Comments on June 14th release

I have posted a couple of issues regarding what I felt were less than  
clear areas of the SPARQL spec.

This is a comment on the nature of the language itself.

1. Overall, it is a nice addition to the RDF universe. It is  
particularly relevant in industry because of prior familiarity with  
SQL. (It is a big bonus to be able to tell my boss that SPARQL=SQL  
for RDF; even it is not quite accurate:)

2. I am implementing the spec as an exercise; in a white room  
environment (i.e., no JENA etc.)

3. Some of the features of the language I will almost certainly not  
be implementing are:
  REDUCE and OFFSET. The first because I can see no need for it; and  
the second because it is tacky.

  (There are features that I will not implement at this time; mainly  
all the stuff about GRAPH -- simply because I do not need it.)

4. Having an algebraic semantics is potentially very helpful.  
However, there are a number of corners skipped in the current  
presentation:
  (a) the transformation from abstract syntax to algebra (this is  
being fixed?)
  (b) the specification of the interpretation of ORDER BY

5. A major issue for me is the apparent confusion about blank nodes.  
This is not dealt with fully in the spec.
  For example, can a blank node in the query match a non-blank node  
in the graph? (I believe yes; but I have not done enough homework to  
prove it)

6. It would be *nice* if there were standard built-ins around  
collection and container membership. But perhaps this is my ignorance?

I hope that this comment is helpful

Frank McCabe