title: struct and error syntax with erlang
body: <p>I want to know the use of struct and error with erlang</p>
  
  <p>for example I have problem to understand this syntax</p>
  
  <pre><code>{error, bad_amount} -&gt; {struct, [{"status", "error"}, {"reason", "badamount"}]};
  </code></pre>
  
  <p>best regard
  batista</p>