Re: Source code output

[John Colvin]

On Wednesday, 17 July 2013 at 05:29:26 UTC, H. S. Teoh wrote:
On Wed, Jul 17, 2013 at 05:27:34AM +0200, JS wrote:
With heavy ctfe code generation usage is it possible to have 
the d
compiler output the source code after all mixin templates have 
been
"used"? This way it is easier to visually check for errors in 
the
generated code.
I imagine one could use pragma in a "special way" to do this 
but I
was hoping for something more direct.

Yeah I've been looking for this too. Once you have templates 
and mixins
nested deeply enough, it can be near impossible to figure out 
just
exactly *what* is being compiled at the end of it all.

Though I suppose the common approach is to generate a string
representing the code, and then using mixin(str) to compile it; 
this
lets you use pragma(msg) to output str and thereby see what 
exactly is
being compiled. But this may not be possible in some cases.


T

I would love to have .codeof that can be applied to as many 
things as possible.

Or __traits(code, ...)

Or __traits(code, expansion_depth, ...)

So as to be able to drill down in to the code of something to the 
necessary level but no further.


Btw, this isn't only useful for printing out, it would be a 
powerful compile-time tool in general:

E.g. given a function
void foo(int a, int b)
{ body }

it would then be possible to do:

void fooCompileTimeCurried(int a)(int b)
{
    mixin(stripSig(__traits(code, 1, foo)));
}

to get an optimised version of foo for a == some_ct_value