- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Tue, 22 Nov 2011 23:00:01 +0000
- To: Alex Hall <alexhall@revelytix.com>
- Cc: Andy Seaborne <andy.seaborne@epimorphics.com>, RDF-WG <public-rdf-wg@w3.org>
On 22 Nov 2011, at 21:09, Alex Hall wrote: >> The current situation around escaping in RDF is already a glorious mess. Let me illustrate this with an example, let's say querying DBpedia: > > What exactly are these strings/IRIs/prefixed names intended to represent? Terms in a SPARQL query? Terms in a Turtle document? SPARQL. > If you're talking about terms in a Turtle document, some of your examples below don't line up with my reading of the Turtle editor's draft. The examples are actual data from DBpedia. >> // Special characters in literals…? >> >> "Éire" – Works! >> "\u00C9ire" - Works! >> >> // Ok, easy enough. What about IRIs? >> >> <http://dbpedia.org/resource/Éire> – Doesn't work :-( > > Why not? É is a legal IRI character in Turtle. Because it's not an actual DBpedia IRI. DBpedia uses %C3%89, not É. >> <http://dbpedia.org/resource/\u00C9ire> – Doesn't work :-( > > Why not? Turtle allows Unicode escapes in IRIs. See above. >> <http://dbpedia.org/resource/%C3%89ire> – Works! > > Works in the sense that it's a legal IRI, but it's the IRI "http://dbpedia.org/resource/%C3%89ire" Yes – which is an actual DBpedia IRI. > which is not the same as the IRI "http://dbpedia.org/resource/Éire" Which is not an actual DBpedia IRI. > (although an application might normalize it as such). That would violate several specs. >> // Strange… So what about prefixed names? >> >> dbpedia:%C3%89ire – Doesn't work :-( > > I wouldn't expect that to work. I don't know of any format that supports percent-encoding with prefixed names. This example would work in RDFa. >> dbpedia:Éire – Doesn't work :-( > > Why not? É is a legal pname character in Turtle. Because in DBpedia uses %C3%89, not É. >> dbpedia:\u00C9ire – Doesn't work :-( >> dbpedia:\u00C3\u0089ire – Doesn't work :-( > > I REALLY wouldn't expect this one to work. Is there any format where "\u00C3\u0089" will produce "É"? Hopefully not! The point is the next sentence. >> Now the proposal adds to that mess by adding *another* way of writing things differently with *no* increase in expressivity. (The results for all the cases above are unaffected by the proposal – the DBpedia IRI simply cannot be written as a prefixed name.) … > I should also point out that the Turtle editor's draft DOES allow Unicode escapes in prefixed names, so it's removing them that would be a change. So the editors did a change from the Team Submission without WG consensus. Best, Richard
Received on Tuesday, 22 November 2011 23:00:40 UTC