[xsl] tail-recursion

Subject: [xsl] tail-recursion
From: "I-Lin Kuo" <ikuoikuo@xxxxxxxxxxx>
Date: Thu, 28 Aug 2003 09:43:36 -0400
I have to do some string manipulation. The following takes a string such as "1~2~a~!~f~4~5~!~1~2~3" and parses it as a list delimited by "~!~" and then processes each list element "1~2~a", "f~4~5", and "1~2~3" as a list delimited by "~" in order to display as an html table

<xsl:template name="parseRows">
<xsl:param name="catContents"/>
<xsl:param name="font-size" select="'-1'"/>
<xsl:when test="contains($catContents,'~!~')">
<xsl:call-template name="parseRow">
<xsl:with-param name="rowContents" select="substring-before($catContents,'~!~')"/>
<xsl:with-param name="font-size" select="$font-size"/>
<xsl:call-template name="parseRows">
<xsl:with-param name="catContents" select="substring-after($catContents,'~!~')"/>
<xsl:with-param name="font-size" select="$font-size"/>
<xsl:value-of select="$catContents"/>

<xsl:template name="parseRow">
	<xsl:param name="rowContents"/>
	<xsl:param name="font-size" select="'-1'"/>
		<xsl:for-each select="xalan:tokenize($rowContents,'~')">
			<td><font size="{$font-size}"><xsl:value-of select="."/></font></td>

This code works, but I'm thinking of modifying it. I know that some xslt engines use tail recursion to optimise their processing and I'm worried about breaking that.

1. Which xslt engines use tail recursion?
2. I'm not exactly sure about tail recursion. Does my xslt above already violate that? If not, what should I be careful about.
3. Is there a way for me to empirically test whether an xslt engine uses tail recursion?

I-Lin Kuo, Ann Arbor, MI
Macromedia Certified ColdFusion 5.0 Advanced Developer
Sun Certified Java 2 Programmer
Ann Arbor Java Users Group (www.aajug.org) SUN Top 25 JUG

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