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js-of-ocamlocsigen

Wrap an OCaml function that returns a record

I have defined an OCaml function manipulate: string -> string. And I wrap it to make a JS function jsManipulate: 

let () =
  Js.Unsafe.global##.jsManipulate := Js.wrap_callback
      (fun s -> Js.string (manipulate (Js.to_string s)))

Now, I want to make manipulate return more information than just a string; I want it to return a record: manipulate: string -> myrecord where myrecord = { result: string; info_1: int; info_2: bool } in OCaml format.

In this case, does anyone know how to wrap manipulate to make a JS function that returns also a JS record (or object?) from a JS string?

PS: I want to call manipulate only one time (rather than 3 times) to build the JS object.

Solution

  • Regular javascript is not going to be able to understand OCaml's record, even when code is compiled in javascript with js_of_ocaml.

    What you should use instead is a javascript object (There is no difference between a record and an object in javascript). You can read about creating literal objects at the bottom of this page: http://ocsigen.org/js_of_ocaml/2.7/api/Ppx_js

    You can create a function to_object of type myrecord -> < .. > Js.t that returns an object. Then you can use it for wrapping instead of Js.to_string.