Re: The 'resource' identified by a namespace name URI should be the namespace

I think I've started to figure this out finally....

On Thu, Jun 01, 2000 at 08:06:28PM -0400, Clark C. Evans wrote:
> On Thu, 1 Jun 2000, Michael Mealling wrote:
> > In other words, an injective quality is really irrelevant....
> The injective function is only relevant if:
> 
>   * one wishes to compare namespaces *as* resources

No one has suggested doing that. You don't compare resources. You
compare their identifiers....

>   * one does not which to resove the resource from the URI

Whether or not one may wish to do that. The 'namespace' is still known
by its name. The resource merely acts as one of many possible electronic
representations of it....

> If you wish to compare resources based upon URIs, an
> injective (1-1, unique, etc.) function is needed from 
> the URI space into the resource space. 

Ok. I see the problem here. "Resource" as we (I) have been using the
term is a _logical_ thing, not a specific set of bits and bytes.
In many cases the electronic representation of that logical thing
can have many different representations (html, text, gif, png, etc).

In order to compare two Resources (the logical thing) you can ONLY
compare their identifiers and thus, since all you have to compare
is the identifier, if one does not equal the other then the logical
things they identify are different.

> In the case that we stick with the current specification's
> definition of the namespace *as* the URI string, and not 
> as a resource it refers to; then the function is not 
> required, and hence, the injective debate is moot.

Right. What our problem seems to be is a terminology conflict.
In my terminology universe the namespace is the resource but it
is a logical thing that is only known or handled by its URI. This
is essentailly the same as saying that the namespace _is_ its URI
but the distinction is subtle but important. A URI can resolve to
various sequences of bits that act as an electronic representation
of that logical thing. Are those bits the resource? No, they're
simply one representation of it. If you find another sequence of bits
by resolving another different URI and those sequence of bits happen
to be the same, you're not saying that the resources are equal
since the only way to talk about the logical Resource is by its URI.

Using your terminology, I think there is an injective quality to URIs
since in your terminology space the namespace is the logical thing.

Did that make sense?


-MM

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Michael Mealling	|      Vote Libertarian!       | www.rwhois.net/michael
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Received on Thursday, 1 June 2000 20:21:55 UTC