dwhitney

class Account(val accountNo: String, beginningBalance: Int){
  private var _balance = beginningBalance
  def balance = this.synchronized{ _balance }
  def credit(amount: Int) = this.synchronized{ _balance = _balance + amount }
  def debit(amount: Int) = this.synchronized { _balance = _balance - amount }
}

object Bank{
        
  val accounts = Map("from" -> new Account("from", 500), "to" -> new Account("to", 500) )

dwhitney

  def main(args: Array[String]): Unit = {
    import java.util.concurrent._
    import scala.util.Random._
    val executor = Executors.newFixedThreadPool(2)
    for(_ <- 1 to 10000){
      executor.submit(new Runnable(){
        def run = {
          if(nextInt(2) % 2 == 0) Bank.transfer("from", "to", nextInt(50))
          else Bank.transfer("to", "from", nextInt(50))
        }

dwhitney

class Account(val accountNo: String, var balance: Int){
  def credit(amount: Int) = balance = balance + amount
  def debit(amount: Int) = balance = balance - amount
}

object Bank{
        
  val accounts = Map("from" -> new Account("from", 500), "to" -> new Account("to", 500) )

  def transfer(fromNo: String, toNo: String, amount: Int): Unit = {

dwhitney

object Circle{
  def circleAtOrigin = Circle(0, 0, _: Double)
}
case class Circle(x: Double, y: Double, radius: Double)

dwhitney

def fiftyCircle = Circle(_:Double, _:Double, 50)

dwhitney

object Rectangle{
  def rectangleAtOrigin = new Rectangle(0, 0, _: Double, _:Double)
}
class Rectangle(x1: Double, y1: Double, x2: Double, y2: Double)

dwhitney

circleAtOrigin(25)

dwhitney

def circleAtOrigin = Circle(0, 0, _: Double)

dwhitney

object Circle{
  def circleAtOrigin = Circle(0, 0, _: Double)
}

case class Circle(x: Double, y: Double, radius: Double)

dwhitney

case class CircleAtOrigin(override val radius: Double) extends Circle(0, 0, radius)