typesafe-monads/monads/applicative.py

22 lines
691 B
Python

from __future__ import annotations
from typing import Any, Callable, TypeVar
from .functor import Functor
T = TypeVar("T")
S = TypeVar("S")
class Applicative(Functor[T]):
@classmethod
def pure(cls, value: T) -> Applicative[T]: # pragma: no cover
raise NotImplementedError
# FIXME: Functor type set to Any, as the proper value
# (Functor[Callable[[T], S]]) is reported as incompatible with subclass
# implementations due to a flaw in mypy:
# https://github.com/python/mypy/issues/1317
def apply(self, functor: Any) -> Functor[S]: # pragma: no cover
raise NotImplementedError
__and__ = lambda other, self: Applicative.apply(self, other)