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Subject: Re: snc/seq enhancements ... local-variable access
From: Eric Norum <norume@aps.anl.gov>
To: "Laznovsky, Michael" <lazmo@slac.stanford.edu>
Cc: Tim Mooney <mooney@aps.anl.gov>, tech-talk@aps.anl.gov
Date: Thu, 6 Apr 2006 13:48:43 -0500
I agree with Michael that turning seq from a DFA into an arbitrary procedural language interpreter is not a good thing.

On Apr 6, 2006, at 1:09 PM, Laznovsky, Michael wrote:

Hi- while this might be fairly easy to do given the way seq does its
internal bookkeeping, seems to me it would muck up the relatively clean
DFA state-machine model we have now. I've handled cases like you describe
(e.g. an "ABORT" button that allows interrupting a long series of states)
by adding extra intermediate states, as in:


	state A
	{
		entry {
			flag = OK;
		}
		when (<event>) {
			if (trouble) flag = BUBU;
		} state A_check
	}

	state A_check
	{
		when (flag == BUBU) {		/* uh oh! */
		} state A_abort
	
		when () {
		} state B				/* next state */
	}

The "out-of-order" transitions I mentioned referred to a future debugging
environment, where it might be useful to interactively force a transition
to an arbitrary state.




-- Eric Norum <norume@aps.anl.gov> Advanced Photon Source Argonne National Laboratory (630) 252-4793



Replies:
Re: snc/seq enhancements ... local-variable access Tim Mooney
References:
RE: snc/seq enhancements ... local-variable access Laznovsky, Michael

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