[xslt2] matching matches

Hi :)

I'm writing an XSLT2 transformation to go from a code listing such as

[...]
007     <title>Sirup</title>
[...]

to something like this:
(output of current state of the templates)

[...]
007     <span class="tag">&lt;<span 
class="tagname">title</span>&gt;</span>Sirup<span class="tag">&lt;/<span 
class="tagname">title</span>&gt;</span>
[...]

The code listings get marked up, so that I can so syntax highlighting 
via CSS.
I'm using Saxon 7.3.1.

Now I want to markup the attributes, as .attribute_name and 
.attribute_value. What I'm trying now is to call a second template with 
the string that consists of all the attributes, to get a marked up 
version returned. But somehow the match is not passed to the second 
template. Any help appreciated :)
##### (all regexen etc are unfinished) #####
<t:template match="code[(_at_)class='screen']">
  <t:copy>
    <t:for-each select="@*">
      <t:copy/>
    </t:for-each>
    <t:analyze-string select="."
      regex="&lt;(\/?)([^\s&gt;\!]+)([^&gt;]+)?&gt;">
      <t:matching-substring>
        <span class="tag">
          <t:text>&lt;</t:text>
          <t:value-of select="regex-group(1)"/>
          <span class="tagname">
            <t:value-of select="regex-group(2)"/>
          </span>
          <!--
          returns all attributes, not marked up
          <t:value-of select="regex-group(3)"/>
          -->
<!--
  <t:message>
regex-group(3): <t:value-of select="regex-group(3)"/>
</t:message>
          -->
          <!-- nothing gets returned here :| -->
          <t:call-template name="markup_attributes">
            <with-param name="input"
              select="regex-group(3)"/>
          </t:call-template>
          <t:text>&gt;</t:text>
        </span>
      </t:matching-substring>
      <t:non-matching-substring>
        <t:value-of select="."/>
      </t:non-matching-substring>
    </t:analyze-string>
  </t:copy>
</t:template>

<t:template name="markup_attributes">
  <t:param name="input"/>
  <!--
<t:message>
$input: <t:value-of select="$input"/>
</t:message>
-->
    <t:analyze-string select="$input"
      regex="\s+([^=]+)=">
      <t:matching-substring>
        <span class="attribute_name">
          <t:value-of select="regex-group(1)"/>
          <t:text>=</t:text>
        </span>
      </t:matching-substring>
      <t:non-matching-substring>
        <t:value-of select="."/>
      </t:non-matching-substring>
    </t:analyze-string>
</t:template>
##### (end) #####

Tobi

--
http://www.pinkjuice.com/


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