object-perf-test2.scala

// reporting library
// http://stackoverflow.com/questions/9160001/how-to-profile-methods-in-scala

def perf[R](block: => R): Unit = {
  val t0 = System.nanoTime()
  block
  val t1 = System.nanoTime()

  val elapsed = (t1 - t0) / 1000000000f
  println("Elapsed time: " + elapsed + "s")
}

// setup code

case class ValidatedPostalCode(code: String, plus4: Option[String] = None) {
  val numericCode = code.toInt
  require(numericCode > 0)
  require(numericCode < 99999)

  plus4.map { pf =>
    val numericPlus4 = pf.toInt
    require(numericPlus4 > 0)
    require(numericPlus4 < 9999)
  }

  override def toString = {
    code + plus4.map(pf => "-" + pf).mkString
  }
}

case class PostalCode(code: String, plus4: Option[String] = None) {
  override def toString = {
    code + plus4.map(pf => "-" + pf).mkString
  }
}

// tests

def test1 = {
  def doStuff(postalCode: String) = for(_ <- 1 to 1000000) "You live at " + postalCode
  perf {
    doStuff("12345-1234")
  }
}

def test2 = {
  def doStuff(postalCode: PostalCode) = for(_ <- 1 to 1000000) "You live at " + postalCode
  perf{
    doStuff(new PostalCode("12345", Some("1234")))
  }
}

def test3 = {
  def doStuff(postalCode: ValidatedPostalCode) = for(_ <- 1 to 1000000) "You live at " + postalCode
  perf{
    doStuff(new ValidatedPostalCode("12345", Some("1234")))
  }
}

// run tests

test1
test2
test3