The future of UDAs.

[Gor Gyolchanyan]

I can't recall the exact use case which drove me to this topic at the
moment. I'll definitely post it as soon as I remember. D's CTFE, mixins and
templates almost make up a full language for compile-time. This allows
generating the source code from within source code. The problem is that
it's impossible to perform compile-time actions on a combination of modules
in different compiler runs. different directly unrelated modules could
contribute to the code generation process if mutable compile-time variables
were available.


On Tue, Nov 27, 2012 at 8:59 PM, David Nadlinger <see at klickverbot.at> wrote:

> On Tuesday, 27 November 2012 at 15:49:45 UTC, Gor Gyolchanyan wrote:
>
>> Can you implement this use case?
>> Have classes mix in something,, which will register them in a single
>> place,
>> which can later suppl the registered classes as a type tuple.
>>
>
> This is fundamentally impossible in the D module system if the "single
> place" S does not import the modules where the types are defined. Even if
> you could append strings to a "compile-time global" in S, this still
> wouldn't help you in any way because if you tried to mix in the string in
> S, you'd get nothing but a slew of undefined symbol errors.
>
> Maybe you can describe your use case a bit? I'm optimistic that there is a
> solution which is not radically incompatible with the design of D.
>
> David
>



-- 
Bye,
Gor Gyolchanyan.
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