title: RESTful design of convert, calculate
body: <p>How to design operations like:</p>
  
  <ul>
  <li>calculate</li>
  <li>convert</li>
  <li>translate</li>
  </ul>
  
  <p>For example: convert from "EUR" to "CNY" amount "100".</p>
  
  <p>Is this <code>/convert?from=EUR&amp;to=CNY&amp;amount=100</code> RESTful ?</p>