Re: [Boost-users] [statechart]historytransitionsmakestate-local-storage "un-cool"

On Tue, Jun 24, 2008 at 1:37 AM, Felipe Magno de Almeida wrote:

On Mon, Jun 23, 2008 at 6:18 PM, Andreas Huber wrote:

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"Felipe Magno de Almeida" wrote in message news:a2b17b60806211502i447c22e1t9d552dd76b8972a1@mail.gmail.com...

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If someone wants to pass arguments to X, then they should transit to X, and X transit to Y IMHO.

Transiting to X could be semantically different from transiting to Y. In the diagram discussed so far it's not but looking at the transitions triggered by e3 and e4 in ...

http://i.cmpnet.com/embedded/gifs/9901/9901feat1fig4.gif

... you'll see an example where it is. Transiting to S0 leads to the entry of S0 and S0_1 while transiting to S0_2 leads to the entry of S0 and S0_2.

I understand. But if someone is trying to transit directly to an inner state, does he care about the local-state of the new outer state? This is not rhetorical actually, I'm a little inexperienced with developing state machines. So far I've writed a SMTP client with asio, and am creating a SMTP server. I have no other experience with state machines.

Actually, I have myself an use case for passing arguments to outer states. I'm just throwing here a suggestion: How about having another way of transiting in this case? cascate_transit<state1>(inner_arg1, inner_arg2) .outer<state2>(middle_arg1, middle_arg2) .outer<state3>(outer_arg1, middle_arg2); template struct cascate_transit; struct typename State0, nil, nil, ..> { template cascate_transit operator()(A0, A1) const; }; I don't know how to get a functor to the code that instantiates the state, nor I know where it is instantiated. But I can implement the commands that get the arguments without problem, if you're willing to have this added to statechart. And completely off-topic: Also, a state that is instantiated through tss (when multithreaded), or through a global variable (when single-threaded) could be good. This is how I have the implementation windows initialized in my cppgui library before the derived user classes. Without requiring the user to pass along a context. [snip] -- Felipe Magno de Almeida