Source code for returns.pointfree.bind_context_ioresult
from __future__ import annotations
from typing import TYPE_CHECKING, Callable, TypeVar
from returns.interfaces.specific.reader_ioresult import ReaderIOResultLikeN
from returns.primitives.hkt import Kinded, KindN, kinded
if TYPE_CHECKING:
from returns.context import ReaderIOResult # noqa: WPS433
_FirstType = TypeVar('_FirstType')
_SecondType = TypeVar('_SecondType')
_ThirdType = TypeVar('_ThirdType')
_UpdatedType = TypeVar('_UpdatedType')
_ReaderIOResultLikeKind = TypeVar(
'_ReaderIOResultLikeKind',
bound=ReaderIOResultLikeN,
)
[docs]def bind_context_ioresult(
function: Callable[
[_FirstType],
ReaderIOResult[_UpdatedType, _SecondType, _ThirdType],
],
) -> Kinded[Callable[
[KindN[_ReaderIOResultLikeKind, _FirstType, _SecondType, _ThirdType]],
KindN[_ReaderIOResultLikeKind, _UpdatedType, _SecondType, _ThirdType],
]]:
"""
Lifts function from ``RequiresContextIOResult`` for better composition.
In other words, it modifies the function's
signature from:
``a -> RequiresContextIOResult[env, b, c]``
to:
``Container[env, a, c]`` -> ``Container[env, b, c]``
.. code:: python
>>> import anyio
>>> from returns.context import (
... RequiresContextFutureResult,
... RequiresContextIOResult,
... )
>>> from returns.io import IOSuccess, IOFailure
>>> from returns.pointfree import bind_context_ioresult
>>> def function(arg: int) -> RequiresContextIOResult[str, int, str]:
... return RequiresContextIOResult(
... lambda deps: IOSuccess(len(deps) + arg),
... )
>>> assert anyio.run(bind_context_ioresult(function)(
... RequiresContextFutureResult.from_value(2),
... )('abc').awaitable) == IOSuccess(5)
>>> assert anyio.run(bind_context_ioresult(function)(
... RequiresContextFutureResult.from_failure(0),
... )('abc').awaitable) == IOFailure(0)
"""
@kinded
def factory(
container: KindN[
_ReaderIOResultLikeKind,
_FirstType,
_SecondType,
_ThirdType,
],
) -> KindN[_ReaderIOResultLikeKind, _UpdatedType, _SecondType, _ThirdType]:
return container.bind_context_ioresult(function)
return factory