Method apply

returns/io.py:404–441

Calls a wrapped function in a container on this container. .. code:: python >>> from returns.io import IOSuccess, IOFailure >>> def appliable(first: str) -> str: ... return first + 'b' >>> assert IOSuccess('a').apply( ...

(
        self,
        container: Kind2[
            'IOResult',
            Callable[[_ValueType_co], _NewValueType],
            _ErrorType_co,
        ],
    )

        return self.from_result(self._inner_value.map(function))

    def apply(
        self,
        container: Kind2[
            'IOResult',
            Callable[[_ValueType_co], _NewValueType],
            _ErrorType_co,
        ],
    ) -> 'IOResult[_NewValueType, _ErrorType_co]':
        """
        Calls a wrapped function in a container on this container.

        .. code:: python

          >>> from returns.io import IOSuccess, IOFailure

          >>> def appliable(first: str) -> str:
          ...      return first + 'b'

          >>> assert IOSuccess('a').apply(
          ...     IOSuccess(appliable),
          ... ) == IOSuccess('ab')
          >>> assert IOFailure('a').apply(
          ...     IOSuccess(appliable),
          ... ) == IOFailure('a')

          >>> assert IOSuccess('a').apply(IOFailure(1)) == IOFailure(1)
          >>> assert IOFailure('a').apply(IOFailure('b')) == IOFailure('a')

        """
        if isinstance(self, IOFailure):
            return self
        if isinstance(container, IOSuccess):
            return self.from_result(
                self._inner_value.map(
                    container.unwrap()._inner_value,  # noqa: SLF001
                ),
            )
        return container  # type: ignore

    def bind(
        self,