module Register

  #  collect anything that is in the space but and reachable from init
  module Collector
    def collect_space
      @objects.clear
      keep Parfait.object_space , 0
      constants.each {|obj| keep(obj,0)}
    end

    def keep object , depth
      return if object.nil?
      #puts "adding #{' ' * depth}:#{object.class}"
      #puts "ADD #{object.inspect}, #{object.hash}" if object.is_a? Parfait::Type
      return unless add_object( object )
      # probably should make labels or even instructions derive from Parfait::Object, but . .
      if object.is_a? Register::Label
        object.each_label { |l| self.add_object(l)}
      end
      return unless object.respond_to? :has_type?
      type = object.get_type
      keep(type  , depth + 1)
      return if object.is_a? Symbol
      type.names.each do |name|
        #puts "Keep #{name} for #{object.class}"
        inst = object.get_instance_variable name
        keep(inst , depth + 1)
      end
      if object.is_a? Parfait::List
        object.each do |item|
          #puts "Keep item "
          keep(item , depth + 1)
        end
      end
    end
  end
end