tokenize and split

Hi,

My problem is that I need to make a stylesheet which uses str:split
work on both saxon and
xalan processors.  I understand that saxon's tokenize is similar and
have been able to use it to make the stylesheet work on saxon.
However, I'm having difficulty working out how to use
function-available to invoke saxon's tokenize if it is available
otherwise use the str:split.

So I've got the following...

	  <xsl:choose>
		<xsl:when test="function-available(str:split)">
		  <xsl:copy-of select="str:split('a b c', ' ')[1]"/>
		</xsl:when>
		<xsl:otherwise>
		  <xsl:copy-of select="tokenize('a b c', ' ')[1]"/>
		</xsl:otherwise>
	  </xsl:choose>

which runs fine in saxon but even though xalan wouldn't have to run
the tokenize function, it still
thinks there's a mistake because it doesn't recognize the function
tokenize.  I think that xalan
would be convinced that everything was OK if tokenize was prefixed by
a namespace.  Is it
possible to assign a namespace to XSLT2 functions so that I could say
something like...

	  <xsl:choose>
		<xsl:when test="function-available(str:split)">
		  <xsl:copy-of select="str:split('a b c', ' ')[1]"/>
		</xsl:when>
		<xsl:otherwise>
		  <xsl:copy-of select="xslt2:tokenize('a b c', ' ')[1]"/>
		</xsl:otherwise>
	  </xsl:choose>

Does anyone else have any other ideas?

Cheers,
Andy

-- 
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Andy Chambers
Formedix Ltd