Activity api

[maxfischer2781]

Changed the API of rich Activity class to be similar to "bare" activities (aka coroutines).

await activity  # await bare activity

async with Scope() as scope:
    await scope.do(activity) # construct and await rich activity

Key changes invert how to query and wait for completion:

• await activity.result => await activity returns the result (value or exception) on completion
• await activity => await acitvity.done delays until completion

[eileen-kuehn]

There only seem to be some minor issues with formulations. If those are fixed, we can merge :)

[eileen-kuehn]

Who can receive the notification? The activity? What about postponed activities?

[maxfischer2781]

Being postponed is a special case of being suspended. Should it be made clear that both apply?

[eileen-kuehn]

Ok, definition of Postponement and Suspension should maybe made more clear. You could put into the description of Postponement that this is a special case of being suspended. This might help.

[maxfischer2781]

I have changed the documentation for Activity to better distinguish between the underlying activity (coroutine, awaitable, ...) and the handle for it (an Activity instance). However, it may be better to have an entirely different name.

There is no real consensus in other async frameworks. The asyncio, trio and curio libraries use the term Task for generally the same concept. trio does not seem to allow getting the result or waiting for completion. curio uses Task.join to get the result, and Task.wait to await completion. asyncio only allows waiting for completion using await Task.

Since the Activity class is not meant to be used by-name, we could defer this for now.

[maxfischer2781]

The Activity class has been renamed to Task (see issue #3 ), and related classes are renamed as well (e.g. ActivityCancelled => TaskCancelled).