(*
Copyright (c) 2013, Simon Cruanes
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(** {1 Splay trees} *)

(** See http://en.wikipedia.org/wiki/Splay_tree and
    Okasaki's "purely functional data structures" p46 *)

type ('a, 'b) t
  (** A functional splay tree *)

val empty : cmp:('a -> 'a -> bool) -> ('a, 'b) t
  (** Empty splay tree using the given comparison function *)

val is_empty : (_, _) t -> bool
  (** Check whether the tree is empty *)

val insert : ('a, 'b) t -> 'a -> 'b -> ('a, 'b) t
  (** Insert the pair (key -> value) in the tree *)

val replace : ('a, 'b) t -> 'a -> 'b -> ('a, 'b) t
  (** Insert the pair (key -> value) into the tree, replacing
      the previous binding (if any). It replaces at most one
      binding. *)

val remove : ('a, 'b) t -> 'a -> ('a, 'b) t
  (** Remove an element by its key, returns the splayed tree *)

val top : ('a, b') t -> 'a * 'b
  (** Returns the top value, or raise Not_found is empty *)

val min : ('a, 'b) t -> 'a * 'b * ('a, b') t
  (** Access minimum value *)

val find : ('a, 'b) t -> 'a -> 'b * ('a, 'b) t
  (** Find the value for the given key (or raise Not_found).
      It also returns the splayed tree *)

val size : (_, _) t -> int
  (** Number of elements (linear) *)

val iter : ('a -> 'b -> unit) -> ('a, 'b) t -> unit
  (** Iterate on elements *)