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Re: Turtle - Terse RDF Triple Language updated

From: Richard Cyganiak <richard@cyganiak.de>
Date: Sat, 6 Oct 2007 14:00:37 +0200
Message-Id: <B7081370-CE4F-41DE-B63E-99762F01DD59@cyganiak.de>
Cc: Ivan Herman <ivan@w3.org>, Alan Ruttenberg <alanruttenberg@gmail.com>, Story Henry <henry.story@bblfish.net>, Dave Beckett <dave@dajobe.org>, Michael Schneider <schneid@fzi.de>, semantic-web@w3.org
To: Harry Halpin <hhalpin@ibiblio.org>

Harry,

On 6 Oct 2007, at 12:49, Harry Halpin wrote:
>>>> :Joe   :aunt [ is :Sally;   age 78 ].
>
> So perhaps I just haven't had my morning coffee yet, but what 2  
> triples
> should be generated in Henry's example? :Joe :aunt :Sally, :Sally :age
> 78?

Exactly. There is a desire to use the [ ] nesting syntax not just for  
blank nodes, but also for URI-named nodes. Turtle doesn't make this  
possible at the moment, hence the request for additional syntactic  
sugar, the "is" keyword.

> If that's all you want, then run Turtle+entailment, right?

This misses the point. A Turtle author cannot force Turtle consumers  
to run entailment.

> Regardless, as for features like "=" - yes, of course they are useful.
> However, I think the obvious thing to do is to keep Turtle and N3  
> syntax
> separate, with N3 syntax being a superset of Turtle. So, keep Turtle 1
> to 1 with SPARQL, and then have N3 have things like "=" in it.

I think a derivation from SPARQL is warranted in this case, the  
benefits outweigh the costs. The "is" keyword would remove an awkward  
limitation from Turtle, and increase its appeal over N3, which at the  
moment simply is a more convenient and more consistent RDF syntax  
from an authoring point of view. I'm all in favor of a stable Turtle  
spec, but don't see the point if it makes authoring of RDF harder.

(Another Turtle peeve: It forces me to sometimes write "[] a :Foo"  
and sometimes "[ a :Foo ]", depending on wether the blank node is the  
object of another statement. In N3, I can consistently use the second  
form. I have a hard time understanding why this "feature" was  
introduced in Turtle.)

Also note that Turtle and SPARQL already use divergent syntax for  
identical features -- cf. declaration of prefixes and base URIs.

Richard



>
> However, the first hurdle is clearly getting Turtle stable, which  
> it (at
> least to me) seems more or less.
>
> [1] http://www.w3.org/2000/10/swap/Primer
> [2] http://www.w3.org/TR/rdf-sparql-query/
>> Ivan
>>
>>
>>
>>> -Alan
>>>
>>> On Oct 3, 2007, at 10:36 AM, Story Henry wrote:
>>>
>>>
>>>> :me foaf:knows [ owl:sameAs <http://www.w3.org/People/Connolly/ 
>>>> #me>;
>>>>
>>>>                  a foaf:Person;
>>>>
>>>>                  foaf:name "Dan Connolly" ] .
>>>>
>>>>
>>>> That saves me having to look around the file for the info, and  
>>>> it also
>>>> save me having to type a URL twice, which is more likely to  
>>>> cause a bug.
>>>>
>>>>
>>>> If I don't do that I would have to write
>>>>
>>>>
>>>> :me foaf:knows <http://www.w3.org/People/Connolly/#me>.
>>>>
>>>> <http://www.w3.org/People/Connolly/#me> a foaf:Person;
>>>>
>>>>                                         foaf:name "Dan Connolly"  .
>>>>
>>>>
>>
>>
>
>
> -- 
> 		-harry
>
> Harry Halpin,  University of Edinburgh
> http://www.ibiblio.org/hhalpin 6B522426
>
>
>
Received on Saturday, 6 October 2007 12:01:00 GMT

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