Re: Divide the problem

Julian Reschke wrote:
> 
> Dan Connolly wrote:
> 
> > > What it says is
> > > that you can take the URI ref to *identify* the namespace, that's it.
> >
> > If I understand you (and if I take the liberty of
> > assuming you meant URI in stead of URI ref just there),
> > you're saying that
> >       some URI i identifies a namespace N
> > does not imply that
> >       the resource identified by i is N
> >
> > To me, those are just different ways of saying the same thing.
> > How can one be true while the other is not?
> 
> Because "identify" to me means "names", and it does not mean "is identical
> to".

I agree; I did not use identify/name to mean "is identical to".

> Just because I pick a URI as a namespace name doesn't make namespace
> identical to what the URI stands for.

It seems to me that it does. I am at a loss for words to clarify...
can we switch from English to the language of logic/math?

The URI spec (http://www.ietf.org/rfc/rfc2396.txt)
essentially establishes
	identifies: URI -> Resource
so that "The URI i identifies the resource r" can be written
	identifies(i) = r

OK so far?

Then, looking at "I pick a URI as a namespace name" ... let's
call that URI i1, so that "what the URI stands for"
can be written
	identifies(i1)

Let's call "the namespace" n1. Then you're saying
that it's not necessarily the case that
	identifies(i1) = n

That means there's some other function
	namespace-named-by: URI -> Namespace
so that
	namespace-named-by(i) = n
but
	namespace-named-by(i) != identifies(i)


That's a logically coherent viewpoint, but at the
cost of introducing this distinct
namespace-named-by function, which has not
been necessary for any of the previous
specs (HTML, HTTP, URIs, ...) and doesn't
seem necessary now.

Up to the namespace spec, there's been just one
thing that each URI identifies in the Web.
That is, there has been just one Web.
It's logically coherent to consider splitting
the Web between Namespaces
and Everything Else, but I find it hard
to imagine why anybody would want to do that.

Everything else has fit into the Web of
Resources: text documents, images, objects
with methods, mailboxes, mail messages,
concepts identified by UUID or OID, and
on and on. Why splinter Namespaces out
from this space?



> Sure, but I would argue that http://www.w3.org is not necessarily the right
> place to do experiments like that. If it can't be avoided, I would still
> prefer that the schema document returned actually comes with a statement
> that this is just experimental usage of namespaces / schema.

Fair enough.


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/

Received on Thursday, 8 June 2000 18:40:48 UTC