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Re: [Xquery] 3.3.2 Filter Expressions (editorial comment on example)

From: Don Chamberlin <chamberl@almaden.ibm.com>
Date: Tue, 3 Aug 2004 15:16:39 -0700
To: David Carlisle <davidc@nag.co.uk>
Cc: public-qt-comments@w3.org
Message-ID: <OF431E7B33.51FBF1FB-ON88256EE5.007941FD-88256EE5.007A2C30@us.ibm.com>
David,
Thanks for your comment. Actually, I think that your example contains an 
Axis Step rather than a Filter Expression. The expression 
*[@id='tiger'][1]  consists of  "*", which is an Abbreviated Forward Step, 
followed by "[@id='tiger'][1]", which is a Predicate List. Together these 
make up an Axis Step.

It's not easy to find a reasonable example of a filter expression inside a 
path expression!
Regards,
--Don Chamberlin




David Carlisle <davidc@nag.co.uk> 
Sent by: public-qt-comments-request@w3.org
08/03/2004 09:42 AM

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Subject
[Xquery] 3.3.2 Filter Expressions (editorial comment on example)








the last example of a filter expression says:

  The following example illustrates the use of a filter expression as a
  step in a path expression. It returns the element node within the
  specified document whose ID value is "tiger":

  fn:doc("zoo.xml")/fn:id('tiger')


That path expression has two steps, both of which are filter expressions 
in the strict sense as zero predicates are allowed, but it isn't really
what one would naturally call an example of a filter expression in a
step.

 fn:doc("zoo.xml")//*[@id='tiger'][1]

might be a better example (even if it's less efficient code)

David

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Received on Tuesday, 3 August 2004 18:17:16 UTC

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