let r =
  Result.return(20)
  ->Result.map(x => x + 20)
  ->Result.flatMap(x => Result.return(x + 2))
  ->Result.getOrElse(-1);
Js.log2("Result: ", r);

let r =
  Belt.Result.Ok(x => x + 10)
  ->Result.ap(Result.return(20))
  ->Belt.Result.map(_, x => x + 10)
  ->Result.flatMap(x => Belt.Result.Ok(x + 2))
  ->Belt.Result.getWithDefault(_, -1);
Js.log2("Result: ", r);

  (Js.Promise.resolve(20) |> Js.Promise.then_(x => Result.Promise.return(x)))
  ->Result.Promise.flatMap(x => Result.return(x + 10))
  ->Result.Promise.map(x => x + 10)
  ->Result.Promise.andThen(x =>
       x + 2 |> Result.return |> Js.Promise.resolve
     )
  ->Result.Promise.unsafeResolve
  |> Js.Promise.then_(result => {
       Js.log2("Result: ", result);
       Js.Promise.resolve();
     })