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(*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*)
(** IArray - Immutable view of an array *)
open Import0
include (
Array.Permissioned :
module type of Array.Permissioned
with type ('a, 'p) t := ('a, 'p) Array.Permissioned.t )
type 'a t = ('a, immutable) Array.Permissioned.t
let a2i (a : 'a array) : 'a t = Obj.magic a
let i2a (a : 'a t) : 'a array = Obj.magic a
let compare compare_elt = compare compare_elt compare_immutable
let hash_fold_t hash_fold_elt s (a : _ t) =
Hash.Builtin.hash_fold_array_frozen hash_fold_elt s (i2a a)
let t_of_sexp elt_of_sexp = t_of_sexp elt_of_sexp immutable_of_sexp
let sexp_of_t sexp_of_elt = sexp_of_t sexp_of_elt sexp_of_immutable
module Import = struct
type 'a iarray = 'a t [@@deriving compare, equal, hash, sexp]
end
let pp sep pp_elt fs a = List.pp sep pp_elt fs (to_list a)
let empty = Obj.magic [||]
let of_ x = create ~len:1 x
let of_array = a2i
let contains_dup ~compare xs =
let equal x y = compare x y = 0 in
Option.is_some
(find_consecutive_duplicate ~equal (sorted_copy ~compare xs))
let fold_map xs ~init ~f =
Tuple2.map_snd ~f:a2i (Array.fold_map (i2a xs) ~init ~f)
let fold_map_until xs ~init ~f ~finish =
with_return (fun {return} ->
finish
(fold_map xs ~init ~f:(fun s x ->
match (f s x : _ Continue_or_stop.t) with
| Continue x -> x
| Stop x -> return x )) )
let map_preserving_phys_equal xs ~f =
let change = ref false in
let xs' =
map xs ~f:(fun x ->
let x' = f x in
if not (x' == x) then change := true ;
x' )
in
if !change then xs' else xs
let combine_adjacent ~f xs =
let xs = i2a xs in
let n = Array.length xs - 1 in
let rec combine_adjacent_ j i xs =
if i < n then (
match f xs.(i - j) xs.(i + 1) with
| None ->
if j != 0 then xs.(i + 1 - j) <- xs.(i + 1) ;
combine_adjacent_ j (i + 1) xs
| Some x ->
let xs = if j = 0 then Array.copy xs else xs in
xs.(i - j) <- x ;
combine_adjacent_ (j + 1) (i + 1) xs )
else if j = 0 then xs
else Array.sub xs ~pos:0 ~len:(n + 1 - j)
in
a2i (combine_adjacent_ 0 0 xs)