Benchmark.scala

import scala.testing.Benchmark
import java.util.Timer



class For(MAX_LOOP:Int) {
    var sum:Int = 0
    def run() = {
        println("iterate " + MAX_LOOP + " times...")
        val start:Long = System.currentTimeMillis()
        for (val n <- 1 to MAX_LOOP) sum += n
        val end:Long = System.currentTimeMillis()
        println("For: " + (end - start) + " ms")
    }

    println(MAX_LOOP + " times of loop of For")
    assert(MAX_LOOP > 0)
}
class ForEach(MAX_LOOP:Int) {
    var sum:Int = 0
    def run() = {
        println("iterate " + MAX_LOOP + " times...")
        val start:Long = System.currentTimeMillis()
        (1 to MAX_LOOP).foreach((n) => sum += n)
        val end:Long = System.currentTimeMillis()
        println("ForEach: " + (end - start) + " ms")
    }

    println(MAX_LOOP + " times of loop of ForEach")
    assert(MAX_LOOP > 0)
}
class ForPrimitive(MAX_LOOP:Int) {
    var sum:Int = 0
    def run() = {
        println("iterate " + MAX_LOOP + " times...")
        val start:Long = System.currentTimeMillis()
        var i:Int = 1
        while (i <= MAX_LOOP) {
            sum += i
            i += 1
        }
        val end:Long = System.currentTimeMillis()
        println("ForPrimitive: " + (end - start) + " ms")
    }

    println(MAX_LOOP + " times of loop of ForPrimitive")
    assert(MAX_LOOP > 0)
}

object Main extends Application {

    val MAX_LOOP = 100 * 1000 * 1000

    val eachTest:Array[Benchmark] = Array[Benchmark](
        new For(MAX_LOOP) with Benchmark,
        new ForEach(MAX_LOOP) with Benchmark,
        new ForPrimitive(MAX_LOOP) with Benchmark
    )
    for (val bench:Benchmark <- eachTest)
        bench.run
    println
}


// vim:ft=scala: