W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > March 2003

Re: reagle-01, reagle-02 issues

From: Graham Klyne <GK@NineByNine.org>
Date: Tue, 04 Mar 2003 14:31:08 +0000
Message-Id: <>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Cc: pat hayes <phayes@ai.uwf.edu>, w3c-rdfcore-wg@w3.org

Er, Jeremy, which requirements does Pat's suggestion not meet?


At 11:52 PM 2/28/03 +0000, Jeremy Carroll wrote:

>>I took this comment as a rhetorical question meaning, "why bother even 
>>getting into canonicalization if you have implementation variance?" and 
>>hence suggesting a fourth option, which you did not consider:
>>D. Ignore XML canonicalization and treat XML literals as strings, ie the 
>>L2V mapping is the identity.
>>Then the entire rdf:XMLliteral datatype machinery is just an elaborate 
>>way of encoding the old 'XML bit', which I thought was the original 
>>intent in any case. Introducing XML canonicalization seems to have been 
>>one those neat ideas that got slipped in without too much discussion and 
>>has turned out to be a tar-pit. I am particularly concerned that this 
>>ugly mess is now centrally included in the very core of RDF. I would hope 
>>that many 'cheap and cheerful' RDF engines wouldn't even want to know 
>>about XML, still less about XML canonicalization.
>This really does not meet the requirements ...
>XML parsers really really have variability, when building RDF/XML parsers 
>we have to work out how to deal with that.
>So the simple webont examples where they want a single well-defined 
>denotation of some literal constructed with an rdf:parseType="Literal" 
>cannot be addressed simply by saying "use the original string".
>In some real contexts there isn't a string to use (e.g. parsing a DOM tree).
>We could have put all the work in the parser, and then the semantics could 
>just use the string - that may be your preference, but it's too late now.
>In practice I would expect a webont impl to work that way. However, I also 
>believe in practice that there will be cheaper parsers for low footprint 
>environments which don't do this.

Graham Klyne
PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
Received on Tuesday, 4 March 2003 10:21:05 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 14:54:04 UTC