Source code for returns.pointfree.apply

from typing import Callable, TypeVar

from returns.interfaces.applicative import ApplicativeN
from import Kinded, KindN, kinded

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

_ApplicativeKind = TypeVar('_ApplicativeKind', bound=ApplicativeN)

[docs]def apply( container: KindN[ _ApplicativeKind, Callable[[_FirstType], _UpdatedType], _SecondType, _ThirdType, ], ) -> Kinded[Callable[ [KindN[_ApplicativeKind, _FirstType, _SecondType, _ThirdType]], KindN[_ApplicativeKind, _UpdatedType, _SecondType, _ThirdType], ]]: """ Turns container containing a function into a callable. In other words, it modifies the function signature from: ``Container[a -> b]`` to: ``Container[a] -> Container[b]`` This is how it should be used: .. code:: python >>> from returns.pointfree import apply >>> from returns.maybe import Some, Nothing >>> def example(argument: int) -> int: ... return argument + 1 >>> assert apply(Some(example))(Some(1)) == Some(2) >>> assert apply(Some(example))(Nothing) == Nothing >>> assert apply(Nothing)(Some(1)) == Nothing >>> assert apply(Nothing)(Nothing) == Nothing Note, that this function works for all containers with ``.apply`` method. See :class:`returns.interfaces.applicative.ApplicativeN` for more info. """ @kinded def factory( other: KindN[_ApplicativeKind, _FirstType, _SecondType, _ThirdType], ) -> KindN[_ApplicativeKind, _UpdatedType, _SecondType, _ThirdType]: return other.apply(container) return factory