Scala example source code file (runtime.scala)

This example Scala source code file (runtime.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, anyref, array, array, foo, m0, m0, m1, n0, n0, n1, printstream, unit, unit

The Scala runtime.scala source code

//############################################################################
// Run Time Bugs & Test Cases
//############################################################################

//############################################################################
// Test 0 - Array creation

object Test0Test {
  def println[A](xs: Array[A]): Unit = {
    var i = 0;
    Console.print("[");
    while (i < xs.length) {
      if (i > 0) Console.print(",");
      Console.print(xs(i));
      i = i + 1;
    }
    Console.print("]");
    Console.println;
  }

  def test(args: Array[String]): Unit = {
    val zs: Array[Boolean] = Array(false, true);
    val bs: Array[Byte   ] = Array(0, 1, 2);
    val ss: Array[Short  ] = Array(3, 4, 5);
    val cs: Array[Char   ] = Array('a', 'b', 'c');
    val is: Array[Int    ] = Array(6, 7, 8);
    val ls: Array[Long   ] = Array(9l, 10l, 11l);
    val fs: Array[Float  ] = Array(12.0f, 13.0f);
    val ds: Array[Double ] = Array(14.0d, 15.0d);
    val os: Array[AnyRef ] = Array("string");
    println(zs);
    println(bs);
    println(ss);
    println(cs);
    println(is);
    println(ls);
    println(fs);
    println(ds);
    println(os);
  }
}

//############################################################################
// Test 1 - Block Qualifiers

package test1.bar {

  object System {
    val out: PrintStream = new PrintStream();
  }

  class PrintStream() {
    def println(): Unit = {
      Console.println;
    }
  }

}

object Test1Test {

  def test(args: Array[String]): Unit = {
    {Console.print(10)}; Console.println;
    // {System.out.print(11); java}.lang.System.out.println();
    // {System.out.print(12); java.lang}.System.out.println();
    // {System.out.print(13); java.lang.System}.out.println();
    {Console.print(14); Console}.println;
    {Console.print(15); (() => Console.println):(() => Unit)} apply ();
    {Console.print(16); Console.println};

    {Console.print(20)}; test1.bar.System.out.println();
    // {System.out.print(21); test1}.bar.System.out.println();
    // {System.out.print(22); test1.bar}.System.out.println();
    {Console.print(23); test1.bar.System}.out.println();
    {Console.print(24); test1.bar.System.out}.println();
    {Console.print(25); test1.bar.System.out.println:(() => Unit)} apply ();
    {Console.print(26); test1.bar.System.out.println()};
  }

}

//############################################################################
// Test 2 - Super Calls with Mixins

package test2 {

  class A {
    def run = Console.println("A");
  }

  trait M0 extends A {
    override def run = { super.run; Console.println("M0"); }
  }

  class M1 extends M0 {
    override def run = { super.run; Console.println("M1"); }
  }

  trait N0 extends A {
    override def run = { super.run; Console.println("N0"); }
  }

  class N1 extends N0 {
    override def run = { super.run; Console.println("N1"); }
  }

  object M0N0 extends M0 with N0;
  object N0M0 extends N0 with M0;
  object M1N0 extends M1 with N0;
  object N1M0 extends N1 with M0;

}

object Test2Test {
  def test(args: Array[String]): Unit = {
    test2.M0N0.run; Console.println;
    test2.N0M0.run; Console.println;
    test2.M1N0.run; Console.println;
    test2.N1M0.run; Console.println;
  }
}

//############################################################################
// Test 3 - Methods eq and ne

object Test3Test {

  class Foo { override def equals(that: Any) = error("abort"); }

  def check(expected: Boolean, actual1: Boolean, actual2: Boolean): Unit =
    Console.println(
      if ((actual1 == expected) && (actual2 == !expected)) "Ok" else "KO: "
        + "expected: " + expected + " - " + (!expected) + ", "
        + "found: " + actual1 + " - " + actual1);

  def test(args: Array[String]): Unit = {
    val foo1: AnyRef = null;
    val foo2: AnyRef = new Foo();
    val foo3: AnyRef = new Foo();

    check(true , null eq null, null ne null);
    check(true , null eq foo1, null ne foo1);
    check(false, null eq foo2, null ne foo2);
    check(false, null eq foo3, null ne foo3);

    check(true , foo1 eq null, foo1 ne null);
    check(true , foo1 eq foo1, foo1 ne foo1);
    check(false, foo1 eq foo2, foo1 ne foo2);
    check(false, foo1 eq foo3, foo1 ne foo3);

    check(false, foo2 eq null, foo2 ne null);
    check(false, foo2 eq foo1, foo2 ne foo1);
    check(true , foo2 eq foo2, foo2 ne foo2);
    check(false, foo2 eq foo3, foo2 ne foo3);

    check(false, foo3 eq null, foo3 ne null);
    check(false, foo3 eq foo1, foo3 ne foo1);
    check(false, foo3 eq foo2, foo3 ne foo2);
    check(true , foo3 eq foo3, foo3 ne foo3);
  }

}

//############################################################################
// Main

object Test  {
  var errors: Int = 0;
  def test(name: String, test: => Unit): Unit = {
    Console.println("<<< " + name);
    try {
      test;
    } catch {
      case exception => {
        //val name: String = Thread.currentThread().getName();
        Console.print("Exception in thread \"" + name + "\" " + exception);
        Console.println;
        errors = errors + 1;
      }
    }
    Console.println(">>> " + name);
    Console.println;
  }

  def main(args: Array[String]): Unit = {

    test("Test0"  , Test0Test.test(args));
    test("Test1"  , Test1Test.test(args));
    test("Test2"  , Test2Test.test(args));
    test("Test3"  , Test3Test.test(args));

    if (errors > 0) {
      Console.println;
      Console.println(errors + " error" + (if (errors > 1) "s" else ""));
    }
  }
}

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