Re: RDF namespace conventions

At 04:13 PM 5/22/00 -0500, Al Gilman wrote:
>>At 11:51 AM 5/22/00 -0400, Tim Berners-Lee wrote:
TBL>So, the layer separation you suggest would work only with either
TBL>(a) no relative URIs -- at least a warning that XML lower layers don't
TBL>them, or
TBL>(b) change lower layers to absolutize before comparing.
TBL>Either of these would be consistent.  The second would be cleaner.
SSL>Neither of these is necessary.  You're driving the quest for 'consistency'
SSL>too deep into the underlying layers.
AG>The warning option under (a) does not require any lower-layer changes or
AG>awareness, so I cannot follow what you mean as "driving too deep," on this
AG>choice.  Option (b) is clearly invasive and disruptive.

We agree on the impact of option b.  I don't see the necessity for option a
to be implemented in lower layers at all, though it's something XML
application developers should be aware of.  (Just as they should be aware
that changing namespace prefixes breaks validation against DTDs.)

>There does not, as you have noted elsewhere, need to be enmity between
>inter-layer distinctions and trans-layer connections.

There only needs to be enmity when higher-level layers begin insisting on
changes in lower levels, which cannot be easily justified at those lower
levels and which may have effects on other applications built using a
different set of upper layers.

>The scoping of modules needs to be driven by the semantics,
>and be implemented in a layered fashion which, it appears, does not need to
>tear up the presently laid lower layers one whit. 

That is a promising viewpoint, though to be honest I'm not sure what the
rest of your message was suggesting as a solution. - "syntax is an
instrumentality, morally indefensible by itself" is an extraordinarily
controversial claim all by itself.

>XML 1.0 is light on semantics.  That is not a virtue, it is a calculated

Certainly - and a risk worth continuing.

>Tim's vision is [morally] right.  Let's see how we can, in all civility
>with regard to past syntactic commitments, make speed in that direction.

I'd leave out 'morally' there, though Tim has a vision, certainly.  Let's
stay off the morals and rightness track until it's clear what the biases of
those morals are.  I'd say it's pretty blurry right now, and it's not yet
clear where that vision takes us.

Civility, however, is probably a good thing whatever the destination.

Simon St.Laurent
XML Elements of Style / XML: A Primer, 2nd Ed.
Building XML Applications
Inside XML DTDs: Scientific and Technical
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Received on Monday, 22 May 2000 16:20:00 UTC