App.scala

import Benchmark._

object App {
    def main(args: Array[String]): Unit = {
        benchmark(100000){
            report("foo"){ foo() } ::
            report("bar"){ bar() } ::
            Nil
        }
    }
}

Benchmark.scala

object Benchmark {
    case class BenchmarkReport(name: String, f: () => Unit){
        def run(n: Int) = {
            val start = System.currentTimeMillis
            (1 to n) foreach { i => f() }
            val time = System.currentTimeMillis - start
            (name, time)
        }
    }
    
    def benchmark(n: Int)(reports: List[BenchmarkReport]) = {
        val results = reports.map(_.run(n))
        println("Name                    Time(s)")
        println("===============================")
        results.foreach { case (name, time) =>
            printf("%-20s %10f\n", name, time / 1000.0)
        }
        results
    }
    
    def report(name: String)(f: => Unit) = BenchmarkReport(name, f _)
}

result.txt

Name                    Time(s)
===============================
foo                    0.084000
bar                    0.082000