Module Base.Linked_queueSource

This module is a Base-style wrapper around OCaml's standard Queue module.

Sourcetype 'a t = 'a Queue.t
include Sexplib0.Sexpable.S1 with type 'a t := 'a t
Sourceval t_of_sexp : (Sexplib0.Sexp.t -> 'a) -> Sexplib0.Sexp.t -> 'a t
Sourceval sexp_of_t : ('a -> Sexplib0.Sexp.t) -> 'a t -> Sexplib0.Sexp.t
include Indexed_container.S1 with type 'a t := 'a t
include Container.S1 with type 'a t := 'a t
Sourceval mem : 'a t -> 'a -> equal:('a -> 'a -> bool) -> bool

Checks whether the provided element is there, using equal.

Sourceval length : 'a t -> int
Sourceval is_empty : 'a t -> bool
Sourceval iter : 'a t -> f:('a -> unit) -> unit
Sourceval fold : 'a t -> init:'acc -> f:('acc -> 'a -> 'acc) -> 'acc

fold t ~init ~f returns f (... f (f (f init e1) e2) e3 ...) en, where e1..en are the elements of t

Sourceval fold_result : 'a t -> init:'acc -> f:('acc -> 'a -> ('acc, 'e) Result.t) -> ('acc, 'e) Result.t

fold_result t ~init ~f is a short-circuiting version of fold that runs in the Result monad. If f returns an Error _, that value is returned without any additional invocations of f.

Sourceval fold_until : 'a t -> init:'acc -> f:('acc -> 'a -> ('acc, 'final) Container.Continue_or_stop.t) -> finish:('acc -> 'final) -> 'final

fold_until t ~init ~f ~finish is a short-circuiting version of fold. If f returns Stop _ the computation ceases and results in that value. If f returns Continue _, the fold will proceed. If f never returns Stop _, the final result is computed by finish.

Example:

  type maybe_negative =
    | Found_negative of int
    | All_nonnegative of { sum : int }

  (** [first_neg_or_sum list] returns the first negative number in [list], if any,
      otherwise returns the sum of the list. *)
  let first_neg_or_sum =
    List.fold_until ~init:0
      ~f:(fun sum x ->
        if x < 0
        then Stop (Found_negative x)
        else Continue (sum + x))
      ~finish:(fun sum -> All_nonnegative { sum })
  ;;

  let x = first_neg_or_sum [1; 2; 3; 4; 5]
  val x : maybe_negative = All_nonnegative {sum = 15}

  let y = first_neg_or_sum [1; 2; -3; 4; 5]
  val y : maybe_negative = Found_negative -3
Sourceval exists : 'a t -> f:('a -> bool) -> bool

Returns true if and only if there exists an element for which the provided function evaluates to true. This is a short-circuiting operation.

Sourceval for_all : 'a t -> f:('a -> bool) -> bool

Returns true if and only if the provided function evaluates to true for all elements. This is a short-circuiting operation.

Sourceval count : 'a t -> f:('a -> bool) -> int

Returns the number of elements for which the provided function evaluates to true.

Returns the sum of f i for all i in the container.

Sourceval sum : (module Container.Summable with type t = 'sum) -> 'a t -> f:('a -> 'sum) -> 'sum
Sourceval find : 'a t -> f:('a -> bool) -> 'a option

Returns as an option the first element for which f evaluates to true.

Sourceval find_map : 'a t -> f:('a -> 'b option) -> 'b option

Returns the first evaluation of f that returns Some, and returns None if there is no such element.

Sourceval to_list : 'a t -> 'a list
Sourceval to_array : 'a t -> 'a array
Sourceval min_elt : 'a t -> compare:('a -> 'a -> int) -> 'a option

Returns a minimum (resp maximum) element from the collection using the provided compare function, or None if the collection is empty. In case of a tie, the first element encountered while traversing the collection is returned. The implementation uses fold so it has the same complexity as fold.

