Executing pure D at compile-time

[janderson]

kris wrote:
> Following on from the "Regex Redux thread, it seems to me there's an 
> easy way to execute pure D at compile-time. A few elements are needed:
> 
> 1) the ability to describe a compile-time function call
> 2) the facility to pass arguments to it, and recieve a return value
> 3) a means of identifiying the D code to execute
> 4) a manner in which the pure D is executed
> 5) a mechanism for ensuring the executed code is docile
>  
> Thoughts?
> 
> - Kris
> 

I like this approach (essentially its what I was suggesting in a 
previous thread).  This would be an very powerful addition to D.  How 
would it determine 5 when you can create objects.  I'm guessing each 
method in the class would need to be labeled extension. All the compiler 
would do is validate that "extension" is true (like a constant), 
otherwise not compile.

As for naming I prefer the term "compiletime".


My last thought on the matter which I haven't posted was a slightly 
different one (take it or leave it).   Why not extend the template 
syntax so that it looks like every day D code.

First I would get rid of the static if, its inside a template, that 
should be able to be figured out.  Next I would add case statements and 
for loops.  Also compile time variables (int float, arrays, associative 
arrays).  Because these are in a template they would be detected as 
compile time.  However that wouldn't be nearly as powerful because you 
have no way to reuse code and you can't create new objects.