Exception
   NoMemoryError
   ScriptError
      NotImplementedError
      LoadError
      SyntaxError
   StandardError
      SystemStackError
      LocalJumpError
      IOError
         EOFError
      RegexpError
      ZeroDivisionError
      ThreadError
      SystemCallError
      SecurityError
      RuntimeError
      NameError
         NoMethodError
      RangeError
         FloatDomainError
      IndexError
      ArgumentError
      TypeError
   SignalException
      Interrupt
   SystemExit