gistfile1.txt

object Looping {
  val l = 1000
  val l2 = l * l
  val l3 = l * l * l
  
  def main(args: Array[String]): Unit = {
    warmup()
    measure()
  }
  
  def warmup(): Unit = {
    new IntCountUpSum().f(l3)
    new LongCountUpSum().f(l3)
    // new TwoIntLoops().f(l2, l)
  }
  
  def measure(): Unit = {
    Timer(new IntCountUpSum().f(l3))
    Timer(new LongCountUpSum().f(l3))
    // Timer(new TwoIntLoops().f(l2, l))
  }
}

class IntCountUpSum {
  import For.cfor
  
  def f(n: Int) = {
    var sum = 0
    
    cfor[Int](0, _ < n, _ + 1)(i => {
      sum += i
    })
    
    sum
  }
}

class LongCountUpSum {
  import For.cfor
  
  def f(n: Long) = {
    var sum = 0L
    
    cfor[Long](0L, _ < n, _ + 1L)(i => {
      sum += i
    })
    
    sum
  }
}

class TwoIntLoops {
  import For.cfor
  
  def f(n: Int, o: Int) = {
    val r = n / math.sqrt(o)
    val max = (o * (o + 1) / 2) * (r / 3) / 2
    
    var sum = 0
    
    cfor[Int](0, a => a < r && sum < max, _ + 3)(i => {
      cfor[Int](o, _ > 0, _ - 1)(j => {
        sum += j
      })
    })
    
    sum
  }
}

object For {
  def cfor[@specialized A](zero: A, okay: A => Boolean, inc: A => A)(act: A => Unit) = {
    var i = zero
    while (okay(i)) {
      act(i)
      i = inc(i)
    }
  }
}

object Timer {
  import scala.compat.Platform
  import java.util.Locale

  def apply(functionToMeasure: => Any) : Unit = {
    val before = System.nanoTime
    val result = functionToMeasure
    val after = System.nanoTime
    println("Result: " + result.toString)
    println("Execution took %.3f ms.".format((after - before).toDouble * 1e-6d))
  }
}//