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Canonical URIs

From: Mark Baker <distobj@acm.org>
Date: Mon, 25 Mar 2002 15:20:39 -0500 (EST)
Message-Id: <200203252020.PAA29976@markbaker.ca>
To: www-xml-schema-comments@w3.org

I became aware of an issue while following www-tag, as relayed by David
Orchard[1] from Joseph Reagle's initial post[2], and elaborated upon by
Noah Mendelsohn[3].

I agree with Norm Walsh when he said[4] that, without knowledge of a
specific URI scheme, an agent performing a comparison can only rely on
lexicographic equivalence.  This seems quite fundamental to me.

Noah said[3];

 The question is, if I build a subtype of anyUri that accepts only:


 will it also accept uppercase?

I believe that the answer is "no", because an enumeration is a generic
means of limitation, and has no built-in notion of equivalence, or of
messing with the equivalence semantics of the parent type.

So, an instance of the aforementioned anyURI subtype would be considered
equivalent to the URI "http://www.IBM.com".

 [1] http://lists.w3.org/Archives/Public/www-tag/2002Mar/0111
 [2] http://lists.w3.org/Archives/Public/www-tag/2002Feb/0129
 [3] http://lists.w3.org/Archives/Public/www-tag/2002Mar/0126
 [4] http://lists.w3.org/Archives/Public/www-tag/2002Mar/0157

Mark Baker, Chief Science Officer, Planetfred, Inc.
Ottawa, Ontario, CANADA.      mbaker@planetfred.com
http://www.markbaker.ca   http://www.planetfred.com
Received on Monday, 25 March 2002 15:15:30 UTC

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