W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > January to March 2007

Comments on RQ25

From: Orri Erling <erling@xs4all.nl>
Date: Fri, 26 Jan 2007 11:23:23 +0100
To: <public-rdf-dawg@w3.org>
Message-ID: <DIEBIJHLANKBNNOKDPCCIENLICAA.erling@xs4all.nl>






SPARQL RQ 25 Notes


Here are some initial comments.

While reading the document, I found the following typos:


dervived
equivilent
displacment


At the start of 4.4, readability could be better.  The casual reader gets
confused about basic and group graph patterns.   Since I had not myself
written our  SPARQL parser, I had to go to the grammar to see the point.

It should be said somewhere at the start that:

Basic graph pattern consists  of zero or more triple patterns.  For the
pattern to match, all vvvariables and blank node  labels must be bound so
that triples corresponding to the bindings exist in the data.  If a basic
graph pattern is empty,  it has one solution and produces no bindings.

Also, the point about the scope of a blank node label should be reiterated a
few times in the text, something like:"

{{_:b1 foaf:name "Alice"} {_:b1 foaf:mbox ?box}}

is not the same as

{_:b1 foaf:name "Alice" . _:b1 foaf:mbox ?box}

because the scope of a blank node label does not go outside of a basic graph
pattern.





Orri
Received on Friday, 26 January 2007 08:56:25 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:35 GMT