static this sucks, we should deprecate it

[Steven Schveighoffer]

On Thu, 28 May 2009 17:37:57 -0400, Ary Borenszweig <ary at esperanto.org.ar>  
wrote:

> Frank Benoit escribió:
>> Unknown W. Brackets schrieb:
>>> Probably a silly idea, but what about (or similar):
>>>
>>> static this: mod.name, mod.name2, mod.name3
>>> {
>>> }
>>>
>>> For a dependency list.  I may be wrong, but afaik the main problems  
>>> stem
>>> from either wrong order or co-dependence (which needs to be solved by
>>> the programmer.)
>>>
>>> At least with this, you could ask the compiler for an order,
>>> potentially.  If the other modules had no static this, it could ignore
>>> it, allowing future proofing.
>>>
>>> But, maybe that's an ugly hack.
>>>
>>> -[Unknown]
>>>
>>  In Java the
>> static { /* static ctor code */ }
>> does not have the circular dependency problem. why is that?
>
> Consider this:
>
> class A {
>
> 	public static int x;
>
> 	static {
> 		x = B.x + 10;
> 	}
>
> 	public static void main(String[] args) {
> 		System.out.println("A.x = " + A.x);
> 		System.out.println("B.x = " + B.y);
> 	}
>
> }
>
> class B {
>
> 	public static int y;
>
> 	static {
> 		y = A.x + 10;
> 	}
>
> 	public static void main(String[] args) {
> 		System.out.println("A.x = " + A.x);
> 		System.out.println("B.x = " + B.y);
> 	}
>
> }
>
> If you run A, you'll get:
>
> A.x = 20
> B.x = 10
>
> If you run B, you'll get:
>
> A.x = 10
> B.x = 20
>
> That's because the static { } is run when the class is first loaded.
>
> So in a sense there is the problem is circular dependency: depending on  
> the order of class loading you get different results.
>
> Is this the problem being discussed, how to define the order of static  
> this?


Yes.

So Java basically allows the circular dependency because it assumes you  
know what you are doing :)  That could be even worse than the D solution!

However, I think this could be solved in Java more readily than it could  
be in D...

-Steve