W3C home > Mailing lists > Public > www-ql@w3.org > January to March 2004

RE: XQuey

From: Jerome Simeon <simeon@us.ibm.com>
Date: Fri, 12 Mar 2004 13:38:28 -0500
To: "Michael Kay" <mhk@mhk.me.uk>
Cc: "'Jan Hidders'" <jan.hidders@ua.ac.be>, "'Jan Paredaens'" <Jan.Paredaens@ua.ac.be>, "'Mary Fernandez'" <mff@research.att.com>, "'Philippe Michiels'" <philippe.michiels@ua.ac.be>, www-ql@w3.org, www-ql-request@w3.org
Message-ID: <OF0A85A8DB.40EFCDBC-ON85256E55.00657FC9-85256E55.006665B0@us.ibm.com>

Sorry, I keep trying to understand why XPath works the way it does. I
should have learned my
lesson by now...
I agree that Mary's new normalization is correct.
- Jerome

             "Michael Kay"                                                 
             Sent by:                                                   To 
             .org                      Jerome Simeon/Watson/IBM@IBMUS      
                                       "'Jan Hidders'"                     
             03/10/2004 09:33          <jan.hidders@ua.ac.be>, "'Jan       
             AM                        Paredaens'"                         
                                       <Jan.Paredaens@ua.ac.be>, "'Mary    
                                       Fernandez'" <mff@research.att.com>, 
                                       "'Philippe Michiels'"               
                                       RE: XQuey                           

The XPath 1.0 specification said that attributes were not included in the
result of the following axis. I see no reason to change that.

Michael Kay

From: Jerome Simeon [mailto:simeon@us.ibm.com]
Sent: 10 March 2004 14:11
To: Michael Kay
Cc: 'Jan Hidders'; 'Jan Paredaens'; 'Mary Fernandez'; 'Philippe Michiels';
Subject: RE: XQuey

Shouldn't it also contains some attributes nodes from the same element
which are
considered (by that implementation) to be after that attribute node to be
in document order?

For instance,

let $x := <a b="1" c="2"/> return

may return either () or the attribute 'c', depending on how the
implementation deals with
document order?
- Jerome

 "Michael Kay"                                                             
                     "'Mary Fernandez'" <mff@research.att.com>, "'Jan      
 03/10/2004          Paredaens'" <Jan.Paredaens@ua.ac.be>                  
 05:21 AM                                                               cc 
                     Jerome Simeon/Watson/IBM@IBMUS, <www-ql@w3.org>,      
                     "'Jan Hidders'" <jan.hidders@ua.ac.be>, "'Philippe    
                     Michiels'" <philippe.michiels@ua.ac.be>               
                     RE: XQuey                                             

# I agree that the prose and formal meanings  of the following expression
# conflict, but I believe the formal semantics is the correct one, i.e.,
# $x/@attr/following::node() = ()

The XPath 1.0 definition is:

"the following axis contains all nodes in the same document as the context
node that are after the context node in document order, excluding any
descendants and excluding attribute nodes and namespace nodes"

(The accepted meaning of "any descendants" is "descendants of the context
node", while the accepted meaning of "attribute nodes and namespace nodes"
is "all attribute and namespace nodes")

This definition means that the following axis, starting at an attribute,
includes the children of the element containing that attribute.

Michael Kay
Received on Friday, 12 March 2004 13:39:23 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:17:16 UTC