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Re: reagle-01, reagle-02 issues

From: Graham Klyne <GK@NineByNine.org>
Date: Tue, 25 Feb 2003 15:56:37 +0000
Message-Id: <>
To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
Cc: <w3c-rdfcore-wg@w3.org>

I think Jeremy's #2 risks putting off a large number of potential RDF 
uses.  I think that keeping the cost of entry low is vital.


At 04:06 PM 2/24/03 +0100, Jeremy Carroll wrote:

>(Note reagle-01 has also been submitted as part of the webont consensus
>These issues concern the design of rdf:XMLLiteral and
>Reagle reviewed on behalf of the C14N group (Digital Signatures).
>I had indicated that we were seeking expert feedback as to how well we had
>used their work.
>Reagle suggested:
>- we should use the same type of C14N throughout - I think this was intended
>for clarity - it is difficult to assess what our solution does with its mix
>of both exc-C14N and incl-C14N.
>- to remove implementation variability
>- request removing implementation variability from RDF/XML thru to domain of
>- suggest removing all implementation variability (as an example of how to
>satisfy request)
>I see the choice space as:
>1: Leave things as they are
>2: Choose a form X of canonicalization,
>    require parser to implement X
>    define lexical to value mapping as X
>3: Choose a form X of canonicalization
>    define lexical to value mapping as X
>    leave text in Syntax largely unchanged (except use X in place of current
>"exclusive canonicalization without comments"). This allows cheap and
>cheerful parsers that do not canonicalize.
>3 is now my preference - I realise it needs expansion, but before I do that
>I wish to list pros and cons, and get feedback from WG.
>Consider three use cases:
>A) cheap and cheerful RDF impl using embedded XHTML
>B) OWL or other semantically advanced use where it is desired that
>representation in domain of discourse is not implementation dependent.
>C) Embedding XSLT document inside and rdf:XMLLiteral (hence requiring
>support for preservation of not visibly used namespaces)
>A - works
>B - doesn't really work, because of comments and not visibly used namespaces
>C - might work depending on having an implementation that knows when to
>preserve not visibly used namespaces
>A: expensive
>B: works
>C: does not work
>A: works
>B: works
>C: does not work
>i.e. our current position works non-interoperably for XSLT in RDF - a use
>case that we have not seen, and that is its only advantage over soln 3 which
>interoperably does not work for XSLT in RDF.
>If we go for soln 2 or soln 3 we have to reconsider whether we wish to
>preserve comments, and which not visibly namespaces we preserve.
>I suggest preserve comments, and no namespaces that are not visibly used.
>BTW - if we go for 2 or 3 ARP will need updating - it has some support for
>preservation of not visibly used namespaces. I could ask on jena-dev whether
>anyone is using this feature.

Graham Klyne
Received on Tuesday, 25 February 2003 12:19:52 UTC

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