- From: Dan Connolly <connolly@w3.org>
- Date: Thu, 14 Jun 2001 17:46:49 -0500
- To: guha@alpiri.com, Brian McBride <bwm@hplb.hpl.hp.com>, Sergey Melnik <melnik@db.stanford.edu>, rdf core <w3c-rdfcore-wg@w3.org>
Dan Connolly wrote: > > "R.V.Guha" wrote: > > > > Sorry for being slow, but on reconstruction, how does > > one disambiguate between > > > > <rdf:Description rdf:ID="#foo"/> > > > > and > > > > <rdf:Description rdf:about="##foo"/> > > One doesn't; #foo isn't an XML ID (they start > with letter), nor is ##foo a URI reference (no URI > reference has two #'s in it). Now that I think about it... that reminds me of a nasty hairball that I thought we could avoid for a while; but it comes up if we're getting serious about saying that rdf:ID="foo" is the same as rdf:about="#foo": XML IDs can use non-ASCII characters, but URI references cannot. I put at test case at http://www.w3.org/2000/10/rdf-tests/rdfms-difference-between-ID-and-about/nonASCIIid.rdf http://www.w3.org/2000/10/rdf-tests/rdfms-difference-between-ID-and-about/nonASCIIid.nt Here's a copy: ============== <!-- non-ascii characters in IDs... cf http://www.w3.org/TR/charmod/#sec-URIs http://www.w3.org/TR/2001/WD-charmod-20010126/#sec-URIs --> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" > <rdf:Description rdf:ID="Dürst"> <rdf:value>abc</rdf:value> </rdf:Description> <rdf:Description rdf:about="#D%C3%BCrst"> <rdf:value>abc</rdf:value> </rdf:Description> </rdf:RDF> ============== cwm gets it wrong, but the right answer, I suggest, has just one triple: ========= <http://www.w3.org/2000/10/rdf-tests/rdfms-difference-between-ID-and-about/nonASCIIid.rdf#D%C3%BCrst> <http://www.w3.org/1999/02/22-rdf-syntax-ns#value> "abc" . ========= This follows, indirectly, from: [[[ Note: Although non-ASCII characters in URIs are not allowed by [URI], [XML] specifies a convention to avoid unnecessary incompatibilities in extended URI syntax. Implementors of RDF are encouraged to avoid further incompatibility and use the XML convention for system identifiers. Namely, that a non-ASCII character in a URI be represented in UTF-8 as one or more bytes, and then these bytes be escaped with the URI escaping mechanism (i.e., by converting each byte to %HH, where HH is the hexadecimal notation of the byte value). ]]] -- Resource Description Framework (RDF) Model and Syntax Specification http://www.w3.org/TR/REC-rdf-syntax/ Wed, 24 Feb 1999 14:45:07 GMT -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Thursday, 14 June 2001 18:47:56 UTC