Take a look at http://www.jenitennison.com/xslt/grouping

Most of the techniques for grouping are at the XSLT level, but you can use
the basic

key[not(. = preceding-sibling::key)]

if you don't mind O(n^2) complexity.

This detects the distinct values: leave out the not() and you have an
expression that detects the duplicates.

Michael Kay
http://www.saxonica.com/
 

> -----Original Message-----
> From: Todd Ditchendorf [mailto:itod@xxxxxxxxx] 
> Sent: 19 July 2006 22:18
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  More XPath 1.0 Expression help
> 
> 
> I need some help constructing an XPath to detect nodes 
> containing duplicate string-values. I am currently restricted 
> to XPath 1.0 syntax , so no access to distinct-values() or 
> exslt unfortunately.
> 
> I have a document like this:
> 
> <dict>
> <key>Key1</key>
> <value/>
> <key>Key2</key>
> <value/>
> <key>Key3</key>
> <value/>
> <key>Key1</key>
> <value/>
> </dict>
> 
> How do I create an XPath 1.0 expression to detect the <key> 
> elements with duplicate string-values?
> 
> 
> Thanks!
> 
> 
> Todd Ditchendorf
> Software Engineer
> itod@xxxxxxxxx