language tags out of the fundamental model (ISSUE-12)

From: Pat Hayes <phayes@ihmc.us>
Date: Wed, 1 Jun 2011 09:07:48 -0500
Cc: Andy Seaborne <andy.seaborne@epimorphics.com>, public-rdf-wg@w3.org
Message-Id: <252011C9-2D30-44B8-A363-AC61D966325A@ihmc.us>
To: Ivan Herman <ivan@w3.org>

On Jun 1, 2011, at 1:43 AM, Ivan Herman wrote:

> 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.

I hope that is what Andy was saying, because this is what I was saying also :-)

> 
> And that is quite a compelling argument against rdf:Lang-{langname} to me, I must admit

And to me.

Pat

> 
> Ivan
> 
> 
>> 
>> 	Andy
>> 
>> 
>>>> 
>>>> Regards,
>>>> Dave
>>>> 
>>>> 
>>>> 
>>>>> 
>>>>> Andy
>>>>> 
>>>> 
>>> 
>> 
> 
> 
> ----
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
> PGP Key: http://www.ivan-herman.net/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
> 
> 
> 
> 
> 
> 
> 

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Received on Wednesday, 1 June 2011 14:08:19 GMT

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