object Timing {
  /** Return a tuple, where the first part is the milliseconds
    * taken and the second part is the result of the block
    * execution. */
  def time[R](block: =>R): (Long, R) = {
    val start = System.currentTimeMillis
    val result = block
    (System.currentTimeMillis - start, result)
  }

  /** Execute the block and pass the time taken to the handler. */
  def time[R](block: =>R, handler: Long=>Any): R = {
    val (ms, result) = time(block)
    handler(ms)
    result
  }

  /** Execute the command and print the time taken. */
  def printTime[R](block: =>R) {
    time(block, println)
  }

  /** A class to store timing statistics. */
  class Stats(val total: Long, val max: Long, val min: Long, val avg: Long) {
    override def toString =
      "total: " + total + "ms,  min: " + min +
      "ms,  max: " + max + "ms,  avg: " + avg + "ms"
  }

  /** Execute the blocks and report statistics about the time taken. */
  def speedTest(executions: List[() => Any]) {
    val times = executions.map(e => time({ e () })._1)

    val total = times.reduce(_+_)
    val max = times.reduce(math.max(_, _))
    val min = times.reduce(math.min(_, _))
    val avg = total / executions.size

    new Stats(total, max, min, avg)
  }
}