title: Swift ENUM how to convert "rawValue" back to Enum case?
body: <p>I have an enum:</p>
  
  <pre><code>  enum  switch : String {
        case on = "powerOn"
        case off = "powerOff"
        var japanswitch : String {
            case .on : return "onpu"
            case .off : return "offu"
        }
    }
  </code></pre>
  
  <p>In my code my function passed down "powerOn" as pure string parameter.  The problem is some point of my function require to translate "powerOn" to japanswitch.</p>
  
  <p>But problem is "powerOn" right now is nothing more than a mere String which has no relationship to japanswitch at all.</p>
  
  <p>How do I translate "powerOn" to japanswitch? The desired result should be "onpu".</p>