A.scala

// Emulating loop breaks with loop condition 
object A {
  def main(args: Array[String]) = {
    val start = System.currentTimeMillis

    val until = Int.MaxValue
    var i = 0

    var c = 0

    while (i < until) {
      var j = 0
      var cont = true
      while (cont) {
        if (j >= i) {
          c += 1
          cont = false
        } else {
          j += 1
        }
      }

      i += 1
    }

    println(c)
    println(System.currentTimeMillis - start)
  }
}

A.sout

2147483647
4204

B.scala

import scala.util.boundary
import boundary.{Label, break}

// Breaking the loop with `boundary/break`
object B {
  def main(args: Array[String]) = {
    val start = System.currentTimeMillis

    val until = Int.MaxValue
    var i = 0

    var c = 0

    while (i < until) {
      boundary {
        var j = 0
        while (true) {
          if (j >= i) {
            c += 1
            break()
          }
          j += 1
        }
      }
      i += 1
    }

    println(c)
    println(System.currentTimeMillis - start)
  }
}

B.sout

2147483647
127

C.scala

import scala.util.boundary
import boundary.{Label, break}

// Non-local `boundary/break`
object C {
  def main(args: Array[String]) = {
    val start = System.currentTimeMillis

    val until = Int.MaxValue
    var i = 0

    var c = 0

    while (i < until) {
      boundary {
        for (j <- Iterator.from(0)) {
          if (j >= i) {
            c += 1
            break()
          }
        }
      }
      i += 1
    }

    println(c)
    println(System.currentTimeMillis - start)
  }
}

C.sout

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