- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Fri, 17 Dec 2004 20:39:34 +0000
- To: Dan Connolly <connolly@w3.org>
- Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Dan Connolly wrote: > On Fri, 2004-12-17 at 17:56 +0000, Seaborne, Andy wrote: > >>1/ Character sets >> >>I propose SPARQL queries use UTF-8 > > > SPARQL queries are sequences of characters; how they're > encoded is a protocol issue, right? Yes, noting that Content-Type does not apply to the request URI. And RFC 2396 is a bit vague on the matter as to the charset of what is being encoded. Literals can contain any character from UTF and there is no distinguishing markers. I think this means we have to choose one. As currently stated, the SPARQL query language syntax uses XML 1.1 qnames which includes a wide range of characters in UTF. What does IRI say? Any suggestions from that direction? > > i.e. under the "chair expects editor to respond to each > proposal to change that editor's spec; others in the > WG are welcome to advise; chair steps in if consensus > does not emerge" sort of game, I'm watching for Kendall's response. > > >>This allows multi (natural) language queries. >> >>HTTP GET will have to encoded as usual - we do need to decide the string being >>encoded. >> >>In HTTP POST, Content-Type applies to the entity body. >>A request sent by HTTP POST may use Content-Type to change the charset. >> >>Experiences with declaring the charset in the content show >>this to be very error prone: >> >> a/ it may disagree with the HTTP header >> >> b/ once opened in one fashion, say the default platform charset, >> it can be hard to reopen in another fashion: the underlying >> stream maybe buffered. >> >>Aside: as the syntax currently stands (a keyword must be first), it is possible >>to snoop and tell the difference between UTF-8 and UTF-16. >> >> >>2/ We will need a URI for SPARQL > > > I'm not so sure. > > My implementation experience suggests we choose > a URI for the relationship between > a KB and a SPARQL query for that KB. In Joseki, there is a URI for the language and this is associated with a KB/service by a property. This fits with the "query-lang=" parameter but if you wish to define that as the relationship between SPARQL and any KB then fine. Which ever, "SPARQL" is a concept so we should give it a URI so people can reference it anyway. > > >>Suggestions: >>http://www.w3.org/2001/sw/DataAccess/SPARQL >> >>(We might want to allow for future revisions but I assume a new WG would have a >>new URI itself so versioning isn't needed here). >> >> >>3/ Relative URIs >> >>Queries would need a base URI to resolve any relative URIs. > > > would... subjunctive... > > is this an issue in the current draft? > > I can't tell from the grammar... > http://www.w3.org/2001/sw/DataAccess/rq23/#term-sparql-URI > $Revision: 1.160 $ of $Date: 2004/12/17 18:16:17 $ > > I suggest uriRef as the terminal name, if relative URI references > are, by intent, allowed. > > Hmm... we don't currently specify how the syntactic productions > relate to the formal definitions, do we? > > > >>We can either say "no relative URIs" (that might makes the tests harder if we >>follow the style of the manifests in using relative URIs). >> >>For the protocol, "query-uri=" is a natural default base but there isn't a >>natural one in all situations like local queries from a program or one sent as >>plain "query=" >> >>I suggest a BASE clause in the QL that must be before PREFIXes. It takes a >>single, <> quoted URI. It is not required in every query. > > > Seems reasonable. > > >> Andy > >
Received on Friday, 17 December 2004 20:40:01 UTC