anchor.diff:  
   test_all() ->
       [1199344435545.0, 1] = decode(<<"[1199344435545.0,1]">>),
  +    test_encoder_utf8(),
       test_one(e2j_test_vec(utf8), 1).
   
   test_one([], _N) ->
  
positive.code:                    [$r, $\\ | Acc];
                 $\t ->
                     [$t, $\\ | Acc];
                 C when C >= 0, C < $\s; C >= 16#7f, C =< 16#10FFFF ->
                     [unihex(C) | Acc];
                 C when C < 16#7f ->
                     [C | Acc];
                 _ ->
                     exit({json_encode, {bad_char, C}})
             end,
      json_encode_string_unicode(Cs, Acc1).
  
  hexdigit(C) when C >= 0, C =< 9 ->
      C + $0;
  
negative.code: %% @type json_term() = json_string() | json_number() | json_array() |
  %%                     json_object()
  
  -record(encoder, {handler=null,
                    utf8=false}).
  
  -record(decoder, {object_hook=null,
                    offset=0,
  