An interesting corner case is
```
open struct let map f x = f x end
let () = map (fun _ -> ()) 0
```
since OCaml let's us open anonymous modules. In this case, -dtypedtree
generates an unqualified names. So it would be rather easy to remove all
opens to of the named modules, since OCaml will generate fully qualified
names, e.g., `Texp_ident "Stdlib!.List.map"`, but for anonymous modules, it
would be harder to do.

On Wed, Apr 23, 2025 at 10:32 AM Francois Pottier <francois.pottier@inria.fr>
wrote:

>
> Hello,
>
> Le 23/04/2025 à 16:10, Kenichi Asai a écrit :
> > Would it be possible to transform an OCaml file to the one that does
> > not use open?
>
> I don't know whether it is possible/easy to do this today,
> but it would certainly interesting and useful to have such
> a tool.
>
> I note that the output that you expect cannot always be
> produced, due to name shadowing issues. For example if
> the program is
>
> open List
> module List = struct end
> let test = map (fun x -> x + 1) [1; 2; 3]
>
> then the best output that one can expect is
>
> let map = List.map
> module List = struct end
> let test = map (fun x -> x + 1) [1; 2; 3]
>
> That said (contradicting myself), one can actually obtain
> better output if one is careful to always use absolute paths.
> In this example one could write:
>
> module List = struct end
> let test = Stdlib.List.map (fun x -> x + 1) [1; 2; 3]
>
> which relies on the fact that the name "Stdlib" is not shadowed.
>
> As far as I know there is currently no syntax for absolute
> paths in OCaml (every path is relative, and every name can
> be shadowed). Maybe we should consider adding such a syntax?
>
> --
> François Pottier
> francois.pottier@inria.fr
> https://cambium.inria.fr/~fpottier/
>
>