Remove uses of Handlers in type of selection (#1710)

* Revert move of `Handlers` from ast_editor

* Update type_selection listeners

src/ast_editor.ml

@@ -1,5 +1,33 @@
 open Import
 
+exception User_error of string
+
+module Handlers = struct
+  let unpwrap = function
+    | `Ok () -> ()
+    | `Error err_msg -> show_message `Error "%s" err_msg
+  ;;
+
+  let w1 f x =
+    try `Ok (f x) with
+    | User_error e -> `Error e
+  ;;
+
+  let ws f x y =
+    match f x with
+    | `Ok f' ->
+      (try `Ok (f' y) with
+       | User_error e -> `Error e)
+    | `Error e -> `Error e
+  ;;
+
+  let w2 f = ws (w1 f)
+  let w3 f x = ws (w2 f x)
+  let w4 f x y = ws (w3 f x y)
+  let w5 f x y z = ws (w4 f x y z)
+  let _w6 f x y z w = ws (w5 f x y z w)
+end
+
 let read_html_file () =
   let filename = Node.__dirname () ^ "/../astexplorer/dist/index.html" in
   Fs.readFile filename

src/import.ml

@@ -253,31 +253,3 @@ module Ocaml_version = struct
 
   include Ocaml_version
 end
-
-exception User_error of string
-
-module Handlers = struct
-  let unpwrap = function
-    | `Ok () -> ()
-    | `Error err_msg -> show_message `Error "%s" err_msg
-  ;;
-
-  let w1 f x =
-    try `Ok (f x) with
-    | User_error e -> `Error e
-  ;;
-
-  let ws f x y =
-    match f x with
-    | `Ok f' ->
-      (try `Ok (f' y) with
-       | User_error e -> `Error e)
-    | `Error e -> `Error e
-  ;;
-
-  let w2 f = ws (w1 f)
-  let w3 f x = ws (w2 f x)
-  let w4 f x y = ws (w3 f x y)
-  let w5 f x y z = ws (w4 f x y z)
-  let _w6 f x y z w = ws (w5 f x y z w)
-end

src/type_selection.ml

@@ -194,15 +194,9 @@ let enable_reset () =
       state := None
     | _ -> ()
   in
-  [ (let listener event =
-       let listener = onDidChangeTextEditorSelection_listener in
-       Handlers.unpwrap (Handlers.w1 listener event)
-     in
+  [ (let listener = onDidChangeTextEditorSelection_listener in
      Window.onDidChangeTextEditorSelection () ~listener ())
-  ; (let listener event =
-       let listener = onDidChangeActiveTextEditor_listener in
-       Handlers.unpwrap (Handlers.w1 listener event)
-     in
+  ; (let listener = onDidChangeActiveTextEditor_listener in
      Window.onDidChangeActiveTextEditor () ~listener ())
   ]
 ;;