- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Thu, 04 Aug 2005 11:55:33 +0100
- To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Aug/0038 Walid Maalej wrote: > Dear RDF Data Access Working Group Members, > > In the last working draft of the 21st. of July 2005, changes have been done > concerning the definition of the variable names within a SPARQL query. > The syntax is specified under > http://www.w3.org/TR/rdf-sparql-query/#rVARNAME . > I'm wondering if there is any reason not to allow the underscore "_" at the > Beginning of a variable name from the grammar point of view. > This could be very useful for application that build SPARQL queries > automatically and call the variables like the RDF:ID of the searched > resource. Allowing "_" as the first character of a VARNAME does not affect any approved tests and does not break the grammar in any way. I have added it. [Info: "_" is treated specially in teh grammar because it can't appear as the start of a qname prefix in SPARQL because that is a blank node]. To be tidy, I defined: NCCHAR1p -- XML NCCHAR1 without "-" for prefixes (used to be SPARQL NCCHAR1) NCCHAR1 -- "NCCHAR1p | '_'" -- now the same as XML NCCHAR1 Used NCCHAR1 where "NCCHAR1p | '_'" would appear. > > Let's suppose we have the following data > <http://example.org/book1> <http://properties.com/_title> "SPARQL Tutorial". > > A Generated query could look like: > > PREFIX exp: <http://example.org/> > PREFIX pro: <http://properties.com/> > SELECT $_title > WHERE { exp:book1 pro:_title $title } > > In general, SPARQL based application developers should not care about > calling the variables. It should be possible to just take over the RDF > Property ID with a "?" as a prefix. Thus, I think that, the syntax of NCNAME > http://www.w3.org/TR/rdf-sparql-query/rNCNAME should be equal to that of > variable names. NCNAME includes "-" and "." which do not commonly appear in variables names and "-" is used for unary and binary minus. I don't think we could do this. > > I would be very glad and thankful for your considerations and for any > explanations or remarks. > > Best Regards -------- While clearing up, I found that [37] GraphNode was an unused rule so I removed it. -------- When reviewed and approved by the WG, I will reply to Walid on the comments list Andy
Received on Thursday, 4 August 2005 10:56:41 UTC