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Re: <sandro> PatHayes, can you formally define g-box for us?

From: Richard Cyganiak <richard@cyganiak.de>
Date: Thu, 13 Oct 2011 12:47:45 +0100
Cc: Pat Hayes <phayes@ihmc.us>, public-rdf-wg WG <public-rdf-wg@w3.org>
Message-Id: <747EEB72-C6CA-4E80-A56B-A4A40E185966@cyganiak.de>
To: Ian Davis <ian.davis@talis.com>
On 13 Oct 2011, at 12:40, Ian Davis wrote:
>> > REST defines a resource as a function from times to representations.
>> Well, no, REST defines a resource as a a time-varying function from requests to representations.
> Well, no, REST doesn't mention requests.
> Fielding
> "...a resource R is a temporally varying membership function MR(t), which for time t maps to a set of entities, or values, which are equivalent. The values in the set may be resource representations and/or resource identifiers. A resource can map to the empty set, which allows references to be made to a concept before any realization of that concept exists -- a notion that was foreign to most hypertext systems prior to the Web. Some resources are static in the sense that, when examined at any time after their creation, they always correspond to the same value set. Others have a high degree of variance in their value over time. The only thing that is required to be static for a resource is the semantics of the mapping, since the semantics is what distinguishes one resource from another."

Hm, I must have some other phrasing in mind – I'm 100% certain I've heard Fielding phrase it using requests.

>> > IRI----HTTP/"identifies" ---- g-box
>> > IRI----denotes/names-----g-snap
>> That seems wrong. “Identifies” and “denotes” are distinct mechanisms, but it has always been the goal to align them wherever possible. The phrasing above seems to explicitly require that they are different – a URI “identifies” one thing but “denotes” another. That's bad.
> Why is it bad if identify is not identical with denote?

Because “identifies” is how the web works – it's the basis for virtually all uses of URIs outside of the narrow domain of RDF.

As an example, it makes sense to a PUT to a graph store, but it doesn't make sense to PUT to a g-snap. We couldn't say “<u> :accessAllowedFor <ian>” without breaking RDF Semantics, for example.

Received on Thursday, 13 October 2011 11:49:16 UTC

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