Accessors name conflict trying to create a binding

Question

I'm trying to create a binding for an existing javascript library but I'm getting an error when I try to use the property access function.

[@bs.deriving abstract]
type objA = {
  prop1: string,
  prop2: string,
  prop3: string,
};

[@bs.deriving abstract]
type objB = {
  prop2: string,
  prop4: string,
};

[@bs.module "myLib"] external getObjA: (unit) => objA = "";
[@bs.module "myLib"] external getObjB: (unit) => objB = "";

let obj = getObjA();
prop2Get(obj) |> Js.log
// ------^^^
// Error: This expression has type objA but an expression was expected of type objB

I know that both objects have the same property name, so the generated function prop2Get(...) is being overridden. What is the solution for this case?

Answer 1

You need to namespace them. In OCaml/Reason the method of namespacing is to put them in separate modules. Specifically,

module ObjA = {
  [@bs.deriving abstract] type t = {
    prop1: string,
    prop2: string,
    prop3: string,
  };

  [@bs.module "myLib"] external get: (unit) => t = "getObjA";
};

module ObjB = {
  [@bs.deriving abstract] type t = {
    prop2: string,
    prop4: string,
  };

  [@bs.module "myLib"] external get: (unit) => t = "getObjB";
};

Now, the accessors are also namespaced by their type's module:

() |> ObjA.get |> ObjA.prop2Get |> Js.log;

The nice thing is that since the module name is used as part of the overall name, you don't need to repeat things in the names, like getObjA, getObjB.