[MLton] MLton.TextIO.mkstemps

[Stephen Weeks]

> MLton.TextIO.mkstemps doesn't appear to be working well on
> x86-darwin
...
> Looks to me like both invocations of mlton ended up accessing the
> same file.

It does look that way.  Because MLton is deterministic, I would expect
both MLtons to try the same file, but one of them to get there first,
and the second to reject it.  Hmmm.  I tested the following program on
both platforms (using 20051202 on x86-darwin and HEAD on x86-linux).

  val (s, out) = MLton.TextIO.mkstemps {prefix = "/tmp/file", suffix = ""}
  val () = print (concat ["file is ", s, "\n"])
  val () = TextIO.output (out, "data\n")
  val () = TextIO.closeOut out

I observe the correct (and identical) behavior on both platforms.
Namely, each time the program runs, it creates a new file in /tmp,
after considering and rejecting each of the already created files
(observed via strace).  Note that MLton.TextIO.mkstemps is
deterministic because it uses MLton.Random, which is deterministic
unless MLton.Random.srand is called.

Do you get correct behavior with this program?