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Re: single-ID constraint not clear [Fwd: Re: Guide: Legal syntax?]

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Wed, 30 Oct 2002 10:21:36 +0000
To: Dan Connolly <connolly@w3.org>
cc: www-rdf-comments@w3.org, "Peter F. " Patel-Schneider <pfps@research.bell-labs.com>, "Smith, Michael K" <michael.smith@eds.com>
Message-ID: <9072.1035973296@hoth.ilrt.bris.ac.uk>

>>>Dan Connolly said:
> I don't have any replacement text to suggest just now,
> but I have to agree with Peter's observation
> that the existing text isn't clear.

This text (no link), I'll assume was that which was commented on by
Peter in May, after the last working draft was published:

  [[4/ The constraint on only one rdf:ID (or rdf:bagID) for a URI in a given
   document is hidden deep in the document.  It would be much better to
   gather all these context-sensitive constraints in one place.  It would
   be even much better to remove these context-sensitive constraints, as
   there is no need to have only one rdf:ID with a particular URI in a
   document.  The development of this constraint is rather confusing, as
   there have been statements to the effect that rdf:about="#foo" is a
   synonym for rdf:ID="foo".
  ]] -- http://lists.w3.org/Archives/Public/www-rdf-comments/2002AprJun/0100.html

I responded to him and agreed to make changes:

  [[ Linking and making these constraints more prominent is a good
     idea; I will add this.

     If I recall correctly, RDF Core decided that keeping them (for
     IDs) was useful for users who could then rely on them, for
     example, when defining RDF Schema RDF/XML documents, that the
     terms being defined using rdf:ID were unique identifiers in that
     RDF/XML file.

     It is true that the constraints don't apply when using
     rdf:about="#foo" which I guess is seen more as referring rather
     than defining "foo" despite these being equivalent; rather
     rdf:ID="foo" is equivalent to rdf:about="#foo" but with the
     extra constraint.
  ]] -- http://lists.w3.org/Archives/Public/www-rdf-comments/2002AprJun/0119.html

All this is recorded in the changes section of the editors draft of
the syntax WD as:

[[Update after comments by Patel-Schneider, 2002-05-21 outlined in
  response 1 and response 2.
  ...
  Section 5.4 Constraints - added and moved the rdf:ID and rdf:bagID
  constraints there linked from the old location in the grammar. 
  ...
]]
-- http://ilrt.org/discovery/2001/07/rdf-syntax-grammar/#section-Changes

The new section 5.4 is:
  http://ilrt.org/discovery/2001/07/rdf-syntax-grammar/#section-constraints

with the test cases directly linked there.

Dave
Received on Wednesday, 30 October 2002 05:22:05 GMT

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