Andreas Huber <ah2003@gmx.net> writes:
Exits happen before entries, and you can't undo an exit; that's status quo. If you get arrive at the point where an entry is about to fail, then the preceding exit didn't fail, so the possibility of a failing exit has no impact.
As I have tried to explain before: The problem lies in the fact that you can have multiple exit actions called in a row before entry actions are called. If e.g. the second of those exit actions fails (the first one succeeded) then your state machine is in an invalid state from where it is impossible to recover. What exactly is the loophole/problem/circularity in this reasoning?
It seems to me that part of the problem lies in how you define "recover". You seem to think that if an *entry* action fails after exiting a state there is a sensible meaning of "recover" that can always be achieved, while if a (2nd) exit action fails in the same circumstances no sensible recovery is possible. I don't understand how that can be, but as I've said many times, I'm probably missing something. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com