Method do

returns/future.py:353–382

Allows working with unwrapped values of containers in a safe way. .. code:: python >>> import anyio >>> from returns.future import Future >>> from returns.io import IO >>> async def main() -> bool: ... return await Future.do(

(
        cls,
        expr: AsyncGenerator[_NewValueType, None],
    )

    @classmethod
    def do(
        cls,
        expr: AsyncGenerator[_NewValueType, None],
    ) -> 'Future[_NewValueType]':
        """
        Allows working with unwrapped values of containers in a safe way.

        .. code:: python

          >>> import anyio
          >>> from returns.future import Future
          >>> from returns.io import IO

          >>> async def main() -> bool:
          ...     return await Future.do(
          ...         first + second
          ...         async for first in Future.from_value(2)
          ...         async for second in Future.from_value(3)
          ...     ) == IO(5)

          >>> assert anyio.run(main) is True

        See :ref:`do-notation` to learn more.

        """

        async def factory() -> _NewValueType:
            return await anext(expr)

        return Future(factory())

    @classmethod
    def from_value(cls, inner_value: _NewValueType) -> 'Future[_NewValueType]':