template debuging

[JS]

On Thursday, 18 July 2013 at 11:46:39 UTC, John Colvin wrote:
> On Thursday, 18 July 2013 at 11:16:26 UTC, JS wrote:
>> Anyone successful at debugging templates and ctfe?
>>
>> Also, I am using pragma a lot because it seems to be the most 
>> direct way to get ctfe state information.
>>
>> I would like to be able to toggle when to show pragma so I can 
>> conditionally enable it during compilation.
>>
>> e.g., suppose I have a template T that I has pragma debug 
>> messaging and I want to enable it only for a call to T:
>>
>> ___DEBUG___ = true;
>> T!()
>> ___DEBUG___ = false;
>>
>>
>> (Not sure if this will produce the correct result depending on 
>> how the compiler analyzes the code)
>>
>> Right now I have to use an immutable bool for debug which is a 
>> global toggle... I don't see any thing around it because I 
>> can't change an immutable at compile time(or can I?)... which, 
>> technically should be valid because an immutable is a 
>> declaration about the state of a variable at run time, so I 
>> should be able to change it at compile time without changing 
>> that fact.
>>
>> e.g.,
>>
>> immutable bool x = true;
>>
>> x $= false; // $= means static assignment, a compile time 
>> assignment.. not sure if x should be true or false for the 
>> whole program at run time(probably true, site of definition).
>>
>> Or
>>
>> ctfe bool x = true; defines a ctfe variable at compile time. x 
>> doesn't exist a run time.
>
> If I understand you correctly, this might be useful to you:
>
> void Msg(msgs ...)()
> {
>     debug
>     {
>         foreach(m; msgs)
>         {
>             pragma(msg, m);
>         }
>     }
> }
>
> which is a no-op if you don't pass -debug on the command line.
>
> or alternatively you could wrap your pragma(msg, ...) statments 
> in version(TemplateNameDebug), meaning you can turn them on 
> individually with -version switches

? It is still global.

T!("x");
T!("y"); // I want to see the pragma outputs of only this template
T!("z");

I also want "library" level debugging instead of whole program 
debugging. (although I suppose one could compile each module 
separately each with it's own -debug).

For example

immutable bool _MyLibrary_DEBUG_ = true;

is a library level debug toggle, not whole program... it won't 
effect other libraries.