Re: Clarifying what a URL identifies (Four Uses of a URL)

Larry Masinter writes:

>    indicates(context) (URI)  -> Concept

I'm a little fuzzy on what you mean by context.   Would it be fair
to simply have several different kinds of indicator functions and drop
the notion of context?   

> The definition of a URI scheme should define the
> 'identifies' function; it cannot easily define
> any 'indicates' functions. For 'http', the 'identifies'
> function winds up being "whatever you connect to
> by sending HTTP messages to the server designated by
> the host:port of the URI, using the path of the URI,
> at the time that the 'identifies' function is invoked
> by an interpreter."

What do I connect to when I GET   It's not a
computer (there are lots of them answering at that address), it's not
an Apache process (there are lots of them answering on each machine),
...  Is it a file?  Is the kernel which handles the file?  That file
gets checked out of CVS whenever it's changed -- is it the CVS server?
Heck, is it the person who last modified the file?

I'm not being facetious -- I really can't get a grip on a particular
conceptual thing when you say "whatever you connect to."  What I can
mentally grip is shared memory locations [1], although I realize
that's just another abstraction [2].   I think you're going for the
"communications end-point" model [3], which feels very natural and
right until I look closely.

> In this model, 'identifies' is construed narrowly.
> But the range of 'indicates' can be quite broad.

Yeah, that all sounds good to me.

> RDF uses an 'indicates' function. When I use
> to talk about the World Wide Web
> Consortium or the web server or a web page at
> a particular point in time -- in each case, this
> is a different context for the 'indicates'
> function.

Hrm.  None of those are the "identifies" function?   This starts to
sound like RDF uses a many-to-many mapping, which isn't very helpful.

I'm happy with one identifies function and one indicates function.  My
problem with RDF is that you can't tell which its using sometimes.

    -- sandro


Received on Friday, 24 January 2003 02:18:05 UTC