Source code for returns._generated.pointfree.bind_ioresult
def _bind_ioresult(function):
"""
Lifts function returning ``IOResult`` to be wrapped in another container.
In other words, it modifies the function's
signature from: ``a -> IOResult[b, c]``
to: ``Container[a, c] -> Container[b, c]``
This is how it should be used:
.. code:: python
>>> import anyio
>>> from returns.future import FutureResult
>>> from returns.io import IOSuccess, IOFailure, IOResult
>>> from returns.pointfree import bind_ioresult
>>> def example(argument: int) -> IOResult[float, int]:
... return IOSuccess(argument / 2)
>>> async def success() -> FutureResult[float, int]:
... container = FutureResult.from_value(1)
... return await bind_ioresult(example)(container)
>>> async def failure() -> FutureResult[float, int]:
... container = FutureResult.from_failure(1)
... return await bind_ioresult(example)(container)
>>> assert anyio.run(success) == IOSuccess(0.5)
>>> assert anyio.run(failure) == IOFailure(1)
And with sync code:
.. code:: python
>>> from returns.context import RequiresContextIOResult
>>> def function(arg: int) -> IOResult[str, int]:
... if arg > 0:
... return IOSuccess(str(arg) + '!')
... return IOFailure(arg)
>>> deps = RequiresContextIOResult.empty
>>> assert bind_ioresult(function)(
... RequiresContextIOResult.from_value(1),
... )(deps) == IOSuccess('1!')
>>> assert bind_ioresult(function)(
... RequiresContextIOResult.from_value(0),
... )(deps) == IOFailure(0)
>>> assert bind_ioresult(function)(
... RequiresContextIOResult.from_failure('nope'),
... )(deps) == IOFailure('nope')
"""
return lambda container: container.bind_ioresult(function)