pref.sig

   1 signature PREF =
   2 sig
   3     val hasDirectory : int -> bool
   4     val setDirectory : int -> unit
   5     val unsetDirectory : int -> unit
   6
   7     val subscribed : string * string -> bool
   8     val subscribe : string * string -> bool
   9     val unsubscribe : string * string -> bool
  10 end