Andreas Huber wrote:
David Abrahams wrote:
"Andreas Huber" <ah2003@gmx.net> writes:
Wow! So simple and yet powerful. It naturally supports nested states and polymorphic events. I guess this could quite easily be developed into a fast & lightweight boost::fsm alternative. Cool!
It's very close to the organization of the MPL FSM samples I have posted in the past...
I saw them. They are cool :)
Yep, I had noticed that. What I like better about Alexander's approach is that the transition table is implemented with ordinary C++ what makes it quite a bit more expressive than the MPL collections you used in your examples. Don't get me wrong, I personally love MPL, but I've found that the average programmer is easily scared away with even very simple MPL constructs.
I didn't expected that simplicity. In order to check my ideas I need some metaprogramming. For example, if I number every call-operator (overload_id<N> in a first argument), I can collect all states automatically (unique_at algorithm). I can also collect all events (unique_at again) and move transition table for those events to cpp file if a user puts static initializer in Fsm class. I can also check with find_if and is_convertible if there is a match for given state and event. If not, I can dispatch to alternative. If you have other ideas, please share them with me. I'm really interested to make implementation more complex :)
only there's no dumb O(N) for_each dispatching in my samples: they're O(1).
Unless I'm missing something one could easily modify Alexander's code to be O(1) too...?
Yep -- Alexander Nasonov