DIP 50 - AST macros

[Dmitry Olshansky]

12-Nov-2013 21:03, Dicebot пишет:
> On Tuesday, 12 November 2013 at 16:54:19 UTC, Andrei Alexandrescu wrote:
>> I don't see how AST reflection is needed for generating correct D code
>> from an SQL expression. Dmitry did exactly that with ctRegex. Please
>> illuminate.
>
> Other way around. Generating arbitrary output (including but not limited
> to SQL expressions) from D code. As I have already mentioned, it is the
> very same thing we do now with __traits and UDA's but not limited to
> only declarations.

Actually I couldn't shake off the feeling that macros are just CTFE 
functions on Ast objects. How objects are created and converted back to 
source code is a separate question.

If we just had:

//this would invoke compiler's parser at CTFE
auto ast = "x = y;".astof

and have it work at CTFE to return sensible AST (a big if btw).

And then (after some manipulations):
ast.toString() //get back a string of D code

It may help code generation of D --> DSL.

Alternatively one can implement D parser that works at CTFE and watch it 
crawl :)

-- 
Dmitry Olshansky