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From: Ivan Herman <ivan@w3.org>
Date: Fri, 23 Jan 2009 10:09:50 +0100
Message-ID: <4979895E.7040908@w3.org>
To: Bijan Parsia <bparsia@cs.man.ac.uk>
CC: W3C OWL Working Group <public-owl-wg@w3.org>

Bijan Parsia wrote:
> On 22 Jan 2009, at 09:52, Ivan Herman wrote:
>> Having said that, we would have backward compatibility issues in the
>> sense that we may have ontologies that _today_ are not kosher but would
>> become so in future. But I guess that should be fine, it fits our open
>> world view...
>> Sigh:-)
> Here's another possibility: Leave it to be tied to the latest Unicode
> but point out that serializations and parsers (and apis) would need to
> be updated. That way, we do not discriminate against people who need the
> new characters. In the conformance document, we could discuss this and
> even suggest (require?) that *implementations* indicate which version of
> Unicode they support. This would add some implicit pressure to keep up
> to date wrt Unicode.

Yes, that may be a way forward indeed. More exactly: the text should
spell out what users might face with serializations that have not been
updated to Unicode 5 or later. (Whether we should say something on what
serializations need to do or not may not be appropriate. But I might be
too cautious:-)

Just for the records and for our editors, this is how a reference looks
like in the character model Rec:

The Unicode Consortium, The Unicode Standard, Version 4, ISBN
0-321-18578-1, as updated from time to time by the publication of new
versions. (See http://www.unicode.org/unicode/standard/versions for the
latest version and additional information on versions of the standard
and of the Unicode Character Database).
]]] http://www.w3.org/TR/charmod/

(Although we would have to put version 5 there.)

> Indeed, I rather suspect that RDF should update, esp. given the (widely
> loathed) XML revision 5. Certainly the *model* should track Unicode
> latest....perhaps this could be considered an errata? Given the right
> conformance description, such a change would have no impact on
> implementations.

Given that this came up, I think recording an errata for RDF, stemming
from this group, might be a good idea indeed!

(To be fair to the RDF group of the time: this issues were way murkier
at the time. The I18N guys tried to clarify things a bit but, for
example, the character model document came out a year after RDF...)

> (Actually, there's an interesting question about RDF now. RDF/XML refers
> normative to XML revision 2! Wacky. That means that RDF parsers should
> reject XML documents that use revision 3-5 features? Are there any 3-4
> features which make a difference?)

Sigh:-( I am not sure...

> BTW, I'm in favor of making rdf:text/xsd:string whatever have finite
> alphabets. Discussions with Birte about her datatype implementation seem
> strongly in favor (mostly in the reuse of existing automata libraries).
> There's a number of ways to handle this including parameterizing
> text/string (i.e., with unicode version).

I hear Boris' argument on ontologies becoming inconsistent over time.
Having said that: I would be curious to see how frequent this (in my
view, hightly theoretical!) issue is. Defining the number of characters
to be infinite is a little bit unnatural indeed...

A slight procedural issue, though (sorry Bijan! Breaking our rule
here:-(: I think we should register a separate LC comment on the
infinity of characters if we want to. This does not have anything to do
with Martin's comment...


> Cheers,
> Bijan.


Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf

Received on Friday, 23 January 2009 09:10:28 UTC

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