Add an Action interface

[sygour]

The Reducer, Dispatcher and Middleware handle the Object type.
When using it inside a project it could be a really handy thing to have an interface for marking our actions.
Of course, the interface would be empty.

I can't make a pull request right now, so if someone thinks it's a good idea and wants to do it, feel free!

[AngusMorton]

Can you provide an example of a case where the empty marker interface is more useful than the Object typed actions in the API?

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On Sat, 12 Aug 2017, 11:36 PM Sylvain ***@***.***> wrote: The Reducer, Dispatcher and Middleware handle the Object type. When using it inside a project it could be a really handy thing to have an interface for marking our actions. Of course, the interface would be empty. I can't make a pull request right now, so if someone thinks it's a good idea and wants to do it, feel free! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#19>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AGrA9JeEhWpsTw-gYvPWvgy3R7zx51Nhks5sXapIgaJpZM4O1am7> .

[sygour]

It's not more useful per se but it could be help the API and the use of it to handle purposely declared actions instead of any java object.

I guess in some project with the current API, action classes may be named DoSomethingAction or put in an action package. By forcing the type of the received Object, you can just look up what implements the Action interface and you'd have all your actions.

One personal thought also:
On an purely API level, inputs and outputs of the API should be as much as possible types defined in the API. That way the implementing and using projects can control what comes in and out. But again, this one is a personal thought.