Scala example source code file (exceptions.scala)

This example Scala source code file (exceptions.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

a, any, boolean, empty, empty, int, intmap, intmap, ko, ko, string, test, unit, unit

The Scala exceptions.scala source code

//############################################################################
// Exceptions
//############################################################################

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

abstract class IntMap[A] {
    def lookup(key: Int): A = this match {
        case Empty() => error("KO")
        case _ => error("ok")
    }
}

case class Empty[A]() extends IntMap[A];

object exceptions {

    def check(what: String, actual: Any, expected: Any): Unit = {
        val success: Boolean = actual == expected;
        Console.print(if (success) "ok" else "KO");
        var value: String = if (actual == null) "null" else actual.toString();
        if (value == "\u0000") value = "\\u0000";
        Console.print(": " + what + " = " + value);
        if (!success) Console.print(" != " + expected);
        Console.println;
        Console.flush;
    }

    def test: Unit = {
        val key = 2000;
        val map: IntMap[String] = new Empty[String];
        val value = try {
            map.lookup(key)
        } catch {
            case e => e.getMessage()
        }
        check("lookup(" + key + ")", value, "KO");
    }

}

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

object Test {

  def main(args: Array[String]): Unit = {
    exceptions.test;
  }

}

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