[xsl] questions regarding array implementation

[Kenneth Stephen <marvin.the.cynical.robot@xxxxxxxxx>]

Hi,

    I've used RTF's to implement arrays in XSLT. The implementaion is
shown below. With respect to that, I have a couple of questions that I
hope someone will answer :

1.  To my mind, the most significant difference between arrays and
lists are that the access times for any two elements in the array are
the same. When viewed from the XSL level, my implementation seems to
satisfy that condition. However, since RTF's are being used in the
implementation, the question would become : "when using XPath
expressions to select from within the fragment, will the access time
for any two elements at the same level of nesting be the same?". Would
the answer to this be dependant on the XSL processor chosen, or is
there something fundamental in the language which causes the answer to
my question to be the same regardless of the processor?

2.  Is there a better / more efficient way of implementing this under XSL 2.0?

Thanks in advance,
Kenneth

-----------------------  Implementation  ----------------------------

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
	xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
	xmlns:xalan="http://xml.apache.org/xalan";
	xmlns:array="urn:internal:dummy:namespace"
	exclude-result-prefixes="array">


	<xsl:template name="addElement">
		<xsl:param name="array" />	<!-- will not be present in the
invocation when adding first element -->
		<xsl:param name="element" />
		
		<xsl:variable name="arrayNodes" select="xalan:nodeset($array)" />
		<xsl:element name="root" namespace="urn:internal:dummy:namespace">
			<xsl:if test="count($arrayNodes/array:root/*) != 0">
				<xsl:for-each select="$arrayNodes/array:root/array:item[position()
&gt;= 1 and
						position() &lt;= count($arrayNodes/array:root/array:item)]">
					<xsl:copy-of select="." />
				</xsl:for-each>
			</xsl:if>
			<xsl:element name="item" namespace="urn:internal:dummy:namespace">
				<xsl:copy-of select="$element" />
			</xsl:element>
		</xsl:element>
	</xsl:template>

	<xsl:template name="getElementAt">
		<xsl:param name="array" />
		<xsl:param name="index" />
		
		<xsl:variable name="itemFragment"
select="xalan:nodeset($array)/array:root/array:item[$index]" />
		<xsl:choose>
			<xsl:when test="$itemFragment/*">
				<xsl:copy-of select="$itemFragment/*" />
			</xsl:when>
			<xsl:otherwise>
				<xsl:value-of select="$itemFragment" />
			</xsl:otherwise>
		</xsl:choose>
	</xsl:template>
		
	<xsl:template match="/">
		<xsl:variable name="arrayVar">
			<xsl:call-template name="addElement"> <!-- add first element -->
				<xsl:with-param name="element" select="1" />
			</xsl:call-template>
		</xsl:variable>
		<xsl:variable name="arrayWithThreeItemsInIt">
			<xsl:call-template name="addElement"> <!-- add third element -->
				<xsl:with-param name="array">
					<xsl:call-template name="addElement"> <!-- add second element -->
						<xsl:with-param name="array" select="$arrayVar" />
						<xsl:with-param name="element" select="2" />
					</xsl:call-template>
				</xsl:with-param>
				<xsl:with-param name="element" select="$arrayVar" />
			</xsl:call-template>
		</xsl:variable>
		<xsl:call-template name="getElementAt">
			<xsl:with-param name="array" select="$arrayWithThreeItemsInIt" />
			<xsl:with-param name="index" select="2" />
		</xsl:call-template>
	</xsl:template>
	
</xsl:stylesheet>