Updates when python min version is 3.9

[schloerke]

No description provided.

[schloerke]

• Add in WrapAsync generic class so that AsyncValueFn can inherit from it.

Definition:

class WrapAsync(Generic[P, R]):
    """
    Make a function asynchronous.

    Parameters
    ----------
    fn
        Function to make asynchronous.

    Returns
    -------
    :
        Asynchronous function (within the `WrapAsync` instance)
    """

    def __init__(self, fn: Callable[P, R] | Callable[P, Awaitable[R]]):
        if isinstance(fn, WrapAsync):
            fn = cast(WrapAsync[P, R], fn)
            return fn
        self._is_async = is_async_callable(fn)
        self._fn = wrap_async(fn)

    async def __call__(self, *args: P.args, **kwargs: P.kwargs) -> R:
        """
        Call the asynchronous function.
        """
        return await self._fn(*args, **kwargs)

    @property
    def is_async(self) -> bool:
        """
        Was the original function asynchronous?

        Returns
        -------
        :
            Whether the original function is asynchronous.
        """
        return self._is_async

    @property
    def fn(self) -> Callable[P, R] | Callable[P, Awaitable[R]]:
        """
        Retrieve the original function

        Returns
        -------
        :
            Original function supplied to the `WrapAsync` constructor.
        """
        return self._fn

Update AsyncValueFn to inherit from WrapAsync:

class AsyncValueFn(WrapAsync[[], IT]):
    ...

[wch]

Just curious: why does this Python 3.9?

[schloerke]

When inheriting from a class that has a ParamSpec, in Python >= 3.9 the paramspec can be defined as []. In python 3.8, it does not understand it and raises. You can pass in a P paramspec, but for the case of AsycnValueFn, the ParamSpec should be empty and I couldn't find a way to define it as empty.