Dynamic binding

[Katarina Olsson <katolsster@gmail.com>]

Hello,
I have a question about dispatching in Ada. As we know, methods in
java are always called on their objects. Let say that we have a class
Parent with methods a() and b(), where a calls b like this:

class Parent{

public void a() {
System.out.println("parent a");
b();
}

public void b(){
System.out.println("parent b");
}
}

Consider now the class Child extends Parent. It has overridden the b()
method like this:

class Child extends Parent{

@Override
public void b(){
System.out.println("child b");
}

}

When creating a Child object and calling the a() method,

Child c = new Child();
c.a();

the output will be the following on stdout:

>>parent a
>>child b

I have now attempted to reproduce the corresponding case in Ada. If I
create a tagged record Object in package Parent, and then the
corresponding procedures (or functions):

procedure A (This : access all Object);
procedure B (This : access all Object);

and then in package Child, I create a new Parent.Object:

type Object is new Parent.Object with null record

...and override the B method:

overrides
procedure B (This : access all Object)

This should correspond to the previous java case, shouldn't it? In any
case it seems to me that calling the A procedure on the Child Object,
would render the output

>>parent a
>>parent b -- (instead of child b)

Do I need to try again or have I understood it correctly? And if I
have, how would I best reproduce the java behaviour?