Scala example source code file (hashCodeBoxesRunTime.scala)

This example Scala source code file (hashCodeBoxesRunTime.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

array, array, character, int, list, list, long, test, test, unit, unit

The Scala hashCodeBoxesRunTime.scala source code

// This only tests direct access to the methods in BoxesRunTime,
// not the whole scheme.
object Test
{
  import java.{ lang => jl }
  import scala.runtime.BoxesRunTime.{ hashFromNumber, hashFromObject }
  
  def allSame[T](xs: List[T]) = assert(xs.distinct.size == 1, "failed: " + xs)
  
  def mkNumbers(x: Int): List[Number] =
    List(x.toByte, x.toShort, x, x.toLong, x.toFloat, x.toDouble)
  
  def testLDF(x: Long) = allSame(List[Number](x, x.toDouble, x.toFloat) map hashFromNumber)
   
  def main(args: Array[String]): Unit = {
    List(Byte.MinValue, -1, 0, 1, Byte.MaxValue) foreach { n => 
      val hashes = mkNumbers(n) map hashFromNumber
      allSame(hashes)
      if (n >= 0) {
        val charCode = hashFromObject(n.toChar: Character)
        assert(charCode == hashes.head)
      }
    }
    
    testLDF(Short.MaxValue.toLong)
    testLDF(Short.MinValue.toLong)
  }
}