Array and list mapping question

[monstasat]

When mapping a JS array to OCaml array with gen_js_api, a new object is instantiated:

  let n = int_of_js (get objs "length") in
  Array.init (n - start) (fun i -> f (array_get objs (start + i)))

A new object is also created when mapping OCaml array to JS:

let array_make n = new_obj (get global "Array") [|int_to_js n|]

let array_to_js f arr =
  let n = Array.length arr in
  let a = array_make n in
  for i = 0 to n - 1 do
    array_set a i (f arr.(i))
  done;
  a

I want to map a JS object (which has fields of type 'array') to OCaml:

module Dataset : sig
   (* JS object *)
    type t
   
    val data : t -> float array
    val set_data : t -> float array -> unit

   (* Some other bindings here *)

    val make : ?data:float array ->
               (* Some other bindings here *)
               unit ->
               t [@@js.builder]

Javascript object t is used by an external JS library to render data on a chart. When the data array is mutated, the chart is re-rendered.
The problem here is that when I do such a mapping, a new data array is created, and all changes are made with a new object, not the original one. Original array stay untouched. Mutating this new array causes no re-render of a chart because it is not a part of t object. To force re-render, I should not only mutate the new array, but also set this new array to t object via set data function. This seems like a great overhead.
What is the best way to handle this problem?
Is there any way to make "direct" mapping between JS and OCaml arrays without new allocations?

[nojb]

Did you consider binding a function

val set: t -> int -> float -> unit
[@@js.implem let set a i x = Ojs.array_set (Ojs.get a "data") i (Ojs.float_to_js x)]

?

[monstasat]

I came to a similar solution. The only problem is that type t is not polymorphic, so I need to use a functor to use it with different types. Maybe the bindings can be implemented with 'a t type? Can this be done with gen_js_api? E.g. to have a 'set' function with the following interface:

val set: 'a t -> int -> 'a -> unit

?

[nojb]

A simple-minded approach is just to take Ojs.t arguments.