module type S1 = sig .. end
type 'a t
val mem : ?equal:('a -> 'a -> bool) -> 'a t -> 'a -> bool
val length : 'a t -> int
val is_empty : 'a t -> bool
val iter : 'a t -> f:('a -> unit) -> unit
val fold : 'a t -> init:'accum -> f:('accum -> 'a -> 'accum) -> 'accum
val exists : 'a t -> f:('a -> bool) -> bool
val for_all : 'a t -> f:('a -> bool) -> bool
val count : 'a t -> f:('a -> bool) -> int
val find : 'a t -> f:('a -> bool) -> 'a option
val find_map : 'a t -> f:('a -> 'b option) -> 'b option
val to_list : 'a t -> 'a list
val to_array : 'a t -> 'a array