signature STREAM_IO =
sig
  type elem
  type instream
  type out_pos
  type outstream
  type pos
  type reader
  type vector
  type writer
  val canInput : instream * int -> int option
  val closeIn : instream -> unit
  val closeOut : outstream -> unit
  val endOfStream : instream -> bool
  val filePosIn : instream -> pos
  val filePosOut : out_pos -> pos
  val flushOut : outstream -> unit
  val getBufferMode : outstream -> IO.buffer_mode
  val getPosOut : outstream -> out_pos
  val getReader : instream -> reader * vector
  val getWriter : outstream -> writer * IO.buffer_mode
  val input : instream -> vector * instream
  val input1 : instream -> (elem * instream) option
  val inputAll : instream -> vector * instream
  val inputN : instream * int -> vector * instream
  val mkInstream : reader * vector -> instream
  val mkOutstream : writer * IO.buffer_mode -> outstream
  val output : outstream * vector -> unit
  val output1 : outstream * elem -> unit
  val setBufferMode : outstream * IO.buffer_mode -> unit
  val setPosOut : out_pos -> outstream
end