Proposal keyword 'outer' (mixins)

[Don Clugston]

Tom S wrote:
> Bruno Medeiros wrote:
>> Tom S wrote:
>>> Bruno Medeiros wrote:
>>>> Seems an ok proposal for outer classes.
>>>> But as for mixins that doesn't make sense, the scope they access is 
>>>> already the scope of the instantiation.
>>>
>>> That's the point. The rules for mixins must change as they are 
>>> inconsistent and error prone at the moment. IMO they should only be 
>>> granted access to the outer scope thru the 'outer' keyword and by 
>>> default only see the scope of their declaration.
>>>
>>>
>>
>> Ok, but then that's a whole other issue altogether.
> 
> Uhmm... how ? You said it didn't make sense for mixins and I claim that 
> it does and that they will benefit from the 'outer' keyword. Actually, 
> it's more important for them than for inner classes, as the current 
> rules for mixins are way borked IMO...

It's really important that mixins be able to access outer variables 
without knowing how deep they are.  I think this is quite different from 
the situation for inner classes.

ie, in a mixin, if you had to write

outer.outer.outer.x

mixins would lose most of their power.

I'd be in favour of syntax which said:
(a) this template is intended for use as a mixin; and
(b) I'm importing the next symbol from _somewhere_ outside the mixin.

> Seems to me like D needs a major rehash of its visibility rules...

I don't think anyone would disagree with that. Seems to have become the 
#1 D issue right now.