[604] in java-interest
Re: Operator overloading
daemon@ATHENA.MIT.EDU (Francois BOUSSARD)
Thu Jul 6 13:21:43 1995
Date: Thu, 6 Jul 1995 12:11:44 +0200
From: Francois BOUSSARD <francois@coplanet.fr>
To: java-interest@java.Eng.Sun.COM
> > From Francois Boussard (francois@coplanet.fr)
> >
> > - the Interface concept : good thing in place of virtual
> > functions of C++.
>
> From: johnm@medicus.com (John Mitchell)
>
> What do Java Interfaces have to do with C++ virtual functions? Perhaps
> you are thinking of writing abstract virtual base classes in C++ to
> sorta mimic the Interface concept?
>
Well, i think that such Java constructs :
interface Movable {
public void Move(int dx,int dy);
}
class Cubes implements Movable {
public void Move(int dx, int dy){....}
}
class Sphere implements Movable {
public void Move(int dx, int dy){.....}
}
class Scheduler implement Movable {
private Movable Tab=new Movable[10];
public Register(Movable obj) {Tab[n]=obj;}
public Move(int dx, int dy){for(...) Tab[n].Move(dx,dy)..}
}
class Appli {
static private Cubes c;
static private Sphere s;
static private Scheduler sched;
public static void main(..) {
sched.Register(c);
sched.Register(s);
for(...) sched.Move(x,y);
}
}
Can replace the C++ virtual functions here :
class Movable {
virtual void Move(int dx, int dy)=0;
};
class Cubes : public Movable { public:
virtual void Move(int dx,int dy){..}
};
class Spheres : public Movable { public:
virtual void Move(int dx, int dy){...}
};
class Scheduler implement Movable {
Movable *Tab[10];
public Register(Movable *obj) {Tab[n]=obj;}
public Move(int dx, int dy){for(...) Tab[n]->Move(dx,dy)..}
}
Cubes c;
Sphere s;
Scheduler sched;
void main(..) {
sched.Register(c);
sched.Register(s);
for(...) sched.Move(x,y);
}
>
> > It's provides the concept of virtuality by explicit encapsulation of what is
> > virtual and implemented : realy prety thing .
>
> It's the separation of interface inheritance from implementation
> inheritance. In doing so Java allows for multiple interface inheritance
> but only single implementation inheritance.
>
I agree.
> Take care,
> John
>
Ok, sorry for my mistakes, I spend a long time to read-back my text and
correct my faults, but it's hard to write perfectly (:_:).
> P.S. Just my personal opinions.
>
P.S. Exactly the same !
-
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