Using haxe component from Html5/JS


I am experimenting with Haxe for creating a component that will be used in a bigger Html5 project.
Other than the @:expose keyword, I could not find any docs or samples for Haxe interop from JS.

So I know how to instantiate a class form JS and calling its methods, but what about extending Haxe classes from JS, or implementing interfaces, etc.?

Anybody has any suggestion, or samples for doing anything like that?

I would look at the generated source, see how Haxe does it, and whether it seems to make sense to do by hand