Source code for returns.pointfree.bind_async_future

from typing import Awaitable, Callable, TypeVar

from returns.future import Future
from returns.interfaces.specific.future import FutureLikeN
from returns.primitives.hkt import Kinded, KindN, kinded

_FirstType = TypeVar('_FirstType')
_SecondType = TypeVar('_SecondType')
_ThirdType = TypeVar('_ThirdType')
_UpdatedType = TypeVar('_UpdatedType')

_FutureKind = TypeVar('_FutureKind', bound=FutureLikeN)


[docs]def bind_async_future( function: Callable[ [_FirstType], Awaitable[Future[_UpdatedType]], ], ) -> Kinded[Callable[ [KindN[_FutureKind, _FirstType, _SecondType, _ThirdType]], KindN[_FutureKind, _UpdatedType, _SecondType, _ThirdType], ]]: """ Compose a container and async function returning ``Future``. In other words, it modifies the function signature from: ``a -> Awaitable[Future[b]]`` to: ``Container[a] -> Container[b]`` This is how it should be used: .. code:: python >>> import anyio >>> from returns.pointfree import bind_async_future >>> from returns.future import Future >>> from returns.io import IO >>> async def example(argument: int) -> Future[int]: ... return Future.from_value(argument + 1) >>> assert anyio.run( ... bind_async_future(example)(Future.from_value(1)).awaitable, ... ) == IO(2) Note, that this function works for all containers with ``.bind_async_future`` method. See :class:`returns.primitives.interfaces.specific.future.FutureLikeN` for more info. """ @kinded def factory( container: KindN[_FutureKind, _FirstType, _SecondType, _ThirdType], ) -> KindN[_FutureKind, _UpdatedType, _SecondType, _ThirdType]: return container.bind_async_future(function) return factory