feature request: __ARGS__ for logging (cf __FILE__, __LINE__, __FUNC___)

[Timon Gehr]

On 02/05/2013 08:28 AM, Jacob Carlborg wrote:
> On 2013-02-05 01:15, Timon Gehr wrote:
>
>> IMO macros should be fully hygienic by default, with opt-out options.
>
> That's the opposite of how the macros in Scala works.
>

As far as my understanding goes, quasi-quoting is hygienic, and manual 
AST building provides both options.

> It's quite easy to say if it should be hygienic or not. The hard part is
> to figure out the details and how to break hygienicy, when there's need
> for it.
>

We could provide all nested scopes in an array as part of the context.

macro foo(Context context){
     return<[
         context.scopes[0].x++;
         context.scopes[1].x++;
     ]>;
}
int x = 2;
void main(){
     int x=0;
     foo();
     assert(x==1 && .x==3);
}

If manual AST building is supported, it could additionally do something 
along the following lines:


module macros;
int x=0;
macro foo(Context context){
     return SequenceExp(
         AssignExp(Symbol!x(), Constant(1)),
         AssignExp(Identifier("x"), Constant(2)),
     );
}

// ---
module m;
import macros;
int x=0;

void main(){
     foo();
     assert(macros.x==1 && x==2);
}