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Subject: Re: [boost] [msm] eUML guard/action location
From: Michael Caisse (boost_at_[hidden])
Date: 2009-12-08 11:40:28

Stewart, Robert wrote:
> With whitespace, I agree that there's little difference between the two.
> Here's another suggestion, though it breaks from the logical UML ordering Michael posted previously:
> DestState() = CurrentState() + cool_event()[guard()]/(action())
> This is in keeping with Spirit's syntax in that the guard/action expression is positioned like a semantic action. It also reads better in C++ because we think in terms of evaluating the RHS and assigning the result to the LHS, and the RHS results in the state on the LHS in the above syntax.

Rob -

I actually like this quite a bit.

  1. it keeps the event/guard/action with the source state
  2. the '=' read funny to me in the other. Here it actually
     reads "properly". RHS is evaluated and becomes LHS.

Nice suggestion.


Michael Caisse
Object Modeling Designs

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