title: nginx using OR set at regex for the map
body: <p>I'm trying to write a map for my website and it's working great:</p>
  
  <pre><code>map $request_uri $redirect_uri {
    /en/oldname    /en/newname;
    /de/oldname    /de/newname;
    /fr/oldname    /fr/newname;
  }
  </code></pre>
  
  <p>until I try to implement some regex, something like this:</p>
  
  <pre><code>map $request_uri $redirect_uri {
    /(?&lt;lang&gt;(en|de|fr))/oldname    /$lang/newname;
  }
  </code></pre>
  
  <p>The map above is not working, and due to the lack of debugging knowledge - I'm unable to know why. Even the basic regex (without using named captures) is not working for me:</p>
  
  <pre><code>map $request_uri $redirect_uri {
    /(en|de|fr)/oldname    /en/newname;
  }
  </code></pre>
  
  <p>nginx 1.10.3</p>
  
  <p>Please help me to figure out what am I doing wrong?</p>