Sourceval max_elt : 'a t -> compare:('a -> 'a -> int) -> 'a option

These are all like their equivalents in Container except that an index starting at 0 is added as the first argument to f.

Sourceval foldi : 'a t -> init:_ -> f:(int -> _ -> 'a -> _) -> _
Sourceval iteri : 'a t -> f:(int -> 'a -> unit) -> unit
Sourceval existsi : 'a t -> f:(int -> 'a -> bool) -> bool
Sourceval for_alli : 'a t -> f:(int -> 'a -> bool) -> bool
Sourceval counti : 'a t -> f:(int -> 'a -> bool) -> int
Sourceval findi : 'a t -> f:(int -> 'a -> bool) -> (int * 'a) option
Sourceval find_mapi : 'a t -> f:(int -> 'a -> 'b option) -> 'b option
Sourceval singleton : 'a -> 'a t

singleton a returns a queue with one element.

Sourceval of_list : 'a list -> 'a t

of_list list returns a queue t with the elements of list in the same order as the elements of list (i.e. the first element of t is the first element of the list).

Sourceval of_array : 'a array -> 'a t
Sourceval init : int -> f:(int -> 'a) -> 'a t

init n ~f is equivalent to of_list (List.init n ~f).

Sourceval enqueue : 'a t -> 'a -> unit

enqueue t a adds a to the end of t.

Sourceval enqueue_all : 'a t -> 'a list -> unit

enqueue_all t list adds all elements in list to t in order of list.

Sourceval dequeue : 'a t -> 'a option

dequeue t removes and returns the front element of t, if any.

Sourceval dequeue_exn : 'a t -> 'a
Sourceval dequeue_and_ignore_exn : 'a t -> unit

dequeue_and_ignore_exn t removes the front element of t, or raises if the queue is empty.

Sourceval drain : 'a t -> f:('a -> unit) -> while_:('a -> bool) -> unit

drain t ~f ~while_ repeatedly calls while_ on the head of t, and if it returns true then dequeues it and calls f on it. It stops when t is empty or while_ returns false. A common use case is tracking the sum of data in a recent time interval: t contains timestamped data, while_ checks for elements with an old timestamp, and f subtracts data from the sum.

Sourceval peek : 'a t -> 'a option

peek t returns but does not remove the front element of t, if any.

Sourceval peek_exn : 'a t -> 'a
Sourceval clear : _ t -> unit

clear t discards all elements from t.

Sourceval copy : 'a t -> 'a t

copy t returns a copy of t.

Sourceval map : 'a t -> f:('a -> 'b) -> 'b t
Sourceval mapi : 'a t -> f:(int -> 'a -> 'b) -> 'b t
Sourceval concat_map : 'a t -> f:('a -> 'b list) -> 'b t

Creates a new queue with elements equal to List.concat_map ~f (to_list t).

Sourceval concat_mapi : 'a t -> f:(int -> 'a -> 'b list) -> 'b t
Sourceval filter_map : 'a t -> f:('a -> 'b option) -> 'b t

filter_map creates a new queue with elements equal to List.filter_map ~f (to_list t).

Sourceval filter_mapi : 'a t -> f:(int -> 'a -> 'b option) -> 'b t
Sourceval filter : 'a t -> f:('a -> bool) -> 'a t

filter is like filter_map, except with List.filter.

Sourceval filteri : 'a t -> f:(int -> 'a -> bool) -> 'a t
Sourceval filter_inplace : 'a t -> f:('a -> bool) -> unit

filter_inplace t ~f removes all elements of t that don't satisfy f. If f raises, t is unchanged. This is inplace in that it modifies t; however, it uses space linear in the final length of t.

Sourceval filteri_inplace : 'a t -> f:(int -> 'a -> bool) -> unit
Sourceval create : unit -> _ t

create () returns an empty queue.

Sourceval transfer : src:'a t -> dst:'a t -> unit

transfer ~src ~dst adds all of the elements of src to the end of dst, then clears src. It is equivalent to the sequence:

  iter ~src ~f:(enqueue dst);
  clear src

but runs in constant time.