On Saturday, 19 October 2024 at 08:51:20 UTC, Noé Falzon wrote:
tl;dr: is it possible to iterate over all classes in a program
at compile time (or possibly all derived classes from a given
base class) to use in a mixin?
No, parent class can not possibly know who extends it, just think
about dynamic libraries...
And unfortunately there is no single place to know every possible
module used in a build for various reasons, the closest thing you
can do is obtain modules present in a separate compilation unit,
i.e. a module with its imports.
as seen with 'dummy' module parent, you cannot get above it.
in this case dummy module is here, but if for example I also had
another module I can't access it this way without importing it
some way or another.
```d
import std.stdio;
import std.algorithm;
import dummy;
enum foo = "we need foo just to get something accessible in this
module";
pragma(msg, __traits(allMembers, __traits(parent, foo))); //
prints AliasSeq!("object", "std", "dummy", "foo")
//pragma(msg, __traits(allMembers, __traits(parent, dummy))); //
Error: argument `dummy` has no parent
```
The closest I got so far is to generate the list of names with
a pre-build command that greps through the sources for relevant
class names, and a file import:
The only improvement to this I can think of is to use D AST
parser that reliably understands code structure.
The example of this you can find in godot-d class finder, other
than that it works exactly same.
https://github.com/godot-dlang/godot-dlang/blob/534024c7e27522d6120a9b64e8ef183b79416539/modules/tools/classfinder/godot/tools/classfinder/package.d
Just in case, there is a possible way to get modules at RUNTIME,
and from there ModuleInfo has list of classes and other type
information.
https://dlang.org/phobos/object.html#.ModuleInfo.localClasses
```d
import std.stdio;
void main() {
// ModuleInfo without parenthesis will call opDelegate to
acquire list of modules known at runtime
foreach(m; ModuleInfo) {
writeln(m.name);
}
}
```
prints
rt.lifetime
rt.dmain2
core.internal.gc.proxy
rt.deh_win64_posix
core.exception
...
