Chances of D getting proper runtime reflection?

[Mehrdad]

On 8/21/2011 3:55 AM, Jacob Carlborg wrote:
> What are the chances of D getting proper runtime reflection? Something 
> like this:
>
> class Foo
> {
>     private int a;
>
>     private void bar (int i)
>     {
>         a = i;
>     }
> }
>
> auto foo = new Foo;
> Object o = foo;
> o.setInstanceVariable("a", 3);
> assert(foo.a == 3);
>
> This would be useful as well:
>
> o.send("bar", 5);
> assert(foo.a == 5);
> assert(foo.a == o.getInstanceVariable("a"));
>
> Currently I have most use of the first example. These example should 
> work regardless if the fields/methods are private, protected or public.
>
> As far as I know this wouldn't require any changes to the language, 
> only the compiler and runtime would need to be modified. To me, it 
> doesn't look that complicated to implement, the runtime just needs to 
> store an associative arrays that maps names of instance variables and 
> methods to their addresses. This could probably be stored in the 
> ClassInfo. Something like this:
>
> Foo.classinfo.setInstanceVariable(foo, "a", 3);
>
> And this could be shorted to:
>
> o.setInstanceVariable("a", 3);
>
> "setInstanceVariable" could just forward the call to the class info.
>

It's not /quite/ the same thing as you're asking, but I'm facing a 
problem that seems to fundamentally prevent dynamic typing to work 
correctly (which is related, but of course not the same thing as, 
reflection):
http://stackoverflow.com/questions/7102648/using-dynamic-typing-in-d-a-statically-typed-language

As much as I'd love to see it happen, I can't see how templates and 
reflection would actually work at run-time.