Module Apt.Pref

module Pref: sig .. end
for details on the apt_preferences format : man apt_preferences

type pin_t = 
| Release of (string * string) list
| Origin of string
| Version of string
type package_t = 
| Package of string
| Star
type pin_priority_t = int 
type apt_preferences = {
   package : package_t;
   pin : pin_t;
   pin_priority : pin_priority_t;
}