On Tue, Jun 24, 2008 at 1:37 AM, Felipe Magno de Almeida <felipe.m.almeida@gmail.com> wrote:
On Mon, Jun 23, 2008 at 6:18 PM, Andreas Huber <ahd6974-spamboostorgtrap@yahoo.com> wrote:
"Felipe Magno de Almeida" <felipe.m.almeida@gmail.com> wrote in message news:a2b17b60806211502i447c22e1t9d552dd76b8972a1@mail.gmail.com...
[snip]
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 <typename State0, typename State1 = nil, typename State2 = nil, ...> struct cascate_transit; struct typename State0, nil, nil, ..> { template <typename OuterState, typename A0, typename A1, ...> cascate_transit<State0, OuterState> 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