[aspectj-users] AW: Concretize abstract pointcut with subtypes

["Greve, Thomas" <TGreve@xxxxxxxx>]

Hi Charles.

If i got your point right, the reason why you cannot override
pointcuts with subtype arguments is the same as why you cannot
override methods with methods receiving subtype arguments:

class A {}

class B extends A // the subtype
{
  void b() {} // this will trigger the problem
}

abstract class C
{
  abstract void method(A a);
}

class D extends C
{
  void method(B b) // supposed to override C.method(A)
  {
    b.b();
  }
}

class E
{
  A a = new A();
  B b = new B();
  C c = new D();

  void e()
  {
    c.method(b); // allowed, would call b.b()
    c.method(a); // syntactically allowed, but there is no a.b()!
  }
}

Hope, this illustrates the problem well.

- Thomas

> -----Ursprungliche Nachricht-----
>
> Hi, Wes, thanks for the reply. What I'm trying to do is not to
> overload the pointcut, but using a subtype for the type used in
> abstract pointcut, just like in the case of any regular Java
> method. The reason for doing so is that I can write some generic
> advices to deal with supertypes and allow specific extensions.  I
> know it is a syntactic error. I am just wondering if you know why
> this is prohibited. Thanks.
>
> Charles