- From: Stefan Eissing <stefan.eissing@greenbytes.de>
- Date: Mon, 23 Sep 2002 12:57:45 +0200
- To: "Roy T. Fielding" <fielding@apache.org>
- Cc: "Williams, Stuart" <skw@hplb.hpl.hp.com>, "'Michael Mealling'" <michael@neonym.net>, www-tag@w3.org
Am Freitag den, 20. September 2002, um 20:52, schrieb Roy T. Fielding: > >> Even seen it asserted in many places that a URI unambiguously >> identifies a >> single resource. I've not seen it asserted the other way round... >> that a >> resource is identified by a single URI. Such an assertion might be a >> consequence of a definition of resource like Roy's about a >> resource being a >> conceptual mapping over time between an identifier and a set of >> time varying >> equivalent representations. > > Nope, it is N:1. My definition of a resource does not say how many URI > identify that resource. I don't even mention them in the same > paragraph. In another thread on the uri list, you pointed out that: "The mapping [of URIs] is the resource and the resource always exists,[...]" [1] In terms of Tim Bray's alternatives (either the resource is the uri (a) or it is a separate concept(b)) you seem to allow for both to be true. I get the feeling I missed something here. Could you explain? //Stefan 1. http://lists.w3.org/Archives/Public/uri/2002Sep/0024.html >>> An N:1 mapping of a URI to a Resource >>> would require some way to determine more information about a Resource >>> other than its URI and that information does not exist at this layer >>> of the architecture. > > No it wouldn't -- it merely recognizes their existence so that such > understanding can be used at other layers. HTTP had a mechanism at one > point that would have provided information about the other N, but it > was removed due to lack of consensus. CDN depends on similar notions. > > Besides, right now we are talking about a document that already covers > many layers at the same time. > > .....Roy > >
Received on Monday, 23 September 2002 06:58:21 UTC