title: How to filter for named branches with a partial name match in mercurial?
body: <p>I use the following search expression to find all the heads which aren't closed in our mercurial repository:</p>
  
  <pre><code>head() and not closed() and not branch('default') 
  </code></pre>
  
  <p>However, I have a convention to name feature branches as <code>fb-(target-release)-(feature-name)</code> and I'd also like to filter for the named branches which contain <code>fb</code> <strong>at the beginning of their name</strong>. Is this possible without piping the output to another application?</p>