What if a method has two or more union args?

((Foo or Bar or Baz) arg1, (X or Y or Z) arg2)

You want to generate 12 overloads?

Also union can be dictionary member and return type. What would do they look like?

Yes, I'd like us to have all the C++ combinations enumerated. If you need to call the method from C++ it should call based on the correct type pattern. How many of those very long ones exist in practice though?

For dictionaries I think we should consider exposing the type checking methods on the Dictionary. For return types we can expose a type + wrapper and the bindings can handle the unwrapping if needed.

ex. return UnionType<X>, and people can check by doing .is(X::Type) or some such.

Code generating huge unions is bad. We can do it with templates and type fields.

Using wrapper (variadic template args) is what I was tried first to fix dependency cycles. I just gave up bacause it's difficult for me to implement in 2-3 days :(

btw, we discussed the design before.
https://docs.google.com/a/chromium.org/document/d/1hBBFlueguEELjBqN_csSIxj7te1KmOafl9_vvVTO0J0/edit?usp=docslist_api

I agree with huge unions are not good, but not sure we want to add extra logic for union overloads.

yukishiino@ FYI

Yeah, that was a few years ago though, and we're older and wiser now. We're also pushing for things like webmodules and being more primitive based. :)