- From: <Patrick.Stickler@nokia.com>
- Date: Wed, 7 Nov 2001 15:04:18 +0200
- To: bwm@hplb.hpl.hp.com
- Cc: w3c-rdfcore-wg@w3c.org
> I presume from the above we are considering the P option.
> What the query would
> actually return would be better represented as:
>
> <#foo> <#intProperty> _:lit:"0x12" .
>
> You are right that there is not sufficient information here
> to deduce what
> "0x12" means, but one could then query for the rdf:type
> property of _:lit:"0x12"
> which would return:
>
> _:lit:"0x12" <rdf:type> <#hexProperty> .
>
> And that is sufficient. Eh? :)
Yes. I was actually not considering the P option, but
fearing that the response would have been:
<#foo> <#intProperty> "0x12" .
I.e., no way to get to
_:lit:"0x12" <rdf:type> <#hexProperty> .
As for the P option, just how does one then get the lexical
form from the label? Is the label is a new construct of the
RDF Graph itself? Or do I have to parse the nodeID to get it?
If I have to parse the nodeID to get it, and if the goal
of the label is to compress the graph with regards to
literals, then why not just use a URV. Very tight, and portable
beyond the RDF space.
I.e.
<#foo> <#intProperty> <xxx:hexInteger:0x12> .
Done. No need for two separate queries. Got rid of even
one more arc. Data type tightly bound to lexical form.
Doesn't get in the way of inferred bindings, etc.
Eh?
> Now querying for representation properties of _:anon we get
>
> _:anon <#hexInteger> "0x12" .
>
> which would seem to be sufficient.
The problem I have with this approach is that it mixes
the datatype classes with property classes -- maybe that's
not such a big deal, but something in my gut doesn't like
it.
I think it is because I'm expecting to get
_:anon rdf:value "0x12" .
_:anon rdf:type <#hexInteger> .
The fact that the type is "hidden" in the property seems
less clean to me. Of course, that's just a subjective
impression, but ...
I can see that both the P and S approaches are trying to
reduce the number of arcs/nodes in the graph and make the
relationship between literal and type tighter, but both
seem equally successful and unsuccessful. P makes the type
relation clear but "hides" the lexical form in a label
that I can't see how I get at in the graph apart from
extracting it from the nodeID. S makes the lexical form
clear but hides the type semantics behind property semantics,
which could be confusing. Both shrink the graph the same
amount.
The X approach shrinks the graph even more, and apart
from having to parse the URV, keeps the type and lexical
form explicit. So I guess I see it as being better, but
of course, I'm grossly biased ;-)
> Finally, thanks again for taking the trouble to provide a
> concrete example. It
> communicated so much better to me, and possibly others in the
> WG, what you meant.
You're welcome.
Cheers,
Patrick
Received on Wednesday, 7 November 2001 08:04:26 UTC