Python sum types for atdpy

example.py

from typing import List
import json

# type t = A | B of int

class T:
    pass

class T_A(T):
    def __repr__(self):
        return 'A'

    def to_json(self):
        return 'A'

    def to_json_string(self) -> str:
        return json.dumps(self.to_json())

class T_B(T):
    def __init__(self, value):
        self._value: int = value

    def __repr__(self):
        return f"B({self._value})"

    def value(self):
        return self._value

    def to_json(self):
        return ['B', self._value]

    def to_json_string(self) -> str:
        return json.dumps(self.to_json())

print("Testing __repr__")
things: List[T] = [T_A(), T_B(77)]
print(things)

print("Testing to_json_string")
print(T_A().to_json_string())
print(T_B(22).to_json_string())