XML/XSLT stylesheet/reverse

subsequence and reverse

File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<favorite-books>
  <booklist>
    <book isbn="1111111111" 
      favorite="f1">XSLT</book>
    <book isbn="2222222222" 
      favorite="A">Java</book>
    <book isbn="3333333333" 
      favorite="A">C++</book>
    <book isbn="4444444444" 
      favorite="f1">SQL</book>
    <book isbn="5555555555" 
      favorite="B">Oracle</book>
    <book isbn="0375724443" 
      favorite="B">XML</book>
  </booklist>
</favorite-books>

File: Transform.xslt

<?xml version="1.0"?>
<xsl:stylesheet version="2.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  
  <xsl:output method="text"/>
 
  <xsl:variable name="A-List" as="node()*">
    <xsl:sequence 
      select="/favorite-books/booklist
              /book[contains(@favorite, "A")]"/>
  </xsl:variable>
  <xsl:variable name="B-List" as="node()*">
    <xsl:sequence 
      select="/favorite-books/booklist
              /book[contains(@favorite, "B")]"/>
  </xsl:variable>
  <xsl:template match="/">
    <xsl:value-of 
      select="if (subsequence($A-List, 1, 1) is 
                  subsequence($B-List, 1, 1))
              then "    The first nodes are the same!&#xA;"
              else "    The first nodes aren""t the same!&#xA;""/>
    
    <xsl:value-of 
      select="if (subsequence($A-List, 1, 1) is
                  subsequence(reverse($B-List), 1, 1))
              then "    The first nodes are the same!&#xA;"
              else "    The first nodes aren""t the same!&#xA;""/>
  </xsl:template>
</xsl:stylesheet>
Output:
    The first nodes aren"t the same!
    The first nodes aren"t the same!