Recursive factorial in scala with performance metrics

metrics_factorial.scala

import org.scalameter._

object FactorialRunner {

  def fact(v: BigInt): BigInt = {
    def recFact(v: BigInt, acc: BigInt): BigInt =
      if (v == 1) acc else recFact(v - 1, acc * v)

    recFact(v, 1)
  }

  val standardConfig = config(
    Key.exec.minWarmupRuns -> 20,
    Key.exec.maxWarmupRuns -> 40,
    Key.exec.benchRuns -> 25,
    Key.verbose -> true
  ) withWarmer new Warmer.Default

  def main(args: Array[String]): Unit = {
    val meanTime = standardConfig measure {
      fact(20000)
    }

    println(s"factorial of 20000 mean time: $meanTime ms")
  }
}

Requires scalameter library in build.sbt:

name := "Factorial with metrics"

scalaVersion := "2.11.8"

libraryDependencies ++= Seq(
  "com.storm-enroute" %% "scalameter-core" % "0.6",
  "com.storm-enroute" %% "scalameter" % "0.6" % "test"
)

Execute via sbt console: run-main FactorialRunner