RosettaCodeData/Task/Delegates/Elena/delegates-1.elena

import extensions;
import system'routines;

interface IOperable
{
    abstract operate();
}

class Operable : IOperable
{
    constructor() {}

    operate()
        = "delegate implementation";
}

class Delegator
{
    object theDelegate;

    set Delegate(object)
    {
        theDelegate := object
    }

    internal operate(operable)
        = "default implementation";

    internal operate(IOperable operable)
        = operable.operate();

    operate()
        <= operate(theDelegate);
}

public Program()
{
    var delegator := new Delegator();

    new object[]{nil, new Object(), new Operable()}.forEach::(o)
    {
       delegator.Delegate := o;

       Console.printLine(delegator.operate())
    }
}