sig
type switch
val register :
LTerm_widget_callbacks.switch option -> 'a Lwt_sequence.t -> 'a -> unit
val stop : LTerm_widget_callbacks.switch -> unit
val exec_callbacks : ('a -> unit) Lwt_sequence.t -> 'a -> unit
val exec_filters : ('a -> bool) Lwt_sequence.t -> 'a -> bool
end