AnyValEnumTest.scala

/**
 * A command ID for SMPP
 */

trait FieldHelpers {

  val className = getClass.getName.dropRight(1)

  val missingLabel = "unknown"

  // fragile. also, needs to be lazy for initialization order.
  lazy val names = getClass.getMethods.toList.filter(m => m.getParameterTypes.isEmpty
    && m.getReturnType == classOf[Int] && m.getName != "hashCode").map(m =>
    m.invoke(this).asInstanceOf[Int] -> m.getName).toMap

  def fieldName(v: Int): String = {
    val fieldName = names.getOrElse(v, missingLabel)
    f"$className.$fieldName(0x$v%x)"
  }
}

class CommandId(val intValue: Int) extends AnyVal {
  override def toString(): String = {
    CommandId.fieldName(intValue)
  }
}

object CommandId extends FieldHelpers {
  val generic_nack = new CommandId(0x80000000)
  val bind_receiver = new CommandId(0x00000001)
  val bind_receiver_resp = new CommandId(0x80000001)
  val bind_transmitter = new CommandId(0x00000002)
  val bind_transmitter_resp = new CommandId(0x80000002)
  val query_sm = new CommandId(0x00000003)
  val query_sm_resp = new CommandId(0x80000003)
  val submit_sm = new CommandId(0x00000004)
  val submit_sm_resp = new CommandId(0x80000004)
}

object Demo extends App {

  println(CommandId.generic_nack)
  println(new CommandId(100))
  /*
    CommandId.generic_nack(0x80000000)
    CommandId.unknown(0x64)
  */
}