/*
  This example shows how you can create anonymous classes that implement
  an interface.
  The example adds functions to a mythical calculator that has
  a method for adding functions to the calculator.
*/

class AnonymousExample {
    public static void main(String[] args) {
        MyCalc calc = new MyCalc();
        
        calc.add(
            new UnaryFunction() {
                public double eval(double x) {
                    return Math.sin(x);
                }
                public String toString() {
                    return "sin(x)";
                }
            }
        );
        calc.add(
            new BinaryFunction() {
                public double eval(double x, double y) {
                   if (x < y) return x;
                   else return y;
                }
                public String toString() {
                    return "min(x, y)";
                }
            }
        );
    }
}

/*
  Mythical calculator. Just enough to get the example above to compile.
 */
class MyCalc {
    void add(UnaryFunction f) {}
    void add(BinaryFunction f) {}
}