title: scala list type mismatch
body: <p>So I had list of tuples like this:</p>
  
  <pre><code>val rooms = List(("Hi", "mom"),("hi", "dad"))
  val foo = rooms.map(arg =&gt;{
                    var fields = List
                      ( new JField("greeting",arg._1),
                        new JField("recipient",arg._2))
                        new JObject(fields)})
  </code></pre>
  
  <p>And there was much happiness in the land, but when I changed list of room like so:</p>
  
  <pre><code>case class Room(greeting:String, recipient:String)
  val rooms = List(Room("Hi", "mom"),Room("hi", "dad"))
  val foo = rooms.map(arg =&gt;{
                    var fields = List
                      ( new JField("greeting",arg.greeting),
                        new JField("recipient",arg.recipient))
                        new JObject(fields)})
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>[error] &lt;file&gt;: type mismatch;
  [error]  found   : scala.collection.immutable.List.type (with underlying type object List)
  [error]  required: List[blueeyes.json.JsonAST.JValue]
  [error]                       new JArray(fields)
  </code></pre>
  
  <p>So it appears that the list is now of Object instead of JField as it was before, why is that?</p>