`sig type 'a t = 'a Stack.t exception Empty val create : unit -> 'a t val push : 'a -> 'a t -> unit val clear : 'a t -> unit val copy : 'a t -> 'a t val is_empty : 'a t -> bool val length : 'a t -> int val iter : ('a -> unit) -> 'a t -> unit type 'a enumerable = 'a t val enum : 'a t -> 'a BatEnum.t val enum_destruct : 'a t -> 'a BatEnum.t val of_enum : 'a BatEnum.t -> 'a t val print : ?first:string -> ?last:string -> ?sep:string -> ('a BatInnerIO.output -> 'b -> unit) -> 'a BatInnerIO.output -> 'b t -> unit val compare : 'a BatOrd.comp -> 'a t BatOrd.comp val equal : 'a BatOrd.eq -> 'a t BatOrd.eq module Exceptionless = BatStack.Exceptionless val top : 'a BatStack.t -> 'a option val pop : 'a BatStack.t -> 'a option end`