refactor_open: move to its own file

Author: trefis

src/analysis/refactor_open.ml

@@ -0,0 +1,48 @@
+open Std
+
+let qual_or_unqual_path mode leftmost_ident path p =
+  let rec aux acc (p : Path.t) =
+    match p with
+    | Pident ident ->
+      Ident.name ident :: acc
+    | Pdot (path', s) when
+        mode = `Unqualify && Path.same path path' ->
+      s :: acc
+    | Pdot (path', s) when
+        mode = `Qualify && s = leftmost_ident ->
+      s :: acc
+    | Pdot (path', s) ->
+      aux (s :: acc) path'
+    | _ -> raise Not_found
+  in
+  aux [] p |> String.concat ~sep:"."
+
+(* checks if the (un)qualified longident has a different length, i.e., has changed
+
+   XXX(Ulugbek): computes longident length using [loc_start] and [loc_end], hence
+   it doesn't work for multiline longidents because we can't compute their length *)
+let same_longident new_lident { Location. loc_start; loc_end; _ } =
+  let old_longident_len = Lexing.column loc_end - Lexing.column loc_start in
+  loc_start.Lexing.pos_lnum = loc_end.Lexing.pos_lnum &&
+  String.length new_lident = old_longident_len
+
+
+let get_rewrites ~mode typer pos =
+  match Mbrowse.select_open_node (Mtyper.node_at typer pos) with
+  | None | Some (_, _, []) -> []
+  | Some (orig_path, longident, ((_, node) :: _)) ->
+    let paths =
+      Browse_tree.all_occurrences_of_prefix ~strict_prefix:true orig_path node
+    in
+    let paths = List.concat_map ~f:snd paths in
+    let leftmost_ident = Longident.flatten longident |> List.hd in
+    List.filter_map paths ~f:(fun {Location. txt = path; loc} ->
+      if loc.Location.loc_ghost || Location_aux.compare_pos pos loc > 0 then
+        None
+      else
+        match qual_or_unqual_path mode leftmost_ident orig_path path with
+        | s when same_longident s loc -> None
+        | s -> Some (s, loc)
+        | exception Not_found -> None
+    )
+    |> List.sort_uniq ~cmp:(fun (_,l1) (_,l2) -> Location_aux.compare l1 l2)

src/analysis/refactor_open.mli

@@ -0,0 +1,6 @@
+
+val get_rewrites
+  : mode:[> `Qualify | `Unqualify ]
+  -> Mtyper.result
+  -> Lexing.position
+  -> (string * Location.t) list