DIP 50 - AST macros

[deadalnix]

On Monday, 11 November 2013 at 19:23:21 UTC, Ellery Newcomer 
wrote:
> On 11/10/2013 01:20 PM, Jacob Carlborg wrote:
>> I've been thinking quite long of how AST macros could look 
>> like in D.
>> I've been posting my vision of AST macros here in the 
>> newsgroup a couple
>> of times already. I've now been asked to create a DIP out of 
>> it, so here
>> it is:
>>
>> http://wiki.dlang.org/DIP50
>>
>
> For macros that generate macros, I think you need a way to 
> escape the splicing and maybe define how splicing works in an 
> inner quasi quote.
>
> I guess you want <[ <[ $exp ]> ]> to turn into the ast <[ 1 ]>
>
> Then if you wanted ast <[ <[ $exp ]> ]> with the splice 
> associated with the inner quasi quote, you'd have to do 
> something like
>
> <[ <[ <[ \\\$exp ]> ]> ]>
>
> maybe a way to associate a splice with a quasi quote?
>
> <a[ <b[ <c[ $(a, exp) + $(b, exp) + $(c, exp)  ]> ]> ]>
>
> a's exp is A
> b's exp is B
> c's exp is C
>
> then splice the quasi quote N times:
>
> 1: ast <b[ <c[ A + $(b, exp) + $(c, exp) ]> ]>
> 2: ast <c[ A + B + $(c, exp) ]>
> 3: ast A + B + C
>
> just dinking around here

$ refers to the enclosing scope. so $$foo should refers to $foo 
in the enclosing scope. No need for special rule or label.