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[closed] Re: N-Triples VS RDF/XML bNode identifiers

From: pat hayes <phayes@ihmc.us>
Date: Thu, 30 Oct 2003 09:54:30 -0600
Message-Id: <p06001f04bbc6e2c79852@[10.1.31.1]>
To: Dave Beckett <dave.beckett@bristol.ac.uk>
Cc: w3c-rdfcore-wg@w3.org

>On Tue, 28 Oct 2003 10:15:42 +0100, Arjohn 
>Kampman <arjohn.kampman@aduna.biz> wrote:
>
>>
>>  Dear editors of the RDF Test Cases document,
>>
>>  Last week, we stumbled across a problem in Sesame when RDF was read from
>>  an RDF/XML document and then written as N-Triples. The problem was
>>  related to the bNode identifiers, whose definition in RDF/XML and
>>  N-Triples is slightly different:
>>
>>  While parsing the RDF/XML, the parser generated bNode IDs that were
>>  legal according to the RDF/XML specs and these were written as-is to the
>>  N-Triples document. An example bNode identifier is "node09FC-1E4A-2". In
>>  RDF/XML, the dashes (and underscores, etc.) are legal characters for
>>  bNode identifiers. In N-Triples, however, only (ASCII-)letters and
>>  number can be used. Thus the procedure sketched out above resulted in an
>>  illegal N-Triples document.
>>
>>  So, my question is: wouldn't it be convenient to make the two
>>  definitions identical?
>
>It might be convienient but sadly, I don't think it's realistic.
>
>An rdf:nodeID in RDF/XML defined at
>   http://www.w3.org/TR/rdf-syntax-grammar/#nodeIdAttr
>takes as a value a string compatible with an XML name:
>   http://www.w3.org/TR/rdf-syntax-grammar/#rdf-id
>which has a wide range of characters allowed and
>permits the full range of international characters.
>
>It is also useful to re-use this XML definition since it enables checking
>using the standard XML NCName term (which can be then checked
>by XML schema languages which likely support that)
>
>The subset that are also legal as N-Triples is thus rather narrow.

?? I fail to follow this. The XML spec is rather 
wide, we have to follow it, so we have to be 
rather narrow? What??

>N-Triples also has had a (weak, but remains, "would be-nice")
>requirement to keep itself as a subset of N3.

!!!??!!  Where did that come from? Has the WG ever made that decision?

>  N3 imposes several
>restrictions on the names that are allowed, and they vary between
>implementations.  The current set of allowed names define dby
>   http://www.w3.org/TR/rdf-testcases/#name
>is thus not likely to change. 
>
>I think '-' in particular might have other uses in N3 for paths,
>arithmetic, a funky -_ encoding scheme or may be reserved or unwise.
>You'd have to ask the N3 developers, since I can't recall all the details.
>
>Please reply, copying www-rdf-comments@w3.org whether this response
>is an acceptable disposition of your comment.

I hope it isn't considered acceptable. Our syntax 
is constrained by N3??? That is news to me and I 
think it is ridiculous. N3 isnt even properly 
defined anywhere, it is not a standard and it has 
virtually a nonexistent user community outside 
the W3C itself. I bear the N3 developers no 
ill-will, but it is insane for us to be 
constraining our syntax (and inconveniencing our 
potential users) because of undocumented 
syntactic vagaries of a few hackers.

Pat

>Thanks
>
>Dave


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Received on Thursday, 30 October 2003 10:54:38 EST

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