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Module Deque

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 < 0.

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

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

Signature

type 'a t
val t_of_sexp : (Sexplib.Sexp.t -> 'a) -> Sexplib.Sexp.t -> 'a t
val sexp_of_t : ('a -> Sexplib.Sexp.t) -> 'a t -> Sexplib.Sexp.t
val bin_read_t : 'a Bin_prot.Read.reader -> 'a t Bin_prot.Read.reader
val __bin_read_t__ : 'a Bin_prot.Read.reader -> (int -> 'a t) Bin_prot.Read.reader
val bin_size_t : 'a Bin_prot.Size.sizer -> 'a t Bin_prot.Size.sizer
val bin_write_t : 'a Bin_prot.Write.writer -> 'a t Bin_prot.Write.writer
include Binary_searchable.S1 with type 'a t := 'a t
type 'a t
val binary_search : ('a t, 'a) Binary_searchable_intf.binary_search
val binary_search_segmented : ('a t, 'a) Binary_searchable_intf.binary_search_segmented
include Container.S1 with type 'a t := 'a t
type 'a t
val mem : ?equal:('a -> 'a -> bool) -> 'a t -> 'a -> bool

Checks whether the provided element is there, using polymorphic compare if equal is not provided

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

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

val 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.

val 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.

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

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

val sum : (module Commutative_group.S with type t = 'sum) -> 'a t -> f:('a -> 'sum) -> 'sum

Returns the sum of f i for i in the container

val find : 'a t -> f:('a -> bool) -> 'a option

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

val 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.

val to_list : 'a t -> 'a list
val to_array : 'a t -> 'a array
val min_elt : 'a t -> cmp:('a -> 'a -> int) -> 'a option

Returns a minimum (resp maximum) element from the collection using the provided cmp 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.

val max_elt : 'a t -> cmp:('a -> 'a -> int) -> 'a option
val create : ?initial_length:int -> ?never_shrink:bool -> unit -> _ t

create ?initial_length ?never_shrink () create 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.

val front_index : _ t -> int option

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

val front_index_exn : _ t -> int

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

val back_index : _ t -> int option

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

val back_index_exn : _ t -> int

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

val get_opt : 'a t -> int -> 'a option

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

val get : 'a t -> int -> 'a

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

val peek : 'a t -> [
| `back
| `front
] -> 'a option

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

val peek_front : 'a t -> 'a option
val peek_front_exn : 'a t -> 'a
val peek_back : 'a t -> 'a option
val peek_back_exn : 'a t -> 'a
val set_exn : 'a t -> int -> 'a -> unit

set_exn t i v mutate the element at i.

val iter' : 'a t -> [
| `front_to_back
| `back_to_front
] -> f:('a -> unit) -> unit

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

val iteri : 'a t -> f:(int -> 'a -> unit) -> unit

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

val iteri' : 'a t -> [
| `front_to_back
| `back_to_front
] -> f:(int -> 'a -> unit) -> unit

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

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

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

val foldi : 'a t -> init:'b -> f:(int -> 'b -> 'a -> 'b) -> 'b

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

val foldi' : 'a t -> [
| `front_to_back
| `back_to_front
] -> init:'b -> f:(int -> 'b -> 'a -> 'b) -> 'b

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

val enqueue : 'a t -> [
| `back
| `front
] -> 'a -> unit

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

val enqueue_front : 'a t -> 'a -> unit
val enqueue_back : 'a t -> 'a -> unit
val clear : _ t -> unit

clear t removes all elements from t.

val drop : ?n:int -> _ t -> [
| `back
| `front
] -> unit

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

val drop_front : ?n:int -> _ t -> unit
val drop_back : ?n:int -> _ t -> unit
val dequeue : 'a t -> [
| `back
| `front
] -> 'a option

dequeue t back_or_front remove and return the back_or_front of t

val dequeue_exn : 'a t -> [
| `back
| `front
] -> 'a
val dequeue_front : 'a t -> 'a option
val dequeue_front_exn : 'a t -> 'a
val dequeue_back : 'a t -> 'a option
val dequeue_back_exn : 'a t -> 'a