[xsl] On XSLT 2.0 Writing Styles

["Dimitre Novatchev" <dnovatchev@xxxxxxxxx>]

In XSLT 2.0 the programmer has the choice to write the same code in two
different styles as below:

func-dvc-foldl.xsl:
=============
<xsl:stylesheet version="2.0"
 xmlns:f="http://fxsl.sf.net/";
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
 exclude-result-prefixes="f">

    <xsl:import href="func-apply.xsl"/>

    <xsl:function name="f:foldl">
      <xsl:param name="pFunc" as="element()"/>
      <xsl:param name="pA0"/>
      <xsl:param name="pList" as="item()*"/>

      <xsl:sequence select=
       "if(empty($pList))
          then
             $pA0
          else
             for $vcntList in count($pList) return
               if($vcntList = 1)
                  then
                     f:apply($pFunc, $pA0, $pList[1])
                  else
                     for $vHalfLen in floor($vcntList div 2) return
                       f:foldl($pFunc,
                             f:foldl($pFunc, $pA0, $pList[position() &lt;=
$vHalfLen]),
                             $pList[position() > $vHalfLen]
                             )"/>

    </xsl:function>

</xsl:stylesheet>


and


func-dvc-foldl-oldStyle.xsl:
===================
<xsl:stylesheet version="2.0"
 xmlns:f="http://fxsl.sf.net/";
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
 exclude-result-prefixes="f">

    <xsl:import href="func-apply.xsl"/>

    <xsl:function name="f:foldl">
      <xsl:param name="pFunc" as="element()"/>
      <xsl:param name="pA0"/>
      <xsl:param name="pList" as="item()*"/>

      <xsl:choose>
         <xsl:when test="not($pList)">
            <xsl:copy-of select="$pA0"/>
         </xsl:when>
         <xsl:otherwise>
            <xsl:variable name="vcntList" select="count($pList)"/>
            <xsl:choose>
              <xsl:when test="$vcntList = 1">
                <xsl:sequence select="f:apply($pFunc,$pA0, $pList[1])"/>
              </xsl:when>
              <xsl:otherwise>
                <xsl:variable name="vHalfLen"
                              select="floor($vcntList div 2)"/>

                <xsl:sequence select=
                "f:foldl($pFunc,
                         f:foldl($pFunc, $pA0, $pList[position() &lt;=
$vHalfLen]),
                         $pList[position() > $vHalfLen]
                         )"/>
              </xsl:otherwise>
            </xsl:choose>
         </xsl:otherwise>
      </xsl:choose>
    </xsl:function>
</xsl:stylesheet>


Which one of these two styles should be preferred?

What are the advantages and shortcomings of each style regarding
readability, compactness, flexibility, efficiency and maintainability?

Ideally, there should be an agreement (consensus) on the answers to
questions like these and one should be able to find such answers easily in
the archives and the FAQ.

=====
Cheers,

Dimitre Novatchev.
http://fxsl.sourceforge.net/ -- the home of FXSL




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