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editorial comments on CR dated 6 april 2006

From: Fred Zemke <fred.zemke@oracle.com>
Date: Tue, 06 Jun 2006 18:10:51 +0000
Message-ID: <4485C51E.5080207@oracle.com>
To: public-rdf-dawg@w3.org

Some (hopefully) editorial comments:

2.1.1 Syntax for IRIs
It would be helpful to have examples of the two abbreviated syntaxes.
One might think that abbreviated syntaxes must be written in angle

2.3 Triple patterns
The last sentence of this section says "This definition also
allows blank nodes in the predicate position."  But the
second component of a triple pattern is a member of I union V,
where I is the set of IRIs and V is the set of variables.
Thus it seems that SPARQL blank nodes are not permitted in
the second position.  Also the BNF for Verb says it may be
VarOrIRIref or 'a', so it seems that a SPARQL blank node can not
be a predicate.

2.4 Pattern solutions
The first two sentences in the box use the following terms:
"variable solution", "substitution function", "pattern solution",
and "variable substitution".  How are these terms related?
Taken literally, it says that "a variable solution is a substitution
function" and a "pattern solution is a variable substitution".
Thus the first and second sentence seemingly have nothing to do
with one another. In that case, why is the first sentence, about
"variable solution", found in a box called "Definition: pattern
solution"?  This is very confusing.  The reader is left
suspecting that in fact all four terms are interchangeable.
Furthermore, scanning the rest of the document, one finds that
"variable solution" is never used at all, and the
term "solution" is frequently used without qualification (neither
as "variable solution" nor as "pattern solution"). We should use
our terminology consistently.

2.5.1 General framework
Definition of "basic graph pattern E-matching", first bullet
talks about BGP and BGP' being "graph-equivalent".  This term
is not defined; instead "equivalent" is.  we should use our
terminology consitently.

9 Specifying RDF datasets
A graph is specified using an IRI, which can be a QName, but there
are no examples of using a QName to specify a graph.  This would
be helpful.

10.1 solution sequences and result forms
The first formal definition says that a "solution sequence" is
a "list".  Both of these terms imply ordering.  Then the last
sentence in the first box says "The solution sequence from
matching the query pattern is an unordered collection...".  
This is contradictory.  What we probably mean is that "The
solution sequence from matching the query pattern is in an
implementation-dependent order".  

10.1 Solution sequences and result forms
the last sentence in the first box says "The solution sequence
from matching the query pattern is an unordered collection...".
This sentence is not part of the definition
of "solution sequence" so it should be placed outside the box.

10.1 Solution sequence and result forms
It would be helpful if the stages of processing solution sequences
were always mentioned in the same order.  The order is given as
ORDER BY, project, DISTINCT, LIMIT, OFFSET.  The text to be
rearranged is:

a) In the box for the definition of solution sequence modifier
(order modifier should be moved ahead of projection modifier)
b) The arrangement of subsections (10.1.3 ORDER BY should be
moved ahead of 10.1.1 Projection)

A.5 Escape sequences in strings
It says that \U may only be used for Unicode code points in the range
U+10000 through U+10FFFF.  So the first two HEX digits must always be 00?
If so, why not show the syntax as '\U00' HEX HEX HEX HEX HEX HEX ?
A.6 "excape sequences in IRI references" - same comment.

Received on Tuesday, 6 June 2006 19:03:42 UTC

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