- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Mon, 25 Jul 2005 12:35:25 +0100
- To: Dan Connolly <connolly@w3.org>
- CC: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Dan Connolly wrote: > A commentor points out in > http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Jul/0042.html > > that we're not explicit about whether section > 6.2.2. "Syntax-Based Normalization" and/or > 6.2.3. "Scheme-Based Normalization" of > http://www.ietf.org/rfc/rfc3986.txt are applied > to base IRIs in SPARQL. Consider this > input data: > > @prefix : <http://example/vocab#>. > > :s1 :p <example://a/b/c/%7Bfoo%7D#xyz>. > :s2 :p <eXAMPLE://a/./b/../b/%63/%7bfoo%7d#xyz>. > > and this query: > > PREFIX : <http://example/vocab#> > PREFIX p1: <eXAMPLE://a/./b/../b/%63/%7bfoo%7d#> > > SELECT ?S WHERE { ?S :p p1:xyz } > > It seems to me that the simplest answer is that no, > nothing gets canonicalized, and the answer is that > ?S binds to :s2 only. > > Then re scheme-based normalization, here's another test: > > @prefix : <http://example/vocab#>. > :s3 :p <http://example.com:80/#abc>. > :s4 :p <http://example.com/#abc>. > :s5 :p <http://example.com/#abc>. > > query: > PREFIX : <http://example/vocab#> > PREFIX p2: <http://example.com:80/#> > > SELECT ?S WHERE { ?S :p p2:abc } > > Let's see what current DawgShows say... > SPARQLer ( http://sparql.org/query.html ) binds to > s2 only in the 1st case and to s3 only in the 2nd case. Yes, that's what I'd expect - SPARQLer will not apply scheme syntax or specific based normalization. Checking the RDF recs (which predate RFC 3896) http://www.w3.org/TR/rdf-concepts/#section-Graph-URIref says: """ Two RDF URI references are equal if and only if they compare as equal, character by character, as Unicode strings. """ > > Likewise the rasqal demo > http://librdf.org/query?language=sparql > > > So I suggest adding those two tests to the test suites, > and clarifying the spec: after > > > They stand for IRIs, either directly, or relative to a base IRI. > > we add > > Relative IRIs are combined with base IRIs as per section > 6.5. Relative IRI References of [19], using only the > basic algorithm in section 5. Reference Resolution > of [rfc3986], without the optional Syntax-Based Normalization > nor Scheme-Based Normalization. Agreed. I suggest adding a link to RDF concepts as well. Andy
Received on Monday, 25 July 2005 11:36:02 UTC