exslt:node-set() isn't defined in the W3C standard so it's hard to argue
that any implementation of it is incorrect.

But I find it hard to imagine a coherent instance of the XPath 1.0 data
model in which there are four elements reachable by the expression "/*", and
yet none of those elements is reachable using the preceding axis from any
other.

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

> -----Original Message-----
> From: Andrew Welch [mailto:andrew.j.welch@xxxxxxxxx] 
> Sent: 10 December 2007 16:06
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  XSLT 1.0 - are parentless elements in a 
> node-set siblings?
> 
> Given:
> 
> <foo>
>  <baz>a</baz>
>  <baz>b</baz>
>  <baz>a</baz>
>  <baz>b</baz>
> </foo>
> 
> and a stylesheet that finds unique values using the preceding 
> axis on a node-set:
> 
> <xsl:stylesheet
>     xmlns:exslt="http://exslt.org/common"
>     xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
> 
>     <xsl:variable name="baz-rtf">
>         <xsl:copy-of select="//baz"/>
>     </xsl:variable>
> 
>     <xsl:variable name="baz" select="exslt:node-set($baz-rtf)"/>
> 
>     <xsl:template match="/">
>         <xsl:for-each select="$baz/baz[not(. = preceding::baz)]">
>             <xsl:value-of select="."/>
>         </xsl:for-each>
>     </xsl:template>
> 
> </xsl:stylesheet>
> 
> Xalan produces:
> 
> "abab"
> 
> whilst Saxon 6.5.5 gives (the expected result):
> 
> "ab"
> 
> It seems to be because the elements copied to "baz-rtf" don't 
> have a common parent element, they aren't siblings in Xalan...
> 
> If I modify the rtf to have a common parent:
> 
>     <xsl:variable name="baz-rtf">
>         <root>
>             <xsl:copy-of select="//baz"/>
>         </root>
>     </xsl:variable>
> 
> then it generates the expected results using both Saxon and Xalan...
> 
> Which is correct in this case?
> 
> cheers
> andrew