- From: Fred Zemke <fred.zemke@oracle.com>
- Date: Tue, 06 Jun 2006 18:10:51 +0000
- 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 brackets. 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. Fred
Received on Tuesday, 6 June 2006 19:03:42 UTC