Re: [boost] FSM Review Announcement

From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2008-08-06 10:39:40

Michael Caisse wrote:
> Andrey Semashev wrote:
>>
>> I thought about nested states, but, the way I understand it, there are 
>> no advantages of nested states over nested state machines. Obviously, 
>> you can define as much FSMs as you like and nest them within states as 
>> you need.
>> _______________________________________________
> 
> Perhaps I don't understand your use of nesting FSMs within a state yet. 
> "Nested states" or hierarchical state machines can provide extremely 
> powerful semantics such as return-to-history.

Maybe I just misunderstand what you mean by "nested states". I 
understand it as a more detailed description of the machine condition. 
For example, we have electronic watches that show either current date or 
current time and while showing time the colon between hours and minutes 
is blinking. The top level states could be showing_date and 
showing_time, and showing_time could have nested states with_colon and 
without_colon. If this is what you call "nested states", then the 
approach is similar to having a separate FSM with states with_colon and 
without_colon within the showing_time state.