class RubyVM::InstructionSequence

def first_line
  self.to_a[4][:code_location][0]
end unless method_defined?(:first_line)

def last_line
  self.to_a[4][:code_location][2]
end unless method_defined?(:last_line)

def parameters_symbols
  ary = self.to_a
  argc = ary[4][:arg_size]
  locals = ary.to_a[10]
  locals[0...argc]
end unless method_defined?(:parameters_symbols)

def traceable_lines_norec lines
  code = self.to_a[13]
  line = 0
  code.each{|e|
    case e
    when Integer
      line = e
    when Symbol
      if /\ARUBY_EVENT_/ =~ e.to_s
        lines[line] = [e, *lines[line]]
      end
    end
  }
end

def traceable_lines_rec lines
  self.each_child{|ci| ci.traceable_lines_rec(lines)}
  traceable_lines_norec lines
end

def type
  self.to_a[9]
end unless method_defined?(:type)