From: Jim Weirich <jim@...>
Date: 2004-11-04T09:58:58+09:00
Subject: Re: fsmgen 0.1

On Wednesday 03 November 2004 11:34 am, Eivind Eklund wrote:
> Wouldn't this be better implemented as meta-programming in Ruby, 

Funny you should mention this ... I was playing with ruby state machines about 
two weeks ago (even using the turnstile example in my unit tests).  This is 
what I came up with ....

  class TurnStileFSM < StateMachine
    state_machine do
      state :locked do
        start_state
        event :coin, :unlocked,  :unlock
        event :pass, :violation, :alarm_on
      end
      state :unlocked do
        event :coin, :unlocked, :thank_you
        event :pass, :locked,   :lock
      end
      state :violation do
        event :reset, :violation
        event :ready, :locked, :alarm_off, :lock
        event :pass
        event :coin
      end
    end
  end

To use, you just inherit from the FSM and implement the actions (e.g. unlock, 
lock, alarm_on).   (Or I suppose you could implement the actions directly in 
the FSM class).

-- 
-- Jim Weirich    jim@weirichhouse.org     http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct, 
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)