Re: [boost] [statechart] Completion transitions again.

From: Leandro Lucarella (llucarella_at_[hidden])
Date: 2007-08-31 13:04:46

Andreas Huber wrote:
>> struct ev: sc::event< ev > {};
>> struct B;
>> struct C;
>> struct A: sc::simple_state< A, Machine >
>> {
>>      typedef mpl::list<
>>              sc::completion_transition< >,
>>              sc::custom_reaction< ev >
>>          > reactions;
>>      sc::result react(const completion_event&)
>>      {
>>          if (guard)
>>              return transit< B >();
>>          return discard_event();
>>      }
>>      sc::result react(const ev&)
>>      {
>>          if (!guard)
>>              return transit< C >();
>>          return discard_event();
>>      }
>> };
> 
> I'm not sure how this is an improvement over the choice-point-like
> class?

It improves readability and removes the need for a dummy intermediate class?

> Again, this limitation can be overcome easily with the same trick.
> Specify a dummy outermost state as initial state and then post an event in the
> entry action that will trigger a transition to the desired state.

Ok, my main problem is gone. I can now express what I need with the 
intermediate dummy state trick.

I think the improvements in this limitations are desirable but not 
critical, and maybe you are right and it's too much work for too little 
gain.

Thanks for your help!

-- 
Leandro Lucarella
Integratech S.A.
4571-5252