Problem Statement

An object is polymorphic when its specific type may vary. The types a specific value may take, is called class. It is trivial to copy an object if its type is known: Here x is not polymorphic, so y is declared of same type (int) as x. But if the specific type of x were unknown, then y could not be declared of any specific type. The task: let a polymorphic object contain an instance of some specific type S derived from a type T. The type T is known. The type S is possibly unknown until run time. The objective is to create an exact copy of such polymorphic object (not to create a reference, nor a pointer to). Let further the type T have a method overridden by S. This method is to be called on the copy to demonstrate that the specific type of the copy is indeed S.

Let's start with the solution:

define: #T &parents: {Cloneable}.

define: #S &parents: {Cloneable}.

define: #obj1 -> T clone.
define: #obj2 -> S clone.

obj1 printName.
obj2 printName.