More annoying for our codebase is the inability to specify optional/default arguments with closures. We often use functions that return other functions and you

More annoying for our codebase is the inability to specify optional/default arguments with closures. We often use functions that return other functions and you can't persist the "optional state" without using a protocol. It would be great just to match the current state of vanilla defs with optional params. For example: def make_fun1(a: int) -> Callable[[int, Optional[int]], str]: def fun(b: int, c: Optional[int] = None) -> str: if c: b += c return f"{a+b}" return fun fun = make_fun(1) fun(2) Will give you `Too few arguments` for `fun(2)` You can fix this with something like: class FunC(Protocol): def __call__(self, b: int, c: Optional[int] = None) -> str: ... def make_fun(a: int) -> FunC: ... But that that seems like unnecessary overhead, because the non-nested def case can happily understand the optional parameter.