Jump to definition: jumps to decl inside recursive modules

[trefis]

• /tmp/test.ml:

  module rec M : sig
    val f : unit -> unit
  end = struct
    let f () = ()
  end
  
  and N : sig
    val foo : unit -> unit
  end = struct
    let foo () = M.f ()
  end
  
  let foo () = M.f ()

• tests:

$ ocamlmerlin single locate -position 10:18 -look-for implementation -filename test.ml < /tmp/test.ml | jq .value
{
  "file": "test.ml",
  "pos": {
    "line": 2,
    "col": 6
  }
}
$ ocamlmerlin single locate -position 13:16 -look-for implementation -filename test.ml < /tmp/test.ml | jq .value
{
  "file": "test.ml",
  "pos": {
    "line": 4,
    "col": 6
  }
}

[voodoos]

So, of course it's linked to shapes of recursive modules:

 # 0.02 locate - shape_of_path
 initial: M<Test.0> . "f"[value]

 # 0.02 locate - shape_of_path
 reduced: Missing uid

 # 0.02 locate - from_path
 No definition uid, falling back to the declaration uid: Test.4

Surprisingly, the shape of M does looks decent enough:

# module rec M : sig
    val f : unit -> unit
  end = struct
    let f () = ()
  end
  
  and N : sig
    val foo : unit -> unit
  end = struct
    let foo () = M.f ()
  end
  
  ;;
{} {}
{
 "M"[module] -> {
                 "f"[value] -> <.59>;
                 };
 "N"[module] -> {
                 "foo"[value] -> <.60>;
                 };
 }

We probably fail to find that shape in the environment.