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Lang and dt in the graph. Was: Dumb SPARQL query problem

From: Tim Berners-Lee <timbl@w3.org>
Date: Sun, 1 Dec 2013 07:25:12 -0500
Cc: public-lod@w3.org
Message-Id: <18217F38-A9C0-4C11-8690-44BFAB746FAA@w3.org>
To: Andy Seaborne <andy.seaborne@epimorphics.com>

On 2013-11 -23, at 12:21, Andy Seaborne wrote:

> 
> 
> On 23/11/13 17:01, David Booth wrote:
>> [...]
>> This would have been fixed if the RDF model had been changed to
>> represent the language tag as an additional triple, but whether this
>> would have been a net benefit to the community is still an open
>> question, as it would add the complexity of additional triples.
> 
> Different.  Maybe better, maybe worse.
> 
> 
> Do you want all your "abc" to be the same language?
> 
>   "abc" rdf:lang "en" .
> 
> or multiple languages:
> 
>   "abc" rdf:lang "cy" .
>   "abc" rdf:lang "en" .
> 
> 
> ?
> 
> Unlikely - so it's bnode time ...
> 
> :x :p [ rdf:value "abc" ; rdf:lang "en" ] .

The nice thing about this in a n3rules-like system (where FILTER and WHERE clauses are not distinct and some properties are just builtins)   is that rdf:value and rdf:lang can be made builtins so a datatypes literal can behave just like a bnode with two properties if you want to.

But I have always preferred it with not 2 extra triples, just one:

	:x  :p [ lang:en "cat" ]

which allows you also to write things like

	:x :p  [ lang:en "cat"] , [ lang:fr "chat" ].

or if you use the  ^  back-path syntax of N3 (which was not taken up in turtle),

	:x :p "cat"^lang:en,  "chat"^lang:fr .

You can do the same with datatypes:

	:x :q   "2013-11-25"^xsd:date .

instead of

	:x :q   "2013-11-25"^xsd:date .


I suggested way back these properties as a way of putting the info into the graph 
but my suggestion was not adopted.  I think it would have made the model
more complete which would have been a good think, though 
SPARQL would need to have language-independent query matching as a  special case -- but
it does now too really.
  
(These are interpretation properties.  I must really update 
http://www.w3.org/DesignIssues/InterpretationProperties.html)

Units are fun as properties too. http://www.w3.org/2007/ont/unit

Tim

> 
> 	Andy
> 
Received on Sunday, 1 December 2013 12:25:13 UTC

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