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specifying extended valueTesting without reference to implementations

From: Dan Connolly <connolly@w3.org>
Date: Fri, 15 Apr 2005 12:20:56 -0500
To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Message-Id: <1113585657.4891.502.camel@localhost>

I see
"Implementations may provide custom extended value testing operations,
for example, for specialized datatypes."
 -- http://www.w3.org/2001/sw/DataAccess/rq23/#extensionFunctions
    $Revision: 1.300 $ of $Date: 2005/04/14 11:43:04 $

That looks suspiciously like an rfc2119 "may". If it is,
we need a definition of "Implementation". If it's not,
some other part of the spec needs to say normatively what
is being said informatively here.

I have asked before that we...
specify the language without reference to implementation ...
22 Dec 2004

The specification guidelines have some good material on this sort
of stuff...


Specifically, I suggest:

- in 2.1 "The example below shows a SPARQL query" should have a forward
reference to the definition of "SPARQL query" in section A. SPARQL
Grammar. (the "SPARQL Grammar" section shouldn't be called an
appendix. It's integral to the spec).

- add term, say "Core SPARQL query" or maybe two terms...
"Extended SPARQL query" too. Hmm... these should be terms in
the abstract syntax (my first clue was that they are
distinguished by fully-expanded URIs, not URI references).
Where is the abstract syntax for expressions? I don't see
any formal definitions that explain how FILTER works.
Oh... Definition: Value Constraint. Could be more
explicit/elaborate, but I get the gist. 

 An extended SPARQL query is a SPARQL query whose
 value constraints involve calls to functions
 identified by URIs other than the URIs for
 fn:compare, fn:not, and fn:matches.

 A Core SPARQL query is a SPARQL query that is
 not an extended SPARQL query.

Hmm... in order to tell an extended SPARQL
query from a core sparql query, you need the
base URI in there somehow.

What's the term in the abstract syntax for the
whole thing, ala SPARQL query in the concrete syntax?

I was trying to provide specific replacement
text for ""Implementations may provide custom extended
value testing operations..." but I'm having trouble,
so I think I'll just stop and send these questions/comments

Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Friday, 15 April 2005 17:20:59 UTC

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