title: Parsing JSON 'NaN' value in Go
body: <p>When I try and unmarshal this JSON object from the Microsoft Web Ngram API:</p>
  
  <pre class="lang-js prettyprint-override"><code>{"backoff": NaN, "cookie": "", "probabilities": [], "words": []}
  </code></pre>
  
  <p>I get the error: "invalid character 'N' looking for beginning of value"</p>
  
  <p>I know that NaN isn't valid JSON but the data isn't mine and I need a way to parse it. 
  Is there any easy way to do this in Go?</p>