W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > June 2001

[Fwd: aboutEach: attr val use/mention bug]

From: Dan Connolly <connolly@w3.org>
Date: Mon, 04 Jun 2001 15:48:13 -0500
Message-ID: <3B1BF40D.C8CD7A6E@w3.org>
To: w3c-rdfcore-wg@w3.org
Hmm... I thought I was assigned an action to
report a bug in the specification of aboutEach,
but I don't see it.
  http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001Jun/0008.html
Anyway...

reviewing the issues list,
  http://www.w3.org/2000/03/rdf-tracking/
this seems to raise a new issue, so I sent it to www-rdf-comments.

It turned out to be more than just a typo...

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/

attached mail follows:


Regarding:

  The value of an aboutEach attribute must be a
  container.

  -- http://www.w3.org/TR/REC-rdf-syntax/#containers

That seems to be a use/mention bug:
The value of an aboutEach attribute is a URI reference;
one that *denotes* a collection, no?

The spec continues:

  Using a distributive referent on a container is the same
  as making all the statements about each of the members
  separately. 

but that doesn't clearly specify how to determine the
members of a container.

For example, consider using a subproperty of rdf:_2
to specify the second member of a collection:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
  xmlns:ex="http://example/vocab#">
  <r:Description r:about="#books"
  xmlns:r="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
    <r:type
    r:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag" />

    <r:_1 r:resource="#book1" />

    <ex:member2 r:resource="#book2" />

    <r:_3 r:resource="#book3" />
  </r:Description>

  <rdf:Description rdf:aboutEach="#books">
    <dc:rights xmlns:dc="http://purl.org/dc/elements/1.1/">all
    mine!</dc:rights>
  </rdf:Description>


  <rdf:Description rdf:about="http://example/vocab#member2">
    <rdfs:subPropertyOf
rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#_2"/>
  </rdf:Description>
</rdf:RDF>


What are the members of #books? is #book2 one of them?
I can deduce, from the specification of rdfs:subProperty,
that it is. But knowledge of rdfs:subProperty is not
required for parsing rdf:aboutEach syntax, is it?

I tried it with SiRPAC and got:

///////
Errors during parsing


Fatal error: Unresolved internal reference to books
   (Line number = 25, Column number = 4)
\\\\\\\


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Monday, 4 June 2001 16:48:21 EDT

This archive was generated by hypermail pre-2.1.9 : Wednesday, 3 September 2003 09:37:01 EDT