Module Core.DequeSource

A double-ended queue that can shrink and expand on both ends.

An index is assigned to an element when it enters the queue, and the index of an element is static (i.e., an index refers to a distinct element until that element is removed from the queue, no matter how many intervening push/pop operations occur).

One consequence of this is that the minimum index may be less than zero.

The "front" is the smallest valid index, while the "back" is the largest.

All operations are amortized O(1) with a small constant.

Sourcetype 'a t
include Bin_prot.Binable.S1 with type 'a t := 'a t
Sourceval bin_size_t : ('a, 'a t) Bin_prot.Size.sizer1
Sourceval bin_write_t : ('a, 'a t) Bin_prot.Write.writer1
Sourceval bin_read_t : ('a, 'a t) Bin_prot.Read.reader1
Sourceval __bin_read_t__ : ('a, int -> 'a t) Bin_prot.Read.reader1
Sourceval bin_writer_t : ('a, 'a t) Bin_prot.Type_class.S1.writer
Sourceval bin_reader_t : ('a, 'a t) Bin_prot.Type_class.S1.reader
Sourceval bin_t : ('a, 'a t) Bin_prot.Type_class.S1.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 Binary_searchable.S1 with type 'a t := 'a t
Sourceval binary_search_segmented : ?pos:int -> ?len:int -> 'a t -> segment_of:('a -> [ `Left | `Right ]) -> [ `Last_on_left | `First_on_right ] -> int option
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) Base.Result.t) -> ('acc, 'e) Base.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) Base.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.

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

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

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
Sourceval create : ?initial_length:Base.Int.t -> ?never_shrink:Base.Bool.t -> Base.Unit.t -> _ t

create ?initial_length ?never_shrink () creates a new t. initial_length is the initial length of the dequeue; it will be able to hold initial_length elements without resizing. It must be positive. If never_shrink is true, the physical array will never shrink, only expand. If initial_length is given without never_shrink, then never_shrink is presumed to be true, otherwise never_shrink defaults to false.

  • parameter initial_length

    defaults to 7

Sourceval of_array : 'a Base.Array.t -> 'a t

of_array arr creates a dequeue containing the elements of arr. The first element of the array will be at the front of the dequeue.

Sourceval front_index : _ t -> Base.Int.t Base.Option.t

front_index t return the index of the front item in t.

Sourceval front_index_exn : _ t -> Base.Int.t

front_index_exn t throws an exception if t is empty, otherwise returns the index of the front item in t.

Sourceval back_index : _ t -> Base.Int.t Base.Option.t

back_index t return the index of the back item in t.

Sourceval back_index_exn : _ t -> Base.Int.t

back_index_exn t throws an exception if t is empty, otherwise returns the index of the back item in t.

Sourceval get_opt : 'a t -> Base.Int.t -> 'a Base.Option.t

get_opt t i returns the element at index i. Return None if i is invalid.

Sourceval get : 'a t -> Base.Int.t -> 'a

get t i returns the element at index i. Raise an exception if i is invalid.

Sourceval peek : 'a t -> [ `back | `front ] -> 'a Base.Option.t

peek t back_or_front returns the value at the back or front of the dequeue without removing it.

Sourceval peek_front : 'a t -> 'a Base.Option.t
Sourceval peek_front_exn : 'a t -> 'a
Sourceval peek_back : 'a t -> 'a Base.Option.t
Sourceval peek_back_exn : 'a t -> 'a
Sourceval set_exn : 'a t -> Base.Int.t -> 'a -> Base.Unit.t

set_exn t i v mutates the element at i.

Sourceval iter' : 'a t -> [ `front_to_back | `back_to_front ] -> f:('a -> Base.Unit.t) -> Base.Unit.t

iter' t ~f iterates over the elements of t.

Sourceval iteri : 'a t -> f:(Base.Int.t -> 'a -> Base.Unit.t) -> Base.Unit.t

iteri t ~f iterates over the elements of t `front_to_back passing in the index.

Sourceval iteri' : 'a t -> [ `front_to_back | `back_to_front ] -> f:(Base.Int.t -> 'a -> Base.Unit.t) -> Base.Unit.t

iteri' t ~f is the same as iter', but also passes in the index of the current element.

Sourceval fold' : 'a t -> [ `front_to_back | `back_to_front ] -> init:'b -> f:('b -> 'a -> 'b) -> 'b

fold' t ~init ~f folds over the elements of t.

Sourceval foldi : 'a t -> init:'b -> f:(Base.Int.t -> 'b -> 'a -> 'b) -> 'b

foldi t ~init ~f is the same as fold, but also passes in the index of the current element to f.

Sourceval foldi' : 'a t -> [ `front_to_back | `back_to_front ] -> init:'b -> f:(Base.Int.t -> 'b -> 'a -> 'b) -> 'b

foldi' t ~init ~f is the same as fold', but also passes in the index of the current element to f.

Sourceval enqueue : 'a t -> [ `back | `front ] -> 'a -> Base.Unit.t

enqueue t back_or_front v pushes v onto the back_or_front of t.

Sourceval enqueue_front : 'a t -> 'a -> Base.Unit.t
Sourceval enqueue_back : 'a t -> 'a -> Base.Unit.t
Sourceval clear : _ t -> Base.Unit.t

clear t removes all elements from t.

Sourceval drop : ?n:Base.Int.t -> _ t -> [ `back | `front ] -> Base.Unit.t

drop ?n t back_or_front drops n elements (default 1) from the back_or_front of t. If t has fewer than n elements then it is cleared.

Sourceval drop_front : ?n:Base.Int.t -> _ t -> Base.Unit.t
Sourceval drop_back : ?n:Base.Int.t -> _ t -> Base.Unit.t
Sourceval dequeue : 'a t -> [ `back | `front ] -> 'a Base.Option.t

dequeue t back_or_front removes and returns the back_or_front of t.

Sourceval dequeue_exn : 'a t -> [ `back | `front ] -> 'a
Sourceval dequeue_front : 'a t -> 'a Base.Option.t
Sourceval dequeue_front_exn : 'a t -> 'a
Sourceval dequeue_back : 'a t -> 'a Base.Option.t
Sourceval dequeue_back_exn : 'a t -> 'a