Continue

杨博 (Yang Bo)

Each for creating collection comprehensions.

This Continue keyword is usually used with Each, to skip an element in the loop.

Each and Continue can be used to calculate composite numbers and prime numbers.

        import com.thoughtworks.dsl.bangnotation._
        def compositeNumbersBelow(maxNumber: Int) = *[collection.immutable.HashSet] {
          val factor = !Each(2 until math.ceil(math.sqrt(maxNumber)).toInt)
          !Each(2 * factor until maxNumber by factor)
        }
        compositeNumbersBelow(13) should be(Set(4, 6, 8, 9, 10, 12))
        def primeNumbersBelow(maxNumber: Int) = *[Seq] {
          val compositeNumbers = compositeNumbersBelow(maxNumber)
          val i = !Each(2 until maxNumber)
          if (compositeNumbers(i)) !Continue
          i
        }
        primeNumbersBelow(13) should be(Array(2, 3, 5, 7, 11))