Module Core_kernel.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 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.
include Bin_prot.Binable.S1 with type 'a t := 'a t
val bin_shape_t : Bin_prot.Shape.t -> Bin_prot.Shape.t
val bin_size_t : ('a, 'a t) Bin_prot.Size.sizer1
val bin_write_t : ('a, 'a t) Bin_prot.Write.writer1
val bin_read_t : ('a, 'a t) Bin_prot.Read.reader1
val __bin_read_t__ : ('a, int -> 'a t) Bin_prot.Read.reader1
val bin_writer_t : ('a, 'a t) Bin_prot.Type_class.S1.writer
val bin_reader_t : ('a, 'a t) Bin_prot.Type_class.S1.reader
val bin_t : ('a, 'a t) Bin_prot.Type_class.S1.t
include Ppx_sexp_conv_lib.Sexpable.S1 with type 'a t := 'a t
val t_of_sexp : (Sexplib0.Sexp.t -> 'a) -> Sexplib0.Sexp.t -> 'a t
val sexp_of_t : ('a -> Sexplib0.Sexp.t) -> 'a t -> Sexplib0.Sexp.t
include Binary_searchable.S1 with type 'a t := 'a t
val binary_search : ('a t, 'a, 'key) Base__.Binary_searchable_intf.binary_search
val binary_search_segmented : ('a t, 'a) Base__.Binary_searchable_intf.binary_search_segmented
include Container.S1 with type 'a t := '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
returnsf (... f (f (f init e1) e2) e3 ...) en
, wheree1..en
are the elements oft
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 offold
that runs in theResult
monad. Iff
returns anError _
, that value is returned without any additional invocations off
.
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 offold
. Iff
returnsStop _
the computation ceases and results in that value. Iff
returnsContinue _
, the fold will proceed. Iff
never returnsStop _
, the final result is computed byfinish
.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
val exists : 'a t -> f:('a -> bool) -> bool
Returns
true
if and only if there exists an element for which the provided function evaluates totrue
. 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 totrue
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__.Container_intf.Summable with type t = 'sum) -> 'a t -> f:('a -> 'sum) -> 'sum
Returns the sum of
f i
for alli
in the container.
val find : 'a t -> f:('a -> bool) -> 'a option
Returns as an
option
the first element for whichf
evaluates to true.
val find_map : 'a t -> f:('a -> 'b option) -> 'b option
Returns the first evaluation of
f
that returnsSome
, and returnsNone
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, orNone
if the collection is empty. In case of a tie, the first element encountered while traversing the collection is returned. The implementation usesfold
so it has the same complexity asfold
.
val max_elt : 'a t -> compare:('a -> 'a -> int) -> 'a option
val create : ?initial_length:Core_kernel__.Import.int -> ?never_shrink:Core_kernel__.Import.bool -> Core_kernel__.Import.unit -> _ t
create ?initial_length ?never_shrink ()
creates a newt
.initial_length
is the initial length of the dequeue; it will be able to holdinitial_length
elements without resizing. It must be positive. Ifnever_shrink
is true, the physical array will never shrink, only expand. Ifinitial_length
is given withoutnever_shrink
, thennever_shrink
is presumed to betrue
, otherwisenever_shrink
defaults tofalse
.- parameter initial_length
defaults to 7
val of_array : 'a Core_kernel__.Import.array -> 'a t
of_array arr
creates a dequeue containing the elements ofarr
. The first element of the array will be at the front of the dequeue.
val front_index : _ t -> Core_kernel__.Import.int Core_kernel__.Import.option
front_index t
return the index of the front item int
.
val front_index_exn : _ t -> Core_kernel__.Import.int
front_index_exn t
throws an exception ift
is empty, otherwise returns the index of the front item int
.
val back_index : _ t -> Core_kernel__.Import.int Core_kernel__.Import.option
back_index t
return the index of the back item int
.
val back_index_exn : _ t -> Core_kernel__.Import.int
back_index_exn t
throws an exception ift
is empty, otherwise returns the index of the back item int
.
val get_opt : 'a t -> Core_kernel__.Import.int -> 'a Core_kernel__.Import.option
get_opt t i
returns the element at indexi
. ReturnNone
ifi
is invalid.
val get : 'a t -> Core_kernel__.Import.int -> 'a
get t i
returns the element at indexi
. Raise an exception ifi
is invalid.
val peek : 'a t -> [ `back | `front ] -> 'a Core_kernel__.Import.option
peek t back_or_front
returns the value at the back or front of the dequeue without removing it.
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 set_exn : 'a t -> Core_kernel__.Import.int -> 'a -> Core_kernel__.Import.unit
set_exn t i v
mutates the element ati
.
val iter' : 'a t -> [ `front_to_back | `back_to_front ] -> f:('a -> Core_kernel__.Import.unit) -> Core_kernel__.Import.unit
iter' t ~f
iterates over the elements oft
.
val iteri : 'a t -> f:(Core_kernel__.Import.int -> 'a -> Core_kernel__.Import.unit) -> Core_kernel__.Import.unit
iteri t ~f
iterates over the elements oft
`front_to_back
passing in the index.
val iteri' : 'a t -> [ `front_to_back | `back_to_front ] -> f:(Core_kernel__.Import.int -> 'a -> Core_kernel__.Import.unit) -> Core_kernel__.Import.unit
iteri' t ~f
is the same asiter'
, 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
folds over the elements oft
.
val foldi : 'a t -> init:'b -> f:(Core_kernel__.Import.int -> 'b -> 'a -> 'b) -> 'b
foldi t ~init ~f
is the same asfold
, but also passes in the index of the current element tof
.
val foldi' : 'a t -> [ `front_to_back | `back_to_front ] -> init:'b -> f:(Core_kernel__.Import.int -> 'b -> 'a -> 'b) -> 'b
foldi' t ~init ~f
is the same asfold'
, but also passes in the index of the current element tof
.
val enqueue : 'a t -> [ `back | `front ] -> 'a -> Core_kernel__.Import.unit
enqueue t back_or_front v
pushesv
onto theback_or_front
oft
.
val enqueue_front : 'a t -> 'a -> Core_kernel__.Import.unit
val enqueue_back : 'a t -> 'a -> Core_kernel__.Import.unit
val clear : _ t -> Core_kernel__.Import.unit
clear t
removes all elements fromt
.
val drop : ?n:Core_kernel__.Import.int -> _ t -> [ `back | `front ] -> Core_kernel__.Import.unit
drop ?n t back_or_front
dropsn
elements (default 1) from theback_or_front
oft
. Ift
has fewer thann
elements then it is cleared.
val drop_front : ?n:Core_kernel__.Import.int -> _ t -> Core_kernel__.Import.unit
val drop_back : ?n:Core_kernel__.Import.int -> _ t -> Core_kernel__.Import.unit
val dequeue : 'a t -> [ `back | `front ] -> 'a Core_kernel__.Import.option
dequeue t back_or_front
removes and returns theback_or_front
oft
.
val dequeue_exn : 'a t -> [ `back | `front ] -> 'a
val dequeue_front : 'a t -> 'a Core_kernel__.Import.option
val dequeue_front_exn : 'a t -> 'a
val dequeue_back : 'a t -> 'a Core_kernel__.Import.option
val dequeue_back_exn : 'a t -> 'a