Source code for returns.pointfree.bind_context_result

from __future__ import annotations

from typing import TYPE_CHECKING, Callable, TypeVar

from returns.interfaces.specific.reader_result import ReaderResultLikeN
from returns.primitives.hkt import Kinded, KindN, kinded

if TYPE_CHECKING:
    from returns.context import ReaderResult  # noqa: WPS433

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

_ReaderResultLikeKind = TypeVar(
    '_ReaderResultLikeKind',
    bound=ReaderResultLikeN,
)


[docs]def bind_context_result( function: Callable[ [_FirstType], 'ReaderResult[_UpdatedType, _SecondType, _ThirdType]', ], ) -> Kinded[Callable[ [KindN[_ReaderResultLikeKind, _FirstType, _SecondType, _ThirdType]], KindN[_ReaderResultLikeKind, _UpdatedType, _SecondType, _ThirdType], ]]: """ Composes successful container with a function that returns a container. In other words, it modifies the function's signature from: ``a -> ReaderResult[b, c, e]`` to: ``Container[a, c, e] -> Container[b, c, e]`` .. code:: python >>> from returns.pointfree import bind_context_result >>> from returns.context import ReaderIOResult, ReaderResult >>> from returns.io import IOSuccess, IOFailure >>> def example(argument: int) -> ReaderResult[int, str, str]: ... return ReaderResult.from_value(argument + 1) >>> assert bind_context_result(example)( ... ReaderIOResult.from_value(1), ... )(...) == IOSuccess(2) >>> assert bind_context_result(example)( ... ReaderIOResult.from_failure('a'), ... )(...) == IOFailure('a') """ @kinded def factory( container: KindN[ _ReaderResultLikeKind, _FirstType, _SecondType, _ThirdType, ], ) -> KindN[_ReaderResultLikeKind, _UpdatedType, _SecondType, _ThirdType]: return container.bind_context_result(function) return factory