Module Core_kernel.Fdeque

A simple polymorphic functional double-ended queue. Use this if you need a queue-like data structure that provides enqueue and dequeue accessors on both ends. For strictly first-in, first-out access, see Fqueue.

Amortized running times assume that enqueue/dequeue are used sequentially, threading the changing deque through the calls.

type 'a t
include sig ... end
val bin_read_t : 'a Bin_prot.Read.reader ‑> 'a t Bin_prot.Read.reader
val __bin_read_t__ : 'a Bin_prot.Read.reader ‑> (Core_kernel__.Import.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
val bin_shape_t : Bin_prot.Shape.t ‑> Bin_prot.Shape.t
val compare : ('a ‑> 'a ‑> Core_kernel__.Import.int) ‑> 'a t ‑> 'a t ‑> Core_kernel__.Import.int
val hash_fold_t : (Base.Hash.state ‑> 'a ‑> Base.Hash.state) ‑> Base.Hash.state ‑> 'a t ‑> Base.Hash.state
val t_of_sexp : (Base.Sexp.t ‑> 'a) ‑> Base.Sexp.t ‑> 'a t
val sexp_of_t : ('a ‑> Base.Sexp.t) ‑> 'a t ‑> Base.Sexp.t

Container operations traverse deque elements front-to-back, like Front_to_back below. If you need faster traversal and don't care about the order, use Arbitrary_order below.

is_empty and length have worst-case complexity O(1).

include Container.S1 with type a t := a t
type 'a t
val mem : 'a t ‑> 'a ‑> equal:('a ‑> 'a ‑> bool) ‑> bool

Checks whether the provided element is there, using equal.

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 fold_result : 'a t ‑> init:'accum ‑> f:('accum ‑> 'a ‑> ('accum, 'e) Base.Result.t) ‑> ('accum, '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.

val fold_until : 'a t ‑> init:'accum ‑> f:('accum ‑> 'a ‑> ('accum, 'final) Base__.Container_intf.Continue_or_stop.t) ‑> finish:('accum ‑> '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.

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 Base.Commutative_group.S with type t = 'sum) ‑> 'a t ‑> f:('a ‑> 'sum) ‑> 'sum

Returns the sum of f i for all 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 ‑> 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.

val max_elt : 'a t ‑> compare:('a ‑> 'a ‑> int) ‑> 'a option
include Core_kernel__.Import.Invariant.S1 with type a t := a t
type 'a t
include Core_kernel__.Import.Monad.S with type a t := a t
type 'a t
include Base__.Monad_intf.S_without_syntax with type a t := a t
type 'a t
include Base__.Monad_intf.Infix with type a t := a t
type 'a t
val (>>=) : 'a t ‑> ('a ‑> 'b t) ‑> 'b t

t >>= f returns a computation that sequences the computations represented by two monad elements. The resulting computation first does t to yield a value v, and then runs the computation returned by f v.

val (>>|) : 'a t ‑> ('a ‑> 'b) ‑> 'b t

t >>| f is t >>= (fun a -> return (f a)).

module Monad_infix : Base__.Monad_intf.Infix with type a t := a t
val bind : 'a t ‑> f:('a ‑> 'b t) ‑> 'b t

bind t ~f = t >>= f

val return : 'a ‑> 'a t

return v returns the (trivial) computation that returns v.

val map : 'a t ‑> f:('a ‑> 'b) ‑> 'b t

map t ~f is t >>| f.

val join : 'a t t ‑> 'a t

join t is t >>= (fun t' -> t').

val ignore_m : 'a t ‑> unit t

ignore_m t is map t ~f:(fun _ -> ()). ignore_m used to be called ignore, but we decided that was a bad name, because it shadowed the widely used Pervasives.ignore. Some monads still do let ignore = ignore_m for historical reasons.

val all : 'a t list ‑> 'a list t
val all_unit : unit t list ‑> unit t
val all_ignore : unit t list ‑> unit t
  • Deprecated [since 2018-02] Use [all_unit]
include Base__.Monad_intf.Syntax with type a t := a t
type 'a t
module Let_syntax : sig ... end
module Arbitrary_order : sig ... end

Traverse deque elements in arbitrary order.

module Front_to_back : sig ... end

Traverse deque elements front-to-back. Incurs up to O(n) additional time and space cost over Arbitrary_order.

module Back_to_front : sig ... end

Traverse deque elements back-to-front. Incurs up to O(n) additional time and space cost over Arbitrary_order.

val empty : _ t

The empty deque.

val singleton : 'a ‑> 'a t

A one-element deque.

val of_list : 'a Core_kernel__.Import.list ‑> 'a t

of_list returns a deque with elements in the same front-to-back order as the list.

val rev : 'a t ‑> 'a t

rev t returns t, reversed.

Complexity: worst-case O(1).

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

enqueue t side x produces t updated with x added to its side.

Complexity: worst-case O(1).

val enqueue_front : 'a t ‑> 'a ‑> 'a t
val enqueue_back : 'a t ‑> 'a ‑> 'a t
val peek : 'a t ‑> [ `back | `front ] ‑> 'a Core_kernel__.Import.option

peek t side produces Some of the element at the side of t, or None if t is empty.

Complexity: worst-case O(1).

val peek_exn : 'a t ‑> [ `back | `front ] ‑> 'a
val peek_front : 'a t ‑> 'a Core_kernel__.Import.option
val peek_front_exn : 'a t ‑> 'a
val peek_back : 'a t ‑> 'a Core_kernel__.Import.option
val peek_back_exn : 'a t ‑> 'a
val drop : 'a t ‑> [ `back | `front ] ‑> 'a t Core_kernel__.Import.option

drop t side produces Some of t with the element at its side removed, or None if t is empty.

Complexity: amortized O(1), worst-case O(length t).

val drop_exn : 'a t ‑> [ `back | `front ] ‑> 'a t
val drop_front : 'a t ‑> 'a t Core_kernel__.Import.option
val drop_front_exn : 'a t ‑> 'a t
val drop_back : 'a t ‑> 'a t Core_kernel__.Import.option
val drop_back_exn : 'a t ‑> 'a t
val dequeue : 'a t ‑> [ `back | `front ] ‑> ('a * 'a t) Core_kernel__.Import.option

dequeue t side produces Option.both (peek t side) (drop t side).

Complexity: amortized O(1), worst-case O(length t).

val dequeue_exn : 'a t ‑> [ `back | `front ] ‑> 'a * 'a t
val dequeue_front : 'a t ‑> ('a * 'a t) Core_kernel__.Import.option
val dequeue_front_exn : 'a t ‑> 'a * 'a t
val dequeue_back : 'a t ‑> ('a * 'a t) Core_kernel__.Import.option
val dequeue_back_exn : 'a t ‑> 'a * 'a t
module Stable : sig ... end