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Re: Review of new HTTPbis text for 303 See Other

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 14 Jul 2009 10:01:21 -0500
Cc: Richard Cyganiak <richard@cyganiak.de>, "Roy T. Fielding" <fielding@gbiv.com>, Jonathan Rees <jar@creativecommons.org>, Julian Reschke <julian.reschke@gmx.de>, HTTP Working Group <ietf-http-wg@w3.org>, www-tag@w3.org
Message-Id: <6BDA530A-C88E-4CE9-A03B-ED8FD27E38D6@ihmc.us>
To: Xiaoshu Wang <xiao@renci.org>

On Jul 14, 2009, at 9:01 AM, Xiaoshu Wang wrote:

> Pat Hayes wrote:
>
> <snip>
>>> on these two counts, you end up ranting against a POV that I do  
>>> not hold.
>>>
>>> I especially continue to maintain that any talk about denotation  
>>> is out of place on the HTTP protocol level. There is no such thing  
>>> as denotation in the universe of the Hypertext Transfer Protocol.  
>>> Yes, people obviously use HTTP URIs to denote all sorts of things,  
>>> and a lot can be said about how one should model resources and  
>>> representations based on the things one wants to denote, and what  
>>> one can or cannot infer about the denotation of a URI based on  
>>> HTTP interactions, but none of this matters one bit for the actual  
>>> operations of the protocol.
>>
>> Seems to me that this may have been true before http-range-14, but  
>> it is not a stance that can possibly be maintained in the face of  
>> that decision. And your final sentence above is, surely you can  
>> yourself see, tendentious. If the HTTP 'layer' really were  
>> completely unconcerned with denotation, how could one *possibly*  
>> infer anything about what a URI denotes from *anything* about HTTP  
>> interactions?
> The assumption here is that httpRange-14 is the right direction.   
> But that is a big *if*. If anything, this debate only shows how  
> *bad* that this whole idea of httpRange-14 and information resource  
> thing is.

As I said in another post, I think http-range-14 is terrible, but all  
the alternatives are worse.

>>> The protocol is just about pushing representations around.
>>
>> Well, I would be delighted if this were true. But then the HTTP  
>> specs should not claim or even hint at the idea that URIs can  
>> "identify" non-computational things, or that such things can have  
>> "representations" in its specialized sense. (It would be very good  
>> manners, in fact, to clarify just what that highly specialized  
>> sense of "representation" is, and state explicitly that it is not  
>> intended to cover any wider sense of representation, for example  
>> the sense in which it it used in such phrases as "knowledge  
>> representation".) And you should be quite open and clear about the  
>> fact that this view of HTTP is not compatible with the http- 
>> range-14 decision.
> The HTTP protocol should be about pushing representation around.   
> And it shouldn't careless about if its URI denotes or identifies  
> anything.  The latter is up to the one who implements that  
> particular URI.   Let's not ignore the existence of such entities  
> because it is those who expressed their denotation semantics.
>
> Also, let's us not play linguistic tricks.  If the owner of "http://example.com/a.hamburger 
> " makes it to denote a hamburger. Then HTTP-GET "http://example.com/a.hamburger 
> " means "get me an awww:representation" of the hamburger. But it  
> does NOT mean the "get" like in "get me that hamburger" as what we  
> would say in front of a grill.

Of course not. But it also does not mean, "get me an  
awww:representation" of the hamburger. Or at least, it had better not  
mean that, since hamburgers don't have awww:representations. Web pages  
about hamburgers can represent (not awww:represent) a hamburger, and  
they of course have awww:representations. But an awww:repreresentation  
of a representation of X is not an awww:representation of X.

> To think otherwise is to hallucinate.

Quite.

>
> httpRange-14 was at first designed to prevent people from episodes  
> of this kind of hallucination.  But at the end, it ends up with its  
> own one -- the hallucination of the information resource.

I don't like the terminology (and I don't think we need it, and  
especially do not need to be debating its exact meaning), but the  
general idea is clear enough: its the thing that HTTP returns the  
awww:representation of. That is certainly not a hallucination, because  
you just made HTTP contact with it.

Pat

>
> But let's get real.  Let's not temper the HTTP semantics with our  
> own view on what the world or the Web ought to be.  Sure, you (or  
> y'all) can have your wonderful world of "information resources".  It  
> is none of my business.  But -- PLEASE, don't push it upon me. I am  
> just not sophisticated enough to appreciate that delicate wonder.  
> And most of all, I don't care.
>
> Xiaoshu
>
>

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Received on Tuesday, 14 July 2009 15:02:50 GMT

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