`sig
type 'a t = unit -> 'a Seq.node
and 'a node = Nil | Cons of 'a * 'a Seq.t
val is_empty : 'a Seq.t -> bool
val uncons : 'a Seq.t -> ('a * 'a Seq.t) option
val length : 'a Seq.t -> int
val iter : ('a -> unit) -> 'a Seq.t -> unit
val fold_left : ('a -> 'b -> 'a) -> 'a -> 'b Seq.t -> 'a
val iteri : (int -> 'a -> unit) -> 'a Seq.t -> unit
val fold_lefti : ('b -> int -> 'a -> 'b) -> 'b -> 'a Seq.t -> 'b
val for_all : ('a -> bool) -> 'a Seq.t -> bool
val exists : ('a -> bool) -> 'a Seq.t -> bool
val find : ('a -> bool) -> 'a Seq.t -> 'a option
val find_map : ('a -> 'b option) -> 'a Seq.t -> 'b option
val iter2 : ('a -> 'b -> unit) -> 'a Seq.t -> 'b Seq.t -> unit
val fold_left2 : ('a -> 'b -> 'c -> 'a) -> 'a -> 'b Seq.t -> 'c Seq.t -> 'a
val for_all2 : ('a -> 'b -> bool) -> 'a Seq.t -> 'b Seq.t -> bool
val exists2 : ('a -> 'b -> bool) -> 'a Seq.t -> 'b Seq.t -> bool
val equal : ('a -> 'b -> bool) -> 'a Seq.t -> 'b Seq.t -> bool
val compare : ('a -> 'b -> int) -> 'a Seq.t -> 'b Seq.t -> int
val empty : 'a Seq.t
val return : 'a -> 'a Seq.t
val cons : 'a -> 'a Seq.t -> 'a Seq.t
val init : int -> (int -> 'a) -> 'a Seq.t
val unfold : ('b -> ('a * 'b) option) -> 'b -> 'a Seq.t
val repeat : 'a -> 'a Seq.t
val forever : (unit -> 'a) -> 'a Seq.t
val cycle : 'a Seq.t -> 'a Seq.t
val iterate : ('a -> 'a) -> 'a -> 'a Seq.t
val map : ('a -> 'b) -> 'a Seq.t -> 'b Seq.t
val mapi : (int -> 'a -> 'b) -> 'a Seq.t -> 'b Seq.t
val filter : ('a -> bool) -> 'a Seq.t -> 'a Seq.t
val filter_map : ('a -> 'b option) -> 'a Seq.t -> 'b Seq.t
val scan : ('b -> 'a -> 'b) -> 'b -> 'a Seq.t -> 'b Seq.t
val take : int -> 'a Seq.t -> 'a Seq.t
val drop : int -> 'a Seq.t -> 'a Seq.t
val take_while : ('a -> bool) -> 'a Seq.t -> 'a Seq.t
val drop_while : ('a -> bool) -> 'a Seq.t -> 'a Seq.t
val group : ('a -> 'a -> bool) -> 'a Seq.t -> 'a Seq.t Seq.t
val memoize : 'a Seq.t -> 'a Seq.t
exception Forced_twice
val once : 'a Seq.t -> 'a Seq.t
val transpose : 'a Seq.t Seq.t -> 'a Seq.t Seq.t
val append : 'a Seq.t -> 'a Seq.t -> 'a Seq.t
val concat : 'a Seq.t Seq.t -> 'a Seq.t
val flat_map : ('a -> 'b Seq.t) -> 'a Seq.t -> 'b Seq.t
val concat_map : ('a -> 'b Seq.t) -> 'a Seq.t -> 'b Seq.t
val zip : 'a Seq.t -> 'b Seq.t -> ('a * 'b) Seq.t
val map2 : ('a -> 'b -> 'c) -> 'a Seq.t -> 'b Seq.t -> 'c Seq.t
val interleave : 'a Seq.t -> 'a Seq.t -> 'a Seq.t
val sorted_merge : ('a -> 'a -> int) -> 'a Seq.t -> 'a Seq.t -> 'a Seq.t
val product : 'a Seq.t -> 'b Seq.t -> ('a * 'b) Seq.t
val map_product : ('a -> 'b -> 'c) -> 'a Seq.t -> 'b Seq.t -> 'c Seq.t
val unzip : ('a * 'b) Seq.t -> 'a Seq.t * 'b Seq.t
val split : ('a * 'b) Seq.t -> 'a Seq.t * 'b Seq.t
val partition_map :
('a -> ('b, 'c) Stdlib.Either.t) -> 'a Seq.t -> 'b Seq.t * 'c Seq.t
val partition : ('a -> bool) -> 'a Seq.t -> 'a Seq.t * 'a Seq.t
val of_dispenser : (unit -> 'a option) -> 'a Seq.t
val to_dispenser : 'a Seq.t -> unit -> 'a option
val ints : int -> int Seq.t
end`