- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Mon, 24 Jul 2006 10:03:40 +0100
- To: Fred Zemke <fred.zemke@oracle.com>
- CC: public-rdf-dawg@w3.org
Fred Zemke wrote: > > > > 2.1.4 Syntax for blank nodes > It says "Blank nodes...will take part in the pattern matching". > There are no examples of how pattern matching with SPARQL > blank nodes works. Section 2.5.4 "Basic graph patterns in SPARQL > syntax" gives an example of the syntax only, but does not discuss > the semantics of the example that it presents. Section 2.8.3 > "Blank nodes" and 2.8.4 "RDF collections" show how the abbreviations > are expanded into SPARQL blank nodes, but do not show how the > expanded patterns behave either. This becomes "3.1.4 Syntax for Blank Nodes" in rq24. Section 3 is just about syntax so how blank nodes behaves is dealt with new section "5 Basic Graph Patterns". > > > 2.1.4 Syntax for blank nodes > The preceding section 2.1.3 "Syntax for variables" says > "Variables in SPARQL have global scope". Now section "3.1.3 Syntax for Query Variables" and it is about the ? form. Blank nodes have variable characteristics through entailment. For some forms of entailment, blank nodes can be treated as variables. > Section 2.8.3 "blank nodes" Now "3.1.4 Syntax for Blank Nodes" > says "Blank nodes have labels which are scoped to the query". > It is not clear to me what the difference between the "global scope" > of a variable vs. being "scoped to the query" means in practice. > At any rate, I think it would be good to state the scope of blank > nodes (or what I prefer to call blank node identifiers) > in section 2.1.4, as a parallelism with 2.1.3, and possibly > harmonize the terminology. """ Blank nodes are indicated by either the label form "_:a" or by use of "[ ]". ... Blank node labels are written as "_:a" for a blank node with label "a" and the label is scoped to the basic graph pattern. """ > > Fred > >
Received on Monday, 24 July 2006 09:03:56 UTC