Re: [Vala] Delegation in vala

[Matt Emson <memsom interalpha co uk>]

Кутейников Дмитрий wrote:

A thought on syntax:
> *================================*
>
> * class A : Object {
>    public void foo() {
>        stdout.printf("Object A doing the job.");
>      }
>  };*
>
> *class B : Object {
> *
>
> *   public A a;
>    public void foo() {
>         a.foo();
>      }
>  };
>   


Delphi does something like this, and uses the keyword "implements". 
Delphi also uses Interfaces as the bridge. So Vala would do something 
like (forgive my syntax errors as I've not got round to doing much Vala 
recently and have a head full of C# today):

interface IA
{
 public abstract void foo();
}

class A : Object, IA {
  public void foo() {
      stdout.printf("Object A doing the job.");
    }
};


class B : Object, IA {

protected A a implements IA;

};

or maybe:

class B : Object, IA {
 [Implements(IA)] protected A a;

};


> **================================*
> If there are lots of objects to delegate, there will be LOTS of
> unnecessary code with proxy methods.
> And when I add/remove method from A, I need to change all B-like
> classes manually :(
>   

This is implementing a half house multiple inheritance really, isn't it?

M