Module Batteries.Deque

module Deque: BatDeque

type +'a dq

The type of double-ended queues

type 'a t = 'a dq

A synonym for convenience

include BatEnum.Enumerable

include BatInterfaces.Mappable

val size : 'a dq -> int

size dq is the number of elements in the dq. O(1)

Construction

val empty : 'a dq

The empty deque.

val cons : 'a -> 'a dq -> 'a dq

cons x dq adds x to the front of dq. O(1)

val snoc : 'a dq -> 'a -> 'a dq

snoc x dq adds x to the rear of dq. O(1)

Deconstruction

val front : 'a dq -> ('a * 'a dq) option

front dq returns Some (x, dq') iff x is at the front of dq and dq' is the rest of dq excluding x, and None if dq has no elements. O(1) amortized, O(n) worst case

val rear : 'a dq -> ('a dq * 'a) option

rear dq returns Some (dq', x) iff x is at the rear of dq and dq' is the rest of dq excluding x, and None if dq has no elements. O(1) amortized, O(n) worst case

Basic operations

val eq : ?eq:('a -> 'a -> bool) -> 'a dq -> 'a dq -> bool

eq dq1 dq2 is true if dq1 and dq2 have the same sequence of elements. A custom function can be optionally provided with the eq parameter (default is Pervasives.(=)).

Since 2.2.0

val rev : 'a dq -> 'a dq

rev dq reverses dq. O(1)

val is_empty : 'a dq -> bool

is_empty dq returns true iff dq has no elements. O(1)

val at : ?backwards:bool -> 'a dq -> int -> 'a option

at ~backwards dq k returns the kth element of dq, from the front if backwards is false, and from the rear if backwards is true. By default, backwards = false. O(n)

val map : ('a -> 'b) -> 'a dq -> 'b dq

map f dq returns a deque where every element x of dq has been replaced with f x. O(n)

val mapi : (int -> 'a -> 'b) -> 'a dq -> 'b dq

mapi f dq returns a deque where every element x of dq has been replaced with f n x, where n is the position of x from the front of dq. O(n)

val iter : ('a -> unit) -> 'a dq -> unit

iter f dq calls f x on each element x of dq. O(n)

val iteri : (int -> 'a -> unit) -> 'a dq -> unit

iteri f dq calls f n x on each element x of dq. The first argument to f is the position of the element from the front of dq. O(n)

val find : ?backwards:bool -> ('a -> bool) -> 'a dq -> (int * 'a) option

find ~backwards f dq returns Some (n, x) if x at position n is such that f x is true, or None if there is no such element. The position n is from the rear if backwards is true, and from the front if backwards is false. By default, backwards is false. O(n)

val fold_left : ('acc -> 'a -> 'acc) -> 'acc -> 'a dq -> 'acc

fold_left f acc dq is equivalent to List.fold_left f acc (to_list dq), but more efficient. O(n)

val fold_right : ('a -> 'acc -> 'acc) -> 'a dq -> 'acc -> 'acc

fold_right f dq acc is equivalent to List.fold_right f (to_list dq) acc, but more efficient. O(n)

val append : 'a dq -> 'a dq -> 'a dq

append dq1 dq2 represents the concatenateion of dq1 and dq2. O(min(m, n))

val append_list : 'a dq -> 'a list -> 'a dq

append_list dq l is equivalent to append dq (of_list l), but more efficient. O(min(m, n))

val prepend_list : 'a list -> 'a dq -> 'a dq

prepend_list l dq is equivalent to append (of_list l) dq, but more efficient. O(min(m, n))

val rotate_forward : 'a dq -> 'a dq

A cyclic shift of deque elements from rear to front by one position. As a result, the front element becomes the rear element. Time: O(1) amortized, O(n) worst-case.

Since 2.3.0

val rotate_backward : 'a dq -> 'a dq

A cyclic shift of deque elements from front to rear by one position. As a result, the rear element becomes the front element. Time: O(1) amortized, O(n) worst-case.

Since 2.3.0

Transformation

val of_list : 'a list -> 'a dq

of_list l is a deque representation of the elements of l. O(n)

val to_list : 'a dq -> 'a list

to_list dq is a list representation of the elements of dq. O(n)

val of_enum : 'a BatEnum.t -> 'a dq

of_enum e is a deque representation of the elements of e. Consumes the enumeration e. O(n)

val enum : 'a dq -> 'a BatEnum.t

enum dq is an enumeration of the elements of dq from the front to the rear. This function is O(1), but generating each element of the enumeration is amortized O(1), and O(n) worst case.

Printing

val print : ?first:string ->
       ?last:string ->
       ?sep:string -> ('a, 'b) BatIO.printer -> ('a dq, 'b) BatIO.printer

Print the contents of the deque. O(n)