[xsl] Generating implicit wrapper element

[Ferdinand Soethe <xsl-list@xxxxxxxxxx>]

I have a question about the problem below which has already been
identified as a 'positional grouping problem'. (I think) I understand
the Muenchian method-based solutions suggested (at least in theory).

What I don't understand is what is wrong about using the following simple
solution that I pieced together from different postings:

<xsl:template match="li">
    <xsl:if test="(name(preceding-sibling::*[1])!='li' )">
        <xsl:text disable-output-escaping="yes">&lt;ul&gt;</xsl:text>
    </xsl:if>
    <li><xsl:copy-of select="@*"/><xsl:apply-templates/></li>
    <xsl:if test="(name(following-sibling::*[1])!='li' )">
        <xsl:text disable-output-escaping="yes">&lt;/ul&gt;</xsl:text>
    </xsl:if>
  </xsl:template>

Seems like it fits much better into my context of using
'apply-templates' as much as possible (no need to process all li's at
once and ignore them later) and - except for that hack of
smuggling half the ul-element into my output - it also seems quite
reasonable xsl, not?

Your input much appreciated,

--
Ferdinand Soethe


--- The problem ---

I have an XML-document with paragraphs and list items that have no
wrapper element around each list.

Something like this:

<par>my first para</par>
<par>second para</par>
<li>first list item of first list</li>
<li>second list item of first list</li>
<li>third list item of first list</li>
<par>third para</par>
<li>first list item of second list</li>
<par>fourth para</par>
<li>first list item of third list</li>
<li>second list item of third list</li>

In my transformation I would like to add these implicit wrapper
element around each of the list to get something like

<p>my first para</p>
<p>second para</p>
<ul>
<li>first list item of first list</li>
<li>second list item of first list</li>
<li>third list item of first list</li>
</ul>
<p>third para</p>
<ul>
<li>first list item of second list</li>
</ul>
<p>fourth para</p>
<ul>
<li>first list item of third list</li>
<li>second list item of third list</li>
</ul>