title: How to convert from String to Int in Json.Decoder
body: <p>Here's my decoder:</p>
  
  <pre><code>decodeData : Json.Decoder (Id, String)
  decodeData =
    Json.at ["data", "0"]
      &lt;| Json.object2 (,)
        ("id" := Json.int)
        ("label" := Json.string)
  </code></pre>
  
  <p>The <code>id</code> should logically be <code>Int</code> however my backend sends it as <code>String</code> (e.g. we get <code>"1"</code> instead of <code>1</code>). </p>
  
  <p>How can I cast the decoded value to <code>Int</code>?</p>