Try:

<xsl:for-each-group select="$list" group-by=".">
  <xsl:sequence select="current-group()[last()=1]"/>
</xsl:for-each-group> 

Regards,

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

> -----Original Message-----
> From: Houghton,Andrew [mailto:houghtoa@xxxxxxxx] 
> Sent: 05 January 2010 18:41
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  Retrieving sequence of unique strings from 
> another sequence
> 
> I have a sequence of strings, e.g., ('abc', 'def', 'def', 
> 'ghi'), and I want to create a new sequence that will have 
> only the unique strings in it.  The XSL 2.0 function 
> distinct-values is not what I want because:
> 
>   <xsl:variable name="list" as="xsd:string*" select="('abc', 
> 'def', 'def', 'ghi')" />
>   <xsl:variable name="uniq" as="xsd:string*" 
> select="distinct-values($list)" />
> 
> will result in a sequence of ('abc', 'def', 'ghi') which is 
> not what I'm looking for.  What I am looking for is the 
> sequence ('abc', 'ghi').  Unix people will recognize that 
> distinct-values() returns the result of the uniq command 
> without any options.  While what I'm looking for is the 
> result of the uniq command with the -u option.
> 
> Can anyone suggest how I might use one or more XSL 2.0 
> functions to return only the unique strings.
> 
> 
> Thanks, Andy.