ImperativePong.scala

package pong.imperative
    
sealed trait Event

class PongConnection {
  def isConnected(): Boolean = sys.error("not implemented")
  def readEvent(): Event     = sys.error("not implemented")
  def moveUp(): Unit         = sys.error("not implemented")
  def moveDown(): Unit       = sys.error("not implemented")
  def shootMissile(): Unit   = sys.error("not implemented")
} 

class Bot(connection: PongConnection) {
  var myDirection      = 0
  var missileInventory = 0
  var enemyPosition    = 0

  def update(event: Event) {
    if (conditionA(event)) {
      goUp()
    } else if (conditionB(event)) {
      shootMissile()
    }
  } 
  
  private def goUp() {
    myDirection = 1
    connection.moveUp()      
  }
  
  private def shootMissile() {
    missileInventory -= 1
    connection.shootMissile()
  }
  
  private def conditionA(event: Event): Boolean = sys.error("not implemented")
  private def conditionB(event: Event): Boolean = sys.error("not implemented")
} 
    
object Pong extends App {
  val connection = new PongConnection
  val bot        = new Bot(connection)
  while (connection.isConnected()) {
    val event = connection.readEvent()
    bot.update(event)
  }
}