convert function to partial function scala

Question

I have a sealed trait:

sealed trait ActorMessage
case class AddX(x: Int) extends ActorMessage
case class RemoveX(x: Int) extends ActorMessage

Also I have a function to handle all messages and warn me about non exhaustive match:

def handleMessage: ActorMessage => Unit = {
  case AddX(x) => ...
  case RemoveX(x) => ...
}

Actor requires a PartialFunction[Any, Unit]. PartialFunction extends Function which means I can't assign my Function to be PartialFunction.

I have written simple converter:

def liftToPartialFunction[FUND <: PFUND, B, PFUND](f: Function[FUND, B]): PartialFunction[PFUND, B] = new PartialFunction[PFUND, B] {
  override def isDefinedAt(x: PFUND): Boolean = x.isInstanceOf[FUND]
  override def apply(v1: PFUND): B = f(v1.asInstanceOf[FUND])
}

But is there a better way to do this? Or is there any equivalent in standard scala library?

Answer 1

I usually do something like this:

override def receive = {
  case m: ActorMessage => m match {
    // You'll get non-exhaustive match warnings here
    case AddX(x) => /* ... */
    case RemoveX(x) => /* ... */
  }
  case m => /* log a warning */
}

Equivalently, using your handleMessage function:

override def receive = {
  case m: ActorMessage => handleMessage(m)
  case m => /* log a warning */
}