Scala example source code file (enums.scala)

This example Scala source code file (enums.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

direction, east, enumeration, int, int, north, north, south, south, test2, value, value, waiting, west

The Scala enums.scala source code

//############################################################################
// Enumerations
//############################################################################

object Test1 {

  object WeekDays extends Enumeration  {
    val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
  }

  def isWorkingDay(d: WeekDays.Value) =
    ! (d == WeekDays.Sat || d == WeekDays.Sun);

  def run: Int = {
    val it = WeekDays.values filter (isWorkingDay);
    it.toList.length
  }
}

object Test2 {

  object ThreadState extends Enumeration {
    val New          = Value("NEW");
    val Runnable     = Value("RUNNABLE");
    val Blocked      = Value("BLOCKED");
    val Waiting      = Value("WAITING");
    val TimedWaiting = Value("TIMED_WAITING");
    val Terminated   = Value("TERMINATED");
  }

  def run: Int = {
    val it = for (s <- ThreadState.values; if s.id != 0) yield s;
    it.toList.length
  }
}

object Test3 {

  object Direction extends Enumeration("North", "South", "East", "West") {
    val North, South, East, West = Value;
  }

  def run: Int = {
    val it = for (d <- Direction.values; if d.toString() startsWith "N") yield d;
    it.toList.length
  }
}

object Test4 {

  object Direction extends Enumeration("North", "South", "East", "West") {
    val North, South, East, West = Value;
  }

  def run: Int = {
    val dir = Direction.withName("North")
    assert(dir.toString == "North")
    try {
      Direction.withName("Nord")
      assert(false)
    } catch {
      case e: Exception => /* do nothing */
    }
    0
  }
}

//############################################################################
// Test code

object Test {

  def check_success(name: String, closure: => Int, expected: Int): Unit = {
    Console.print("test " + name);
    try {
      val actual: Int = closure;
      if (actual == expected) {
        Console.print(" was successful");
      } else {
        Console.print(" failed: expected "+ expected +", found "+ actual);
      }
    } catch {
      case exception: Throwable => {
        Console.print(" raised exception " + exception);
        exception.printStackTrace();
      }
    }
    Console.println;
  }

  def main(args: Array[String]): Unit = {
    check_success("Test1", Test1.run, 5);
    check_success("Test2", Test2.run, 5);
    check_success("Test3", Test3.run, 1);
    check_success("Test4", Test4.run, 0);
    Console.println;
  }
}

//############################################################################