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Re: Colons in compact URIs, e.G. dbpedia:Category:Bluegrass_music

From: Andy Seaborne <andy@seaborne.org>
Date: Fri, 9 Oct 2015 15:50:01 +0100
To: Tim Berners-Lee <timbl@w3.org>
Cc: SW-forum Web <semantic-web@w3.org>
Message-ID: <5617D419.2010707@seaborne.org>
 From memory (and I can't recall who was the initial advocate), the case 
for ':' is that it occurs naturally in some existing data, typically 
where there are existing identifiers 123:456 so you get 
"http://host/taxonomy/123:456".  Writing full URIs all the time gets to 
be a burden.  And ':' is used in URNs.

Obviously an issue for RDF/XML but that didn't seem to worry anyone much.

I don't see any reason N3 can't evolve to be compatible here.

	Andy

On 09/10/15 13:32, Tim Berners-Lee wrote:
>
> On 2015-10 -09, at 08:00, Andy Seaborne <andy@seaborne.org> wrote:
>
>>
>>
>> On 09/10/15 11:57, Stian Soiland-Reyes wrote:
>>> Excerpts from Michael Brunnbauer's message of 2015-10-09 10:38:33 +0100:
>>>>
>>>> hi all,
>>>>
>>>> is dbpedia:Category:Bluegrass_music a valid compact URI?
>>>> It seems not, because http://www.w3.org/TR/curie/ says:
>>>
>>> No, because it can't be consistently represented as a CURIE in
>>> syntaxes like RDF/XML or Turtle. It could still be valid in some syntaxes
>>> like JSON-LD or RDFa.
>>
>> Colons are legal without escaping in the local part in Turtle (and SPARQL 1.1)
>>
>> [168s] 	PN_LOCAL 	::=
>>   	(PN_CHARS_U | ':' | [0-9] | PLX)
>>         ((PN_CHARS | '.' | ':' | PLX)* (PN_CHARS | ':' | PLX))?
>>
>> 	Andy
>>
>
> Another way in which Turtle has ended up arbitrarily different from N3 it seems.	:-(
> You cannot use a colon in N3.   cwm for example rejects it.
> I would not recommend you use it.
>
> $ echo ' :x a :Category:Bluegrass_music . ' | cwm
>
> Bad syntax (expected '.' or '}' or ']' at end of statement) at ^ in:
> " :x a :Category^:Bluegrass_music .
> "
>
>>>
>>>>
>>>
>>
>>
>
Received on Friday, 9 October 2015 14:50:31 UTC

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