Improve loc assignment

Author: shulhi

compiler/syntax/src/res_core.ml

@@ -4909,16 +4909,11 @@ and parse_type_constructor_declaration_with_bar p =
     let start_pos = p.Parser.start_pos in
     Parser.next p;
     let constr = parse_type_constructor_declaration ~start_pos p in
+    (* if there is doc comment attached, we ensure that the constructor is placed at the same line
+       as the bar *)
     let pcd_loc =
       if has_doc_comment then
-        {
-          constr.Parsetree.pcd_loc with
-          loc_end =
-            {
-              constr.pcd_loc.loc_end with
-              pos_lnum = constr.pcd_loc.loc_end.pos_lnum + 1;
-            };
-        }
+        {constr.Parsetree.pcd_loc with loc_end = start_pos}
       else constr.pcd_loc
     in
     Some
@@ -4968,16 +4963,11 @@ and parse_type_constructor_declarations ?first p =
       let start_pos = p.Parser.start_pos in
       ignore (Parser.optional p Token.Bar);
       let constr = parse_type_constructor_declaration ~start_pos p in
+      (* if there is doc comment attached, we ensure that the constructor is placed at the same line
+         as the bar *)
       let pcd_loc =
         if has_doc_comment then
-          {
-            constr.Parsetree.pcd_loc with
-            loc_end =
-              {
-                constr.pcd_loc.loc_end with
-                pos_lnum = constr.pcd_loc.loc_end.pos_lnum + 1;
-              };
-          }
+          {constr.Parsetree.pcd_loc with loc_end = start_pos}
         else constr.pcd_loc
       in
       {

compiler/syntax/src/res_printer.ml

@@ -1549,11 +1549,15 @@ and print_constructor_declarations ~state ~private_flag
 
 and print_constructor_declaration2 ~state i
     (cd : Parsetree.constructor_declaration) cmt_tbl =
-  let comment_attrs, attrs = ParsetreeViewer.partition_doc_comment_attributes cd.pcd_attributes in
+  let comment_attrs, attrs =
+    ParsetreeViewer.partition_doc_comment_attributes cd.pcd_attributes
+  in
   let comment_doc =
     match comment_attrs with
     | [] -> Doc.nil
-    | comment_attrs -> print_doc_comments ~sep:Doc.hard_line ~state cmt_tbl comment_attrs in
+    | comment_attrs ->
+      print_doc_comments ~sep:Doc.hard_line ~state cmt_tbl comment_attrs
+  in
   let attrs = print_attributes ~state attrs cmt_tbl in
   let is_dot_dot_dot = cd.pcd_name.txt = "..." in
   let bar =