DIP 50 - AST macros

[Ellery Newcomer]

On 11/11/2013 12:06 PM, deadalnix wrote:
> 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.

so if I have to splice my ast N times, then I have to generate M $'s 
depending on when I want it to expand?