anchor.diff:                    end,
                     [replace_tree('<F>', FVar),
                      replace_tree('<Bin>', PrevBVar),
  -                   OneofClauseTransform]);
  +                   repeat_clauses('<oneof...>', OneofClauseTransforms)]);
           {maps, omitted} ->
  -            ?expr(case maps:find('fieldname', 'M') of
  -                      error        -> '<Bin>';
  -                      '<oneof...>' -> '<expr>'
  +            ?expr(case 'M' of
  +                      '<oneof...>' -> '<expr>';
  +                      _ -> '<Bin>'
                     end,
                     [replace_term('fieldname', FName),
                      replace_tree('M', MsgVar),
                      replace_tree('<Bin>', PrevBVar),
  -                   OneofClauseTransform])
  +                   repeat_clauses('<oneof...>', OneofClauseTransforms)])
       end.
   
   mk_field_encode_fn_name(MsgName, #?gpb_field{occurrence=repeated, name=FName})->
  
positive.code:                           end,
                            Replacements);
                  {maps, omitted} ->
                      ?expr(case maps:find('<FName>', 'M') of
                                error ->
                                    ok;
                                {ok, '<F>'} ->
                                    '<verify-fn>'('<F>', ['<FName>' | Path])
                            end,
                            [replace_tree('M', MsgVar) | Replacements])
              end
      end;
  field_verifier(#gpb_oneof{name=FName, fields=OFields}, FVar, MsgVar, Opts) ->
  
negative.code:                    || #?gpb_field{name=OFName, type=Type} <- OFields])]);
          {maps, omitted} ->
              ?expr(
                 case 'M' of
                     '<oneof-pattern>' ->
                         '<verify-fn>'('<OFVar>', ['<OFName>', '<FName>' | Path]);
                     '#{<FName> := <F>}' ->
                         mk_type_error(invalid_oneof, '<F>', ['<FName>' | Path]);
                     _ ->
                         ok
                 end,
                 [replace_tree('<F>', FVar),
                  replace_term('<FName>', FName),
                  replace_tree('M', MsgVar),
                  replace_tree('#{<FName> := <F>}', map_match([{FName, FVar}])),
                  repeat_clauses(
                    '<oneof-pattern>',
                    [begin
  