Re: Combining segments by matching attributes

<group>
  <text xml:id="A15">
    <seg n="220.2">...</seg>
    <seg n="220.3">...</seg>
    (etc.)
  </text>
  <text xml:id="B15">
    <seg n="220.2">...</seg>
    <seg n="220.3">...</seg>
    (etc.)
  </text>
</group>

The texts may or may not have all the same segments (so text A may
have seg[@n='223.1'] and text B may not, or vice versa). In addition
the numbers are not unique to each segment (there may be several segs
in a row with the same number).

Given this, I would like to generate a file that pulls together the
like segments from each text, resulting in something that looks like
this:

<app>
  <rdg wit="#A15"><seg n="220.2">...</seg></rdg>
  <rdg wit="#B15><seg n="220.2">...</seg></rdg>
  (etc.)
</app>
<app>
  <rdg wit="#A15"><seg n="220.3">...</seg></rdg>
  <rdg wit="#B15><seg n="220.3">...</seg></rdg>
  (etc.)
</app>
<app>
  <!-- for example, A15 lacks seg[@n='223.1'] -->
  <rdg wit="#B15"><seg n="223.1">...</seg></rdg>
  (etc.)
</app>

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="2.0">

  <xsl:template match="/">
    <xsl:for-each-group select="group/text/seg" group-by="@n">
      <app>
        <xsl:apply-templates select="current-group()"/>
      </app>
    </xsl:for-each-group>
  </xsl:template>

  <xsl:template match="seg">
    <reg wit="#{../@xml:id}">
      <xsl:copy-of select="."/>
    </reg>
  </xsl:template>

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/