HSM

gistfile1.rb

# 1 state 1 block
module Hsm
   class Event
      def initialize(name)
         @name = name
      end
   end

   # system events
   INIT = Event.new('INIT')
   ENTER = Event.new('ENTER')
   EXIT = Event.new('EXIT')
   SUPER = Event.new('SUPER')

   module Machine
      def initHsm
         @states = {}
         @cur = nil
      end

      def register(name, &block)
         @states[name] = block
      end

      def start(name)
         # TODO 順に入っていく
         @cur = name
         dispatch(ENTER)
      end

      def to_top(from)
         a = []
         s = from
         while s != :top
            a << s
            s = _super(s)
         end
         a << :top
      end

      def lca(from, to)
         l = :top
         i = 0
         while true
            if from[i] != to[i]
               break
            else
               l = from[i]
            end
            i += 1
         end
         l
      end

      # TODO おかしい気がする？ cur != src
      def trans(dest)
         #puts "TRANS: from=#{@cur.inspect} to=#{dest.inspect}"
         if @cur == dest
            trigger(@cur, EXIT)
            trigger(dest, ENTER)
         else
            cur2top = to_top(@cur)
            dest2top = to_top(dest)

            ancestor = lca(cur2top.reverse, dest2top.reverse)
            #puts "lca=#{ancestor.inspect}"

            # EXIT: cur -> lca
            cur2top[0, cur2top.index(ancestor)].each do |s|
               trigger(s, EXIT)
            end

            # ENTER: lca -> dest
            dest2top[0, dest2top.index(ancestor)].reverse.each do |s|
               trigger(s, ENTER)
            end

            @cur = dest
         end
      end

      def trigger(state, event)
         @states[state].call(event)
      end

      def _super(state)
         @states[state].call(SUPER)
      end

      def dispatch(event)
         st = @cur
         while true
            #puts "START DISPATCH: st=#{st.inspect} ev=#{event.inspect}"
            s = trigger(st, event)
            #puts "return = #{s.inspect}"
            if s != 0 and s != :top
               st = s
            else
               break
            end
         end
         #puts "END DISPATCH"
      end
   end
end

if __FILE__ == $0

   #main

   #define events
   module Hsm
      TIRE = Event.new('TIRE')
      ALERM = Event.new('ALERM')
   end

   # define state machine
   class MyMachine
      include Hsm::Machine

      def initialize
         init

         register(:sleeping) do |e|
            puts @cur.inspect + ' ' + e.inspect
            case e
            when Hsm::ENTER
               puts 'sleep.'
               next 0
            when Hsm::TIRE
               puts 'sleeping.'
               next 0
            when Hsm::ALERM
               puts 'ooohh'
               trans(:sitting)
               next 0
            when Hsm::EXIT
               puts 'awake?.'
               next 0
            end
            next :top
         end

         register(:awake) do |e|
            puts @cur.inspect + ' ' + e.inspect
            case e
            when Hsm::ENTER
               puts 'awake.'
               next 0
            when Hsm::TIRE
               puts 'im tired.'
               trans(:sitting)
               next 0
            when Hsm::ALERM
               puts 'uuum?'
               next 0
            when Hsm::EXIT
               puts 'dance end.'
               next 0
            end
            next :top
         end

         register(:dancing) do |e|
            puts @cur.inspect + ' ' + e.inspect
            case e
            when Hsm::SUPER
               next :awake
            when Hsm::ENTER
               puts 'dance start.'
               next 0
            when Hsm::TIRE
               puts 'im tired.'
               trans(:sitting)
               next 0
            when Hsm::EXIT
               puts 'dance end.'
               next 0
            end
            next :awake
         end

         register(:sitting) do |e|
            puts @cur.inspect + ' ' + e.inspect
            case e
            when Hsm::SUPER
               next :awake
            when Hsm::ENTER
               puts 'start sitting.'
               next 0
            when Hsm::TIRE
               puts 'yes, im tired yet.'
               trans(:sleeping)
               next 0
            when Hsm::EXIT
               puts 'end sitting.'
               next 0
            end
            next :awake
         end

         start(:dancing)
      end
   end

   m = MyMachine.new
   m.dispatch(Hsm::ALERM)
   m.dispatch(Hsm::TIRE)
   m.dispatch(Hsm::TIRE)
   m.dispatch(Hsm::ALERM)

end