title: How to write your own matcher in Circumflex?
body: <p>As asked <a href="https://stackoverflow.com/q/6641864/35189">here</a>, I need to run a Circumflex action only if a condition is met. Currently, I do it like this:</p>
  
  <pre><code>get("/") = requireLogin {
      ...
  }
  </code></pre>
  
  <p>Now Circumflex supports Matchers, which can be put right within the <code>get()</code> specification:</p>
  
  <pre><code>get("/mail" &amp; Host("localhost"))
  </code></pre>
  
  <p>How can I write my own matcher, so the above <code>requireLogin</code> gets closer to the Circumflex style? I wish to write something like this:</p>
  
  <pre><code>get("/" &amp; IsLoggedIn) = {
      ...
  }
  </code></pre>