Source code for returns.interfaces.specific.future_result

Represents the base interfaces for types that do fear-some async operations.

This type means that ``FutureResult`` can (and will!) fail with exceptions.

Use this type to mark that this specific async opetaion can fail.

from __future__ import annotations

from abc import abstractmethod
from typing import TYPE_CHECKING, Awaitable, Callable, NoReturn, TypeVar

from returns.interfaces.specific import future, ioresult
from import KindN

    from returns.future import Future, FutureResult  # noqa: WPS433

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

_ValueType = TypeVar('_ValueType')
_ErrorType = TypeVar('_ErrorType')

_FutureResultLikeType = TypeVar(
    '_FutureResultLikeType', bound='FutureResultLikeN',

[docs]class FutureResultLikeN( future.FutureLikeN[_FirstType, _SecondType, _ThirdType], ioresult.IOResultLikeN[_FirstType, _SecondType, _ThirdType], ): """ Base type for ones that does look like ``FutureResult``. But at the time this is not a real ``Future`` and cannot be awaited. It is also cannot be unwrapped, because it is not a real ``IOResult``. """ __slots__ = ()
[docs] @abstractmethod def bind_future_result( self: _FutureResultLikeType, function: Callable[ [_FirstType], FutureResult[_UpdatedType, _SecondType], ], ) -> KindN[_FutureResultLikeType, _UpdatedType, _SecondType, _ThirdType]: """Allows to bind ``FutureResult`` functions over a container."""
[docs] @abstractmethod def bind_async_future_result( self: _FutureResultLikeType, function: Callable[ [_FirstType], Awaitable[FutureResult[_UpdatedType, _SecondType]], ], ) -> KindN[_FutureResultLikeType, _UpdatedType, _SecondType, _ThirdType]: """Allows to bind async ``FutureResult`` functions over container."""
[docs] @classmethod @abstractmethod def from_failed_future( cls: type[_FutureResultLikeType], # noqa: N805 inner_value: Future[_ErrorType], ) -> KindN[_FutureResultLikeType, _FirstType, _ErrorType, _ThirdType]: """Creates new container from a failed ``Future``."""
[docs] @classmethod def from_future_result( cls: type[_FutureResultLikeType], # noqa: N805 inner_value: FutureResult[_ValueType, _ErrorType], ) -> KindN[_FutureResultLikeType, _ValueType, _ErrorType, _ThirdType]: """Creates container from ``FutureResult`` instance."""
#: Type alias for kinds with two type arguments. FutureResultLike2 = FutureResultLikeN[_FirstType, _SecondType, NoReturn] #: Type alias for kinds with three type arguments. FutureResultLike3 = FutureResultLikeN[_FirstType, _SecondType, _ThirdType]
[docs]class FutureResultBasedN( future.FutureBasedN[_FirstType, _SecondType, _ThirdType], FutureResultLikeN[_FirstType, _SecondType, _ThirdType], ): """ Base type for real ``FutureResult`` objects. They can be awaited. Still cannot be unwrapped. """ __slots__ = ()
#: Type alias for kinds with two type arguments. FutureResultBased2 = FutureResultBasedN[_FirstType, _SecondType, NoReturn] #: Type alias for kinds with three type arguments. FutureResultBased3 = FutureResultBasedN[_FirstType, _SecondType, _ThirdType]