XSLT 2.0 and Grouping

A common grouping use case that I did not see, is one wherein an input
like:

<table>
<tr>
<td>a</td>
<td>b</td>
<td>c</td>
</tr>
<tr>
<td>a</td>
<td>b</td>
<td>c1</td>
</tr>
<tr>
<td>a</td>
<td>b1</td>
<td>c2</td>
</tr>
</table>

is transformed into

<table>
<tr>
<td rowspan="3">a</td>
<td rowspan="2">b</td>
<td>c</td>
</tr>
<tr>
<td>c1</td>
</tr>
<tr>
<td>b1</td>
<td>c2</td>
</tr>
</table>

This is currently very awkward in XSLT -- and at least with my XSLT
skills has poor performance characteristics.....

--
Jess Holle
jessh@ptc.com