signature BIN_IO =
sig
type instream
type outstream
val input1 : instream -> Word8.word option
val output1 : outstream -> Word8.word -> unit
val flushOut : outstream -> unit
val openIn : string -> instream
val closeIn : instream -> unit
val openOut : string -> outstream
val openAppend : string -> outstream
val closeOut : outstream -> unit
end
structure BinIO : BIN_IO