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Re: CURIEs and blank nodes (Test #140)

From: Dan Connolly <connolly@w3.org>
Date: Tue, 09 Feb 2010 09:59:23 -0600
To: Ivan Herman <ivan@w3.org>
Cc: public-rdf-in-xhtml-tf <public-rdf-in-xhtml-tf@w3.org>
Message-ID: <1265731163.3812.1009.camel@pav.lan>
On Tue, 2010-02-09 at 13:06 +0100, Ivan Herman wrote:
> 
> On 2010-2-9 03:16 , Dan Connolly wrote:
> > My code fails Test #140, so I'm checking the spec
> > to find out why.
> > 
> > In section 7. CURIE Syntax Definition
> >   http://www.w3.org/TR/rdfa-syntax/#s_curies
> > 
> > we find:
> > 
> >   A CURIE is a representation of a full URI.
> > 
> > That contradicts other parts of the spec. I suggest
> > making it true by constraining the syntax of CURIEs
> > to exclude the _:foo construct.
> > 
> > The other alternative is to say something like:
> > 
> >  A CURIE is a representation of either an absolute IRI or a blank node.
> 
> I would definitely prefer this one. Excluding the _:xxx would be a
> problem. There are some (albeit rare) cases when explicit reference to
> blank nodes are necessary (eg, if lists are encoded).

I'm not talking about changing RDFa functionality; I'm just
talking about spec terminology. I'm suggesting that _:foo
is allowed and works just like you prefer, but it's not
called a CURIE, but a blankID or some such.

> 
> > 
> > or fudge it a la:
> > 
> >  A CURIE typically represents an absolute URI.
> > 
> 
> I do not have problem with that either.
> 
> > (does the RDFa spec exclude IRIs on purpose? It's somewhat lax about
> > the difference between a URI (which, strictly speaking, is
> > always absolute) and a URI reference (which may be relative). I
> > wonder if it similarly uses URI where the standard term is
> > actually IRI.)
> 
> I guess bringing in the IRI issue may be one of the things that the RDFa
> WG will have to settle for 1.1. That being said, the current RDF spec
> refer to URI-s only,

No, it doesn't. See section 6.4 RDF URI References
http://www.w3.org/TR/rdf-concepts/#section-Graph-URIref
http://www.w3.org/TR/rdf-concepts/#dfn-URI-reference

Note that the 2004 RDF specs use "URI reference" in order to
include #fragments, which were not part of URIs in the URI spec
at the time (RFC2396). The current URI standard (RFC3986)
includes #fragments in URIs.

>  that may be the reason that RDFa sticked to URI-s
> 
> (I must admit that the whole URI/IRI issue never ceases to confuse me. I
> should really take some time diving into this one day...)
> 
> Thanks
> 
> ivan


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
gpg D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Tuesday, 9 February 2010 15:59:25 GMT

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