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Re: anonymous abouts (blank node creation)

From: Niklas Lindström <lindstream@gmail.com>
Date: Fri, 20 Jul 2007 18:30:39 +0200
Message-ID: <cf8107640707200930q24cbfb77m2ba4d78302a96229@mail.gmail.com>
To: "Ben Adida" <ben@adida.net>
Cc: "Ivan Herman" <ivan@w3.org>, RDFa <public-rdf-in-xhtml-tf@w3.org>

I agree. Hopefully we won't need this if we have the possibilities of
striping with bnode subjects - and list mechanisms - as currently
discussed.

If the need would arise to denote a bnode, perhaps this shorthand
would be nice instead of requiring a throw-away bnode name, that's
all. But I as well hope it won't be necessary.

Best regards,
Niklas


On 7/20/07, Ben Adida <ben@adida.net> wrote:
>
> Ivan, Niklas,
>
> I'll start replying to the new thread, but I want to point out my strong
> preference for not forcing authors to use the [] notation for common use
> cases. I don't think we need to, either.
>
> -Ben
>
> Ivan Herman wrote:
> >
> > Niklas Lindström wrote:
> >> Hi Ivan,
> >>
> >> I think I like this suggestion. Just to be clear, wouldn't it be
> >> necessary to write:
> >>
> >>    <div about="[_:]">
> >>
> >
> > I am not sure. Somebody (?) is supposed to write down the RDFa rules for
> > these.
> >
> >> though (and not just @about="_:")? That being the case, *perhaps*
> >> @about="[]" could be enough? Although it may not be symmetrical enough
> >
> > Yes, if you are right with the one above, than [] could also work...
> >
> > Let us wait for the exact write up of the RDFa rules for URI
> > abbreviation (/me avoid using the "C" word...)
> >
> > Ivan
> >
> >> or even look broken.. Sure it looks exactly the way blank nodes are
> >> expressed in Notation 3. But that may be unfortunate of course, since
> >> it would suggest that you could use N3 in the attribute value (which
> >> naturally isn't the case at all). That said, it does look succinct and
> >> "clean" in my eyes.. Though "_:" (within square brackets in "plain
> >> URI" attributes like @about) may be more consequential I guess.
> >>
> >> Best regards,
> >> Niklas
> >>
> >>
> >>
> >> On 7/18/07, Ivan Herman <ivan@w3.org> wrote:
> >>> Some of the issues in the past days made me thing a bit. I refer here to
> >>>  issues like
> >>>
> >>> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0143.html
> >>>
> >>> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0136.html
> >>>
> >>> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0137.html
> >>>
> >>> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0142.html
> >>>
> >>>
> >>> One of the problems we are fighting with is when to generate a new blank
> >>> node and how...
> >>>
> >>> I guess we will have something special for about values along the lines
> >>> of turtle for blank nodes, right? about="_:blabla" means a blank node
> >>> with nodeId (to use the RDF/XML terminology) "blabla". But what is the
> >>> meaning of about="_:". Well, mentally, I could say that this means a
> >>> blank node hose nodeId I do not care about, just let the system choose
> >>> whatever this wants.
> >>>
> >>> What this means is that if I say
> >>>
> >>> <div property="a:b" about="_:">blabla</div>
> >>>
> >>> that would yield
> >>>
> >>> [ a:b "blabla" ]
> >>>
> >>> Or, if there are more things in <div> the blank node would act as a
> >>> common subject, because the same rules for @about would apply.
> >>>
> >>> In
> >>>
> >>> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0137.html
> >>>
> >>>
> >>> Mark proposed that
> >>>
> >>> <div instanceof="foaf:Person">
> >>>     ...
> >>> </div>
> >>>
> >>> would automatically create a blank node and instanceof would apply to
> >>> that. In fact, we could say that the real code here is:
> >>>
> >>>
> >>> <div instanceof="foaf:Person" about="_:">
> >>>     ...
> >>> </div>
> >>>
> >>> in which case the rule from Mark simply come from our usual rules,
> >>> without any exception to instanceof (compared to the usage of @rel, ie,
> >>> to what the attribute applies to).
> >>>
> >>> The other issue was to create a list of anonymous blank nodes. Well
> >>>
> >>> <ul instanceof="rdf:List">
> >>> <li about="_:" instanceof="foaf:Person" property="foaf:name">A</li>
> >>> <li about="_:" instanceof="foaf:Person" property="foaf:name">B</li>
> >>> </ul>
> >>>
> >>> would exactly do it. Note that if of the authors have his/her own
> >>> resource, than
> >>>
> >>> <ul instanceof="rdf:List">
> >>> <li about="_:" instanceof="foaf:Person" property="foaf:name">A</li>
> >>> <li about="http://www.a.b.c" instanceof="foaf:Person"
> >>> property="foaf:name">B</li>
> >>> </ul>
> >>>
> >>> would of course do it, and keep it very symmetrical.
> >>>
> >>> We already have a rule on the creation of 'empty' nodes, ie
> >>>
> >>> <div rel="a:b">....</div>
> >>>
> >>> means setting a new blank node. We could keep that rule, too, I do not
> >>> think it would lead to any harm...
> >>>
> >>> This is really just an uncooked idea, may be absolute rubbish. But maybe
> >>> it is worth looking at it...
> >>>
> >>> Ivan
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> --
> >>>
> >>> Ivan Herman, W3C Semantic Web Activity Lead
> >>> URL: http://www.w3.org/People/Ivan/
> >>> PGP Key: http://www.cwi.nl/%7Eivan/AboutMe/pgpkey.html
> >>> FOAF: http://www.ivan-herman.net/foaf.rdf
> >>>
> >>>
> >
>
>
Received on Friday, 20 July 2007 16:30:52 GMT

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