- From: Bijan Parsia <bparsia@cs.manchester.ac.uk>
- Date: Mon, 13 Apr 2009 21:35:36 +0100
- To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
On 13 Apr 2009, at 21:03, Seaborne, Andy wrote:
[snip]
> I am expecting it to capture the AST for a query and it would be
> useful to more formally define the abstract syntax.
There has a been a lot of positive feedback from OWL implementors on
the use of UML to define the abstract syntax...I'm not a huge fan,
myself.
I do wish we had thought to scrap the bespoke Functional Syntax and
instead define things in terms of a DOM/Infoset.
> The grammar has both fine-grained and text-oriented detail as well
> as the abstract syntax so driving the design from picking out key
> grammar rules would be a good start IMHO. The old design was for a
> form of the language that was rather different to what it became.
Yes.
> There is an alternative which is to capture the algebra form in XML
> serialization, rather than the syntax. For machine processing, we
> find the algebra easier to work with than the syntax.
>>
True. How do you find it for authoring?
One thing I would like to avoid is ending up with a fine grained
derivation tree a la XQueryX. XQueryX serves a purpose, but I
personally ran screaming from the room when I delved into it ;)
If I get a few, I'll try to sketch up some schema's for various designs.
Actually, I see no reason not to have XML syntax both for SPARQL
queries and for sparql algebra expressions, following:
http://www.w3.org/TR/rdf-sparql-query/#sparqlQuery
Though I guess the latter is the biggest advance (since it covers a
gap...there's no interoperable, to my knowledge, SPARQL algebra API/
exhange format).
[snip]
>> Manchester doesn't care one way or the other about a triply syntax. I
>> will note that the prior working group did reject a triple syntax
>> (based on N3) for SPARQL queries (though adopting Turtleishness for
>> BGPs).
>
> A different issue. The N3-QL proposal was semantics as well.
Ok, cool.
>> I believe that the debate took place at a Boston F2F with TimBL
>> championing the triply syntax, but I was in other group meetings for
>> those bits, IIRC. Perhaps Andy or Steve recall more (Lee? were you
>> there?)?
>
> Not how it happened as I recall. The N3-QL proposal was one of the
> strawman proposals. Well before Boston. The syntax did change at
> Boston but from ()-triples to {}-patterns - both are text-oriented
> forms.
http://www.w3.org/2001/sw/DataAccess/ftf5-bos.html#item07
I think there was some conflation that I was getting between various
aspects of it...
[snip]
> It was a long time ago,
Indeed.
Cheers,
Bijan.
Received on Monday, 13 April 2009 20:36:16 UTC