Response to comments on "local" namespace in XQuery: "[XQuery] 'local' namespace" and "[QT] CER-14 local:"

Martin and Mary,

This message is an official XML Query WG response to two comments, one from 
each of you.  The messages containing the comments are:

http://lists.w3.org/Archives/Public/public-qt-comments/2004Feb/0418.html 
(entitled "[XQuery] 'local' namespace  ")
and
http://lists.w3.or/Archives/Public/public-qt-comments/2004Feb/0836.html 
(entitled "[QT] CER-14 local:")

In these comments, you each asked what is the purpose of the "local" 
namespace (although Mary's message contained additional, related questions).

The Query WG considered both of these comments at its most recent meeting 
and asked me to respond on its behalf.

The reason that there is a distinguished namespace for user-defined 
functions, rather than allowing those functions to be contained in the same 
namespace as the functions defined by the Functions and Operators 
specification (commonly known as the "fn:" namespace) is to ensure that 
there is no collision between the names of user-defined functions and 
F&O-defined functions in some future version of XQuery and/or 
XPath.  Allowing user-defined functions to be contained in the same ("fn:") 
namespace as the F&O-defined functions would violate the principle of least 
astonishment when running applications using XQuery (or XPath) suddenly 
began to fail when implementations were upgraded to a new edition of the 
Functions and Operators specificaion.

Users are, of course, free to create their user-defined functions in a 
namespace of their choosing.  However, as a benefit to users, the XML Query 
WG has chosen to predefine a namespace, using the prefix "local" associated 
with the namespace URI 
"http://www.w3.org/2003/11/xquery-local-functions".  The XML Query WG 
simultaneously prohibited the use of any other of XQuery's predefined 
namespaces (those commonly known by the prefixes "xs:", "xsi:", "fn:", and 
"xdt:").

We believe that this response resolves both of the comments identified 
above.  We would be grateful if you would respond indicating your agreement 
with this resolution.

Hope this helps,
    Jim

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Jim Melton --- Editor of ISO/IEC 9075-* (SQL)     Phone: +1.801.942.0144
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=  Facts are facts.  However, any opinions expressed are the opinions  =
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Received on Wednesday, 31 March 2004 22:27:29 UTC