XML / XSL

<xsl:template name="DeDupe">
    <xsl:param name="list" />
    <xsl:param name="sep" select="', '" />

    <xsl:for-each select="$list">
        <xsl:variable name="curr" select="string(.)" />
        <xsl:variable name="i" select="position()" />

        <xsl:choose>
            <xsl:when test="count($list[$i > position() and string(.) = $curr]) > 0" />
            <xsl:otherwise>
                <xsl:if test="position() != 1"><xsl:copy-of select="$sep" /></xsl:if>
                <xsl:value-of select="$curr" />
            </xsl:otherwise>
        </xsl:choose>
    </xsl:for-each>
</xsl:template>

...

<xsl:call-template name="DeDupe">
    <xsl:with-param name="list" select="XPath expression" />
</xsl:call-template>

<xsl:template name="ListItems">
    <xsl:param name="list" />
    <xsl:param name="name" />
    
    <xsl:for-each select="$list[contains(@name, $name)]">
        <-- Do something here -->
    </xsl:for-each>
</xsl:template>
...
<xsl:call-template name="ListItems">
    <xsl:with-param name="list" select="XPath expression" />
    <xsl:with-param name="name" select="'M:XMLObject:functionname'" />
</xsl:call-template>

var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.4.0");<br />
xmlDoc.async = false;<br />
xmlDoc.validateOnParse = true;<br />
xmlDoc.load("books.xml");

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
  <xs:element name="CarEngineComponent">
    <xs:complexType mixed="true">
      <xs:choice minOccurs="0" maxOccurs="unbounded">
        <xs:element ref="CarEngineComponent"/>
      </xs:choice>
    </xs:complexType>
  </xs:element>
</xs:schema>