Hi Mike,
  I tried your solution, and it was producing something different than
with the OP wanted.

The following stylesheet works ...

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

<xsl:output method="xml" indent="yes" />

<xsl:template match="Objs">
  <xsl:variable name="temp">
    <xsl:apply-templates select="obj[not(@name = ../obj/@child)]" />
  </xsl:variable>
  <xsl:call-template name="processTemp">
    <xsl:with-param name="temp" select="$temp/*" />
  </xsl:call-template>
</xsl:template>

<xsl:template match="obj">
  <xsl:variable name="child" select="@child" />
  <Obj name="{@name}">
    <xsl:choose>
      <xsl:when test="../obj[@name = $child]">
        <xsl:apply-templates select="../obj[@name = $child]" />
      </xsl:when>
      <xsl:otherwise>
        <Obj name="{$child}" />
      </xsl:otherwise>
    </xsl:choose>
  </Obj>
</xsl:template>

<xsl:template name="processTemp">
  <xsl:param name="temp" />

  <xsl:for-each-group select="$temp" group-by="@name">
    <Obj name="{@name}">
      <xsl:call-template name="processTemp">
        <xsl:with-param name="temp" select="current-group()/*" />
      </xsl:call-template>
    </Obj>
  </xsl:for-each-group>

</xsl:template>

</xsl:stylesheet>

On Fri, Aug 8, 2008 at 1:46 PM, Michael Kay <mike@xxxxxxxxxxxx> wrote:
>
> Do this as a standard recursive descent of the input tree using
> xsl:apply-templates, but with one exception: instead of processing the
> physical XML children, you process the logical children selected using the
> foreign key relationship.
>
> Usually in this problem elements have a pointer to their parent node, in
> your case you have a pointer to each of the children, which makes it a
> little more difficult, but not much.
>
> <xsl:key name="nameKey" match="obj" use="@name"/>
>
> <xsl:template match="obj">
>  <Obj name="@name">
>    <xsl:for-each select="key('nameKey', @name)">
>      <xsl:apply-templates select="key('nameKey', @child)"/>
>    </xsl:for-each>
>  </Obj>
> </xsl:template>
>
> Or you could condense it:
>
> <xsl:template match="obj">
>  <Obj name="@name">
>      <xsl:apply-templates select="key('nameKey', @name)/key('nameKey',
> @child)"/>
>  </Obj>
> </xsl:template>
>
> but I thought that might be a bit confusing!
>
> Of course, you have to start by calling apply-templates on the "logical
> root" of the tree.
>
> Michael Kay
> http://www.saxonica.com/


-- 
Regards,
Mukul Gandhi