Comments on 2.1.4 "Syntax for blank nodes" in 6 April 2006 CR

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.


2.1.4 Syntax for blank nodes
The preceding section 2.1.3 "Syntax for variables" says
"Variables in SPARQL have global scope".  Section 2.8.3 "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.

Fred

Received on Thursday, 8 June 2006 23:32:05 UTC