- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Tue, 25 Jan 2005 18:52:54 +0000
- To: Alberto Reggiori <alberto@asemantics.com>
- CC: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Alberto Reggiori wrote: > > hi all, > > while looking at the current editor's draft about CONSTRUCT > > http://www.w3.org/2001/sw/DataAccess/rq23/#prod-sparql-ConstructPattern > > it seems the production allows to have "blocks" by using braces, in > addition to simple sequences of triple-patterns: > > [13] ConstructPattern ::= ConstructElement+ > [14] ConstructElement ::= TriplePattern | '{' ConstructPattern '}' > > while I added simple TriplePattern and '{' ConstructPattern '}' blocks > to our CONSTRUCT DAWG testbed, I am not so convinced we need blocks at > that level - which might unnecessarily complicate the whole parsing and > processing. > > Is there any particular reason to have the '{' ConstructPattern '}' > block syntax, a part being more homogenous with the rest of the > grammar? (perhaps if we would have bNodes _:foo scoped to the block it > might make some sense) > > Why not simplify ConstructPattern to: > > [13] ConstructPattern ::= TriplePattern+ > > > ? > > Any explanation is appreciated > > thanks > > Alberto > > - > Alberto Reggiori, Senior Partner, R&D @Semantics S.R.L. > www.asemantics.com Milan Office > Alberto: The CONSTRUCT productions need some work: 1/ As you point out, no {} are necessary. 2/ The tokens are slightly different (bNodes in CONSTRUCT) I thought of using the term "template" for the contents of CONSTRUCT and plan on having separate productions for such templates. Roughly this is your modified [13] except a triple pattern can also have "_:a" (and this is removed from the plain triple pattern - legal in XML 1.1 as a qname but it confuses people in RDF). The grammar should get updated this week - there are a number of things to do. Andy
Received on Tuesday, 25 January 2005 18:53:43 UTC