DIP 50 - AST macros

[deadalnix]

On Monday, 18 November 2013 at 09:25:22 UTC, Walter Bright wrote:
> On 11/17/2013 9:10 PM, deadalnix wrote:
>> On Monday, 18 November 2013 at 05:05:02 UTC, Walter Bright 
>> wrote:
>>> On 11/17/2013 7:14 PM, deadalnix wrote:
>>>> As I understand it, Timon choosed that syntax simply to 
>>>> demonstrate the
>>>> limitation of your proposal using a similar syntax. Not to 
>>>> propose a syntax.
>>>
>>> Ok, then I'm not seeing what AST macros do that lazy 
>>> parameters / template
>>> overloading / mixin templates do not?
>>
>> 2 things. First, they can act on statement or declaration. 
>> Simply not with the
>> proposed syntax.
>
> If they can insert a statement or a declaration uplevel, then 
> they are doing what I suggested with the return statement.
>
>> Second they can reflect what is passed as argument and act
>> accordingly, when the lazy expression solution cannot.
>
> Expression templates can.


*Expression* templates.