Re: http, the whole http, nothing but http

In reply to my complaint about

>Roy Fielding wrote:
> > any URI, no matter how abstract its referent or how obscure the
> > scheme, can be placed in the context of a dereferencing system
> > that supplies representations of whatever is supposedly identified
> > by that URI.

Graham Klyne wrote:

> I read what he said as noting that it is *possible* to treat any
identifier 
> as dereferencable, not that to do so would always be desirable.

I was complaining about "supplies representations" as a particular
kind of mode of "dereferencing".  When you "dereference" a "telnet:"
URI,
you actually interact with a service. It's a stretch to call it
"retrieving representations".  When you "dereference" a "mailto:" URI,
you wind up sending mail to a mailbox. What is the "representation"
that gets "retrieved".

Before deciding whether it is *possible* to consider all identifiers
as dereferencable, you'll have to define "dereferencable" in a way
that doesn't leave the statement empty and yet covers all of the
ways of interacting with URIs.

>  As such, I 
> regard his comment not as describing a model but explaining a
possibility, 

But the comment says "any URI", not just "some URIs". The model
either admits this assertion (for any URI, of being dereferencable
by supplying representations) or it does not.

> which in turn suggests (to me) that a model that depends on
hard-and-fast 
> distinctions between identifiers and locators doesn't always stand up.

I'm not sure where this came from. I certainly don't believe that
there can be hard-and-fast distinctions between identifiers and
locators. I do think there can be general guidelines for naming
and designing new schemes.

Larry

Received on Sunday, 5 October 2003 02:08:16 UTC