Scala example source code file (overloads.scala)

This example Scala source code file (overloads.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, char, char, int, int, m2, ops, ops, ordered, ordered, string, test, unit

The Scala overloads.scala source code

//############################################################################
// Overloads
//############################################################################

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

object Ops {
    def - = 0;
    def -(c: Char) = c;
    def -(i: Int) = i;

    def -- = 0;
    def --(c: Char) = c;
    def --(i: Int) = i;
}

object Funcs {
    def foo = 0;
//  def foo() = 1;
    def foo(c: Char) = 2;
    def foo(i: Int) = 3;
}

object M1 {
    def f[A](x: A) = 11;
    def f[A <: Ordered[A]](x: Ordered[A]) = 12;
}

object M2 {
    def f[A <: Ordered[A]](x: Ordered[A]) = 21;
    def f[A](x: A) = 22;
}

object overloads {

    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 - = 0;
    def -(c: Char) = c;
    def -(i: Int) = i;

    def -- = 0;
    def --(c: Char) = c;
    def --(i: Int) = i;

    def test: Unit = {
        check("-('a')", -('a'), -97);
        check("-(97)", -(97), -97);

        check("Ops.-('a')", Ops.-('a'), 'a');
        check("Ops.-(97)", Ops.-(97), 97);

        check("--", --, 0);
        check("--('a')", --('a'), 'a');
        check("--(97)", --(97), 97);

        check("Ops.--", Ops.--, 0);
        check("Ops.--('a')", Ops.--('a'), 'a');
        check("Ops.--(97)", Ops.--(97), 97);

        check("Funcs.foo", Funcs.foo, 0);
//      check("Funcs.foo()", Funcs.foo(), 1);
        check("Funcs.foo('a')", Funcs.foo('a'), 2);
        check("Funcs.foo(97)", Funcs.foo(97), 3);

        val x = 3;
        check("M1.f(" + x +")", M1.f(x), 11);
        check("M2.f(" + x +")", M2.f(x), 22);
//       val y = new scala.collection.mutable.Stack[Int];
//      check("M1.f(" + y +")", M1.f(y), 12);
//      check("M2.f(" + y +")", M2.f(y), 21);
    }

}

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

object Test {

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

}

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