gistfile1.rb

require 'finite_machine'
require 'pp'

class StopLight < FiniteMachine::Definition
   events {
      initial :red
      event :power_on, :off => :red
#      event :power_off, :any => :off
      event :power_off, [:on, :red, :green, :yellow]  => :off
      event :change, :red    => :green
      event :change, :green  => :yellow
      event :change, :yellow => :red
   }
   callbacks {
      on_transition do |event|
         pp event
      end
   }
end


sl = StopLight.new

loop do
   puts "***Change"
   sl.change
   if rand(5) == 0
      puts "*** Whoops. Lost power!"
      sl.power_off
   end
   sleep 1
   puts
end