Re: Language = Namespace. was: How namespace names might be used

Julian Reschke wrote:
> 
> Paul W. Abrahams wrote:
> > Tim Berners-Lee wrote:
> >
> > > - a namesapce is identified by a URI.  (That is, if any resource is
> > > identified by URI u, and a namespace is identified by URI u, then that
> > > resource *is* that namespace)
> >
> > To pursue the question of what you mean by that: are all URIs
> > equally suitable
> > for that purpose, assuming only that the URI is chosen so that one can be
> > reasonably confident of its uniqueness?   If not, how would you
> > distinguish the
> > suitable URIs from the unsuitable ones?  There certainly does not
> > seem to be
> > any agreement as to what if anything should be at the resource
> > identified by
> > the URI, if indeed such a resource exists at all.
> 
> To pursue this even further:
> 
> 1) The XSLT namespace name is an URI ref that currently points to an HTML
> document "describing" the XSLT namespace,

no, it points to a resource which is represented by an HTML document
describing it. What it points to is the same resource across
time, across perspectives, etc. How that resource is represented
depends on context such as when you ask, what Accept: headers
you ask with, etc.

> 2) According to Tim, the HTLM documentation thus *is* the namespace,

no, the HTML documentation is a representation of the namespace.

And it's not just according to Tim; it's according to the standard
(IETF draft standard, that is) definition of the term
resource in the URI spec, in contrast to 'entity' or 'entity body'
in the HTTP, MIME, HTML etc. specs:


      "Resource
         A resource can be anything that has identity.  Familiar
         examples include an electronic document, an image, a service
         (e.g., "today's weather report for Los Angeles"), and a
         collection of other resources.  Not all resources are network
         "retrievable"; e.g., human beings, corporations, and bound
         books in a library can also be considered resources.
         The resource is the conceptual mapping to an entity or set of
         entities, not necessarily the entity which corresponds to that
         mapping at any particular instance in time.  Thus, a resource
         can remain constant even when its content---the entities to
         which it currently corresponds---changes over time, provided
         that the conceptual mapping is not changed in the process."

        -- http://www.ietf.org/rfc/rfc2396.txt

"resource 
     A network data object or service that can be identified by a URI,
as
     defined in section 3.2. Resources may be available in multiple
     representations (e.g. multiple languages, data formats, size, and
     resolutions) or vary in other ways. 
entity 
     The information transferred as the payload of a request or
     response. An entity consists of metainformation in the form of
     entity-header fields and content in the form of an entity-body, as
     described in section 7. "
        -- http://www.ietf.org/rfc/rfc2616.txt
        aka http://www.w3.org/Protocols/rfc2616/rfc2616-sec1.html#sec1.4


> 3) Given an RDF document referring to that URI, does it make statements
> about a namespace, a language or an HTML document???

about a namespace/language.

> 4) If all of them are *the same thing*, what happens if the HTML document is
> replaced by an XML schema document? (I think this happened recently @ the
> namespace RECs own URI).

What happens is that clients get a different representation of the
resource (i.e. the namespace/language) from what they previously got.
Just like when a GIF image is replace by a PNG.

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

Received on Tuesday, 20 June 2000 01:06:06 UTC