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

* Andy Seaborne <andy@seaborne.org> [2015-10-09 15:50+0100]
> From memory (and I can't recall who was the initial advocate), the
> case for ':' is that it occurs naturally in some existing data,

I believe it was Gavin Carothers asserting that Facebook data had ':'s
in it everywhere. As Andy said, the motivation was not for new data
(we may have persuaded authors to use "\\:" per
<http://www.w3.org/TR/turtle/#grammar-production-PN_LOCAL_ESC>) but a
pre-existing deployment.


> 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.

It would make it a bit more convenient to write ":"-y stuff at the
cost of preventing future uses of nth ":"s for some other parser
behavior.


> 	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 .
> >"
> >
> >>>
> >>>>
> >>>
> >>
> >>
> >
> 

-- 
-ericP

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Received on Friday, 9 October 2015 15:29:33 UTC