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Re: Helping out with canonicalization of URIs

From: by way of Martin Duerst <Tim.Bray@Sun.COM>
Date: Tue, 10 Aug 2004 16:52:12 +0900
Message-Id: <4.2.0.58.J.20040810165209.05e45fa0@localhost>
To: uri@w3.org




On Aug 9, 2004, at 11:26 AM, Roy T. Fielding wrote:

>>>   http://example.com:80/
>>
>>I think this is the same as http://example.com/ according to RFC2396bis, 
>>but that you have to climb someway up the equivalence ladder 
>>(protocol-specific equivalence) to recognize this.  It must be expected 
>>that many software packages would not recognize this equivalence.
>
>It is the same, but that is under scheme-specific normalization, not
>protocol.  It is the "http" that defines :80/none equivalence, not HTTP.

Agreed; and it would be OK, for example, for Atom to require that you do 
this, and still be perfectly consistent with 2396bis; but that doesn't mean 
2396bis requires it.

>>>   http://www.w3.org/2000/01/rdf-schema#
>>
>>I'd say this is distinct from http://www.w3.org/2000/01/rdf-schema -- an 
>>empty fragment is not the same as no fragment at all (note, when used as 
>>namespace URI in an RDF document, they certainly would not give rise to 
>>the same resource identifiers according to the RDF specifications -- see 
>>RDF syntax spec (10 Feb 2004), section 6.1.2, URI accessor)
>
>Yes.

Agreed, and here's another reason why: The semantics of the #fragid are 
defined in the context of the media type of the representation you get (if 
you ever get any), and it would be possible, although likely unwise, for 
some media type to attach semantics to an empty fragment identifier, i.e. 
example.com/foo# might be *really different* from example.com/foo.

  -Tim
Received on Tuesday, 10 August 2004 08:17:35 UTC

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