gistfile1.java

object Profiler {
  def apply[A](report: Long => Unit)(fun: => A): A = {
    val start = System.currentTimeMillis()
    val result = fun
    val time = System.currentTimeMillis() - start
    report(time)
    result
  }

  def PrintProfiler[A](fun: => A) =
    apply((t: Long) => println("Execution time: " + t + "ms"))(fun)
}

object Demo {
  import Profiler.PrintProfiler

  def test(): Int = { Thread.sleep(1000); 123 }

  def main(args: Array[String]): Unit = {
    val res = PrintProfiler(test)
    println("Result: " + res)

    Profiler((t: Long) => println("Execution time: " + t + "ms")) {
      Thread.sleep(500)
    }

    PrintProfiler {
      Thread.sleep(200)
    }
  }
}