- From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Date: Wed, 23 Jan 2002 10:45:25 +0000
- To: Pat Hayes <phayes@ai.uwf.edu>
- Cc: Brian McBride <bwm@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org
At 06:04 PM 1/22/02 -0600, Pat Hayes wrote:
>Another is that a URI implicitly identifies a process which when set in
>motion will result in some value (which might itself be a name or
>referring expression in the first sense, or a document or structure in the
>second sense) being 'delivered' to the 'caller', ie as a kind of
>computational identifier whose value reflects the current 'state' of the
>Web itself. (This latter would be one way to make sense of the
>above-mentioned discussion of 'mapping' versus 'content' in RFC2396, for
>example.)
FWIW, this seems closest to the mental model that works best for me ...
roughly, a URI denotes a function that, when applied to some arguments,
returns some data entity. In, say, an HTTP GET operation, some of the
arguments are implicit (the fact that it's a GET operation, the state of
the "resource" when the function is evaluated) and some are explicit (HTTP
request parameters, request body, etc.).
[...]
>A more recent document (http://www.w3.org/TR/uri-clarification/)
>unfortunately only adds to the confusion. It notes that a 'classical' view
>partitioned URIs into names (URNs) versus location identifiers (URLs), but
>goes on to describe a 'contemporary' view which fails to classify them in
>any meaningful way. This does not add any clarity to the overall
>framework, however. This document for example states that according to the
>contemporary view, "a URL is a type of URI that identifies a resource via
>a representation of its primary access mechanism (e.g., its network
>"location"), rather than by some other attributes it may have." This seems
>to imply that the resource *is* the document that is retrieved by using
>the URL (since that is the entity that can be said to have a network
>"location"), rather than anything that such a document may indicate or
>name, such as a book in a library (cf. RFC2396). It also assumes that
>location is an attribute, which raises a number of other questions,
>including whether or not the same entity (resource) might have different
>locations at different times (by changing this attribute).
In a sense, I think this is right, in that any attempt to classify URIs
raises more questions than it answers. But I also think this is a separate
issue from the question "What is a 'resource'?" that you posed, and (if
only for political/social reasons) the classification of URIs debate should
be kept separate from consideration of your question.
#g
------------------------------------------------------------
Graham Klyne MIMEsweeper Group
Strategic Research <http://www.mimesweeper.com>
<Graham.Klyne@MIMEsweeper.com>
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Received on Wednesday, 23 January 2002 06:27:36 UTC