Failed attempt at higher kinded types in python :P

failed_hkt.py

from typing import TypeVar, Generic

F = TypeVar("F")
A = TypeVar("A")


class Kind(Generic[F, A]):

    def __init__(self: F):
        self.hkt = self


class Box(Kind["Box[A]", A]):

    def __init__(self, val: A):
        super(Box, self).__init__()
        self.val = val

    def get(self) -> A:
        return self.val


def stringify(val: Kind[F, int]) -> Kind[F, str]: ...

b = Box(123)

reveal_type(b) # Box[int]
reveal_type(b.get()) # int
reveal_type(b.hkt) # Box[int]
reveal_type(b.hkt.get()) # int

c = stringify(b)
reveal_type(c) # Kind[Box, str]
reveal_type(c.hkt.get()) # int.. DAMN

overload_hkt.py

from typing import TypeVar, Generic, overload, List

F = TypeVar("F")
A = TypeVar("A")


class Kind(Generic[F, A]):
    ...


class Box(Kind["Box", A]):
    def __init__(self, val: A):
        super(Box, self).__init__()
        self.val = val

    def get(self) -> A:
        return self.val


# Can this be more generic? Can we define these where we also define Kinded classes?
@overload
def dekind(kind: Kind[Box, A]) -> Box[A]:
    ...


@overload
def dekind(kind: Kind[List, A]) -> List[A]:
    ...


def dekind(kind):
    return kind


def stringify(val: Kind[F, int]) -> Kind[F, str]:
    ...


b = Box(123)

reveal_type(b)  # Box[int]
reveal_type(b.get())  # int

c = dekind(stringify(b))
reveal_type(c)  # Box[str]
reveal_type(c.get())  # str