Sparql grammar questions/comments

I've been building a simple parser/translator from sparql to RDF Gateway's
query language (in our scripting language). It's been mostly straight
forward except around expressions. Things seem a bit murky there in the
grammar. For example things like this are seemingly allowed:

	... OPTIONAL AND ?a>2

or 
	
	... SOURCE ?src AND ?x=='huh?'

which I can't translate because I don't really know what they mean.

Also it seems that an expression could just be:

	AND ?x

Is that intended to be a valid expression?

What about:

	AND ?a eq ?b eq 'dog'

Would you interpret that as (?a eq ?b) eq 'dog'? or (?a eq ?b) && (?b eq
'dog')?

I guess I'm wondering if I should just hold off on playing with expressions
for a bit (i.e. the grammar isn't really ready yet for close inspection).
Or...?

Also, though I guess you haven't published it for comments yet, two thumbs
up anyway for the initial protocol draft
(http://monkeyfist.com/kendall/sparql-protocol/). I'm so happy to see that
the protocol will include update capabilities - makes it hugely more useful.


Thanks,

Geoff Chappell

Received on Saturday, 13 November 2004 03:12:51 UTC