Is Anything Holding you back?

[Jonas Drewsen via Digitalmars-d]

On Monday, 5 October 2015 at 06:18:45 UTC, Manu wrote:
> You can easily make attributes effectively available at runtime 
> by
> building lists of attributed things at compile time.
> I don't understand your problem. Describe the goal?

This is all nice but still not as slick as could be. Say a want 
to have a central place to lookup all classes with the Foo() 
attribute on it. The classes can be in several files of course so 
there are two ways of registering them at compile time to be 
available for runtime lookups:

1, Add a static module contructor to each module that registers 
the Foo() attribut'ed classes. This constructor is probably 
generated at compile time and mixed into the module as a 
one-liner.

2, Add a "registration" module that imports all other modules in 
order to filter out Foo() attributed classes and register them 
for runtime usage.

The first method is bad because you need to mixin code manually 
for each module you have.

The second method is bad because you need to keep the 
"registration" file in sync with any modules 
added/renamed/removed.

A couple of months ago I was working on an extension to the 
string import() feature of D: It would simply treat a import(*) 
as returning the directory listing of the imports path. From that 
the list of .d file could be figured out and imported at compile 
time. Then the the runtime information could be extracted at 
compile time with no fuzz.

/Jonas