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An alternative namespace for XML Schema datatypes

From: Howard Katz <howardk@fatdog.com>
Date: Mon, 25 Apr 2005 09:55:15 -0700
To: "'RDF Data Access Working Group '" <public-rdf-dawg@w3.org>
Message-ID: <JMEJKDCPGHHIANHOMPDBKEJACNAA.howardk@fatdog.com>

Two things:

(1) I've noticed that the sparql spec uses both xs: and xsd: as prefixes to represent the XML Schema namespace, <http://www.w3.org/2001/XMLSchema>. Wouldn't it be better, for consistency sake, if we standardized on one or the other? 

(2) Whichever prefix we adopt,  there's an entirely different namespace that's also available for the purpose of representing XML Schema datatypes: <http://www.w3.org/2001/XMLSchema-datatypes>; it's provided for specifications that need datatype support but don't want to reference the rest of the XML Schema infrastructure. To wit, as stated in the XML Schema Part 2: Datatypes recommendation [1]:

    To facilitate usage in specifications other than the XML Schema
    definition language, such as those that do not want to know
    anything about aspects of the XML Schema definition language
    other than the datatypes, each built-in datatype is also defined
    in the namespace whose URI is:

    * http://www.w3.org/2001/XMLSchema-datatypes

    This applies to both built-in primitive and built-in derived
    datatypes.

This seems exactly applicable to our circumstance, and I'd like to recommend we at least discuss it. I do recognize there might be other reasons for not adopting the datatype-specific variation (eg, such as the fact that the RDF syntax specification [2] and related recommendations and existing RDF apps already use the more common, non-datatype-specific namespace). It just strikes me that the datatype-specific namespace is cleaner and more appropriate to what we're doing.

Finally, there's a related question of whether we should allow default prefixes, including one for XML Schema datatypes, as is done in the XQuery working drafts ([3] and [4]). I did a quick search of the dawg archives on this but couldn't find anything, tho Andy has a revision note, 1.244, on the subject. In any event that's a separate issue from the one I'm discussing (for the moment at any rate).

Howard


[1] http://www.w3.org/TR/xmlschema-2/#namespaces
[2] http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-datatyped-literals
[3] http://www.w3.org/TR/xpath-functions/#namespace-prefixes
[4] http://www.w3.org/TR/xquery/#id-namespace-decls
Received on Monday, 25 April 2005 16:53:35 GMT

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