import scala.tools.partest._ // Attempting to verify slice isn't 100,000x slower // with views than non-views. class Runner(num: Int, reps: Int) extends TestUtil { var dummy = 0 val range = Array.range(0, num) def iteratorSlice = { def it = range.iterator.slice(num - 2, num) for (i <- 1 to reps) it foreach (dummy = _) } def viewSlice = { val view = range.view.slice(num - 2, num) for (i <- 1 to reps) view foreach (dummy = _) } def straightSlice = { val xs = range.slice(num - 2, num) for (i <- 1 to reps) xs foreach (dummy = _) } def run(multiple: Double) = { verifySpeed(straightSlice, iteratorSlice, multiple) verifySpeed(straightSlice, viewSlice, multiple) } } object Test { def main(args: Array[String]): Unit = { // warmup { val r = new Runner(1000000, 10) ; r.straightSlice ; r.iteratorSlice ; r.viewSlice } new Runner(10000000, 10) run 500 new Runner(10000000, 50) run 300 } }