DIP69: problem with scope grammar - need a new keyword

[deadalnix via Digitalmars-d]

On Monday, 8 December 2014 at 10:37:29 UTC, Walter Bright wrote:
> On 12/8/2014 1:52 AM, deadalnix wrote:
>> On Monday, 8 December 2014 at 09:46:03 UTC, Walter Bright 
>> wrote:
>>> I thought I could make this work, but it's a problem. There 
>>> are two meanings
>>> for scope when attached to a function:
>>>
>>>    T func() scope;   // the 'this' pointer is 'scope'
>>>    scope T func();   // the function returns a 'scope' T
>>>
>>> I have some ideas, but don't particularly like any of them. 
>>> But I don't want
>>> to bias things, so what ideas do you guys have?
>>
>> I'm arguing for ages that qualifier before the return type 
>> qualify the return
>> type, and the one after the implicit argument. I stand by this.
>
> Another problem with that is:
>
>   void func(scope T delegate() dg);

Nop. I actually made a proposal that was more complete and
handled such case.

qualifier on the left qualify the return type. qualifier in
between return type and function/delegate qualify both the symbol
and the context (it implicit parameter) and qualifier on the
right qualify only the context.