Re: [boost] [msm] Review

Subject: Re: [boost] [msm] Review
From: David Bergman (David.Bergman_at_[hidden])
Date: 2009-12-05 13:09:58

On Dec 5, 2009, at 12:32 PM, Andreas Huber wrote:

>> Ignorant? Andreas, I can tell you one thing: I am anything but ignorant.
> 
> Ok, I'm listening. How well do you know Statechart? Have you read the tutorial? Have you read the rationale?

I have used it in two medium-sized projects (one BitTorrent-like client and one real-time auction engine, to keep track of the state of individual auctions.) Unfortunately, I have only toyed around with MSM the last few days. I know that the details differ between MSM and Statechart. So, I am much more knowledgeable about Statechart than what I am about MSM. I am quite knowledgeable about the theory and applications of FSMs, though, after a pair of decades of having forced teams to make explicit the state machines that often reside there implicitly (or at least intrinsically in the problem.)

But, over these years, when using C++, I have almost always used our own implementations of state machines. Dare I say this: it is not the most tricky notion to implement, if one (i) is not that worried about the performance (say, not that many hundred transitions per second) or (ii) in need of nested states; and, this I dare say: it is also a quite rewarding task and fun!

Yes, I know that both Statechart and MSM care about these aspects, which have *mostly* been a non-concern for my applications. Honestly, the nested FSMs have often been implemented ad hoc ;-)

/David