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Re: datatypes and MT (#rdfms-graph)

From: Dan Connolly <connolly@w3.org>
Date: Wed, 07 Nov 2001 10:13:23 -0600
Message-ID: <3BE95DA3.662D6C93@w3.org>
To: Pat Hayes <phayes@ai.uwf.edu>
CC: w3c-rdfcore-wg@w3.org
[This message is as much about issue
as anything else...]

Pat Hayes wrote:
> >  > >abstract syntax:
> >>  >       terms:
> >>  >               constants (URIs w/fragids)
> >>  >               string literals
> >>  >               bnodes (existentially quantified variables)
> >>  >       statement:
> >>  >               term term term.
> >>
> >>  We've already gone into why this simple a syntax does not work.
> >
> >Really? pointer? example?
> It's in the archive somewhere.

OK, I'm aware there has been discussion along those lines;
I haven't been convinced by it.

I thought you were suggesting that the WG had made a decision
along those lines.

> First, having literals on arcs doesn't
> make sense.

Er... do you mean you don't find it appealing or intuitive,
or that it conflicts with something in a technical sense?

I suggest IEXT("foo") is empty, and similarly for all literals;
I think that captures the intuition that literals shouldn't
be used as properties.

> Next, we need a way to say when the same node is being
> used in two places, so we need nodeIDs or some such, even on
> literals.

We do? I don't think we need anything called "node" in
the abstract syntax at all, let alone "a way to say when
the same node is being used in two places."

>  Third, most seriously, having bnode labels on arcs
> requires some notion of scope (in the graph, not the Ntriples doc.)

It's there in my message; you left it out:

> >  > >       formula:
> >>  >               statement*

> I
> would add that it forces us to incorporate nodeIDs (actually better
> called arcIDs in this case) into the RDF graph itself


>, which is a
> 'slippery slope' idea that several people didn't like: Frank Manola,
> I believe, was one.

I don't like the idea of arcIDs either.

> >It works to my satisfaction, after considerable study
> >and implementation experience. At least two other
> >WG members also said they prefer this abstract syntax.
> >
> I would like it too if it could be made to work.

I don't see why it cannot.

> If we weren't
> restricted to simple graphs and obliged to only use urirefs as names,
> then it would work fine.

I don't understand what you mean here.

[more on the datatypes stuff separately...]

Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Wednesday, 7 November 2001 11:13:06 UTC

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