Chapter: Generics

Create and test a SixTuple generic.

In Java:

package chapter.generics;

class SixTuple<A, B, C, D, E, F> {
    public final A a;
    public final B b;
    public final C c;
    public final D d;
    public final E e;
    public final F f;

    public SixTuple(A a, B b, C c, D d, E e, F f) {
        this.a = a;
        this.b = b;
        this.c = c;
        this.d = d;
        this.e = e;
        this.f = f;
    }
}

public class Exercise3 {

    static SixTuple<Integer, String, Double, Boolean, String, Integer> foo() {
        return new SixTuple<Integer, String, Double, Boolean, String, Integer>(
                5, "hi", 33.3, true, "bye", 100);
    }

    public static void main(String[] args) {
        SixTuple<Integer, String, Double, Boolean, String, Integer> x = foo();
        System.out.println(x.b);
        System.out.println(x.a);
        System.out.println(x.e);

    }

}

Lisp can return values in many natural and easy ways, including lists and the values function. Since a lisp programmer would probably avoid creating a special tuple class just to return multiple values, here is an alternative and simple way to accomplish the feat:

(defun foo ()
  (values 5 "hi" 33.3 t "bye" 100))

(multiple-value-bind (a b c d e f) (foo)
  (print b)
  (print a)
  (print e))