Source code for returns.pointfree.bind_result

from __future__ import annotations

from typing import TYPE_CHECKING, Callable, TypeVar

from returns.interfaces.specific.result import ResultLikeN
from import Kinded, KindN, kinded

    from returns.result import Result  # noqa: WPS433

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

_ResultLikeKind = TypeVar('_ResultLikeKind', bound=ResultLikeN)

[docs]def bind_result( function: Callable[[_FirstType], Result[_UpdatedType, _SecondType]], ) -> Kinded[Callable[ [KindN[_ResultLikeKind, _FirstType, _SecondType, _ThirdType]], KindN[_ResultLikeKind, _UpdatedType, _SecondType, _ThirdType], ]]: """ Composes successful container with a function that returns a container. In other words, it modifies the function's signature from: ``a -> Result[b, c]`` to: ``Container[a, c] -> Container[b, c]`` .. code:: python >>> from import IOSuccess >>> from returns.context import RequiresContextResult >>> from returns.result import Result, Success >>> from returns.pointfree import bind_result >>> def returns_result(arg: int) -> Result[int, str]: ... return Success(arg + 1) >>> bound = bind_result(returns_result) >>> assert bound(IOSuccess(1)) == IOSuccess(2) >>> assert bound(RequiresContextResult.from_value(1))(...) == Success(2) """ @kinded def factory( container: KindN[_ResultLikeKind, _FirstType, _SecondType, _ThirdType], ) -> KindN[_ResultLikeKind, _UpdatedType, _SecondType, _ThirdType]: return container.bind_result(function) return factory