sig
val compress : 'a Extlib.IO.output -> unit Extlib.IO.output
val open_out :
?mode:Extlib.File.open_out_flag list ->
?perm:Extlib.File.permission -> string -> unit Extlib.IO.output
val with_out : unit Extlib.IO.output -> (unit Extlib.IO.output -> 'a) -> 'a
end