CODEWITHSUNDEEP
scala
Gulnar Necefova
Gulnar Necefova

Reputation: 25

How to measure execution time of each loop step in Scala?

I wrote a piece of code which measures code execution time in Scala. I want to write such a code that measures and prints execution time of every step of for loop.

import scala.language.postfixOps

def time[T](block: => T): T = {
  val v0 = System.nanoTime()
  val res = block 
  val v1 = System.nanoTime()
  println("Execution time: " + (v1 - v0) + "nanoseconds")
  res

}

var list = time {1 to 10 by 1 toList} // Execution time: 419830nanoseconds

I get the exact result for this code. But I can't write for every step.

Upvotes: 0

Views: 1266

Answers (1)

Mario Galic
Mario Galic

Reputation: 48420

Try 

(1 to 10 by 1).foreach(time(_))

which outputs approximately

Execution time: 8517nanoseconds
Execution time: 603nanoseconds
Execution time: 364nanoseconds
Execution time: 329nanoseconds
Execution time: 339nanoseconds
Execution time: 295nanoseconds
Execution time: 341nanoseconds
Execution time: 312nanoseconds
Execution time: 442nanoseconds
Execution time: 346nanoseconds

Say you had some function applied to each element

def inc(i: Int): Int = i + 1

then you could measure each step like so

(1 to 10 by 1).foreach(v => time(inc(v)))

Upvotes: 2

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