MLton 20210117

# MLtonIO

    signature MLTON_IO =
       sig
          type instream
          type outstream

          val inFd: instream -> Posix.IO.file_desc
          val mkstemp: string -> string * outstream
          val mkstemps: {prefix: string, suffix: string} -> string * outstream
          val newIn: Posix.IO.file_desc * string -> instream
          val newOut: Posix.IO.file_desc * string -> outstream
          val outFd: outstream -> Posix.IO.file_desc
          val tempPrefix: string -> string
       end

- inFd ins

  returns the file descriptor corresponding to ins.

- mkstemp s

  like the C mkstemp function, generates and open a temporary file with prefix s.

- mkstemps {prefix, suffix}

  like mkstemp, except it has both a prefix and suffix.

- newIn (fd, name)

  creates a new instream from file descriptor fd, with name used in any Io exceptions later raised.

- newOut (fd, name)

  creates a new outstream from file descriptor fd, with name used in any Io exceptions later raised.

- outFd out

  returns the file descriptor corresponding to out.

- tempPrefix s

  adds a suitable system or user specific prefix (directory) for temp files.