anchor.diff:         [mk_fn(d_read_field_def_, MsgName), FieldVars]),
        if ReadFieldCases == [] ->
                f("    case Key band 7 of  %% WireType~n"
  -               "        0 -> skip_varint_~s(Rest, 1, 1~s);~n"
  -               "        1 -> skip_64_~s(Rest, 1, 1~s);~n"
  -               "        2 -> skip_length_delimited_~s(Rest, 0, 0~s);~n"
  -               "        5 -> skip_32_~s(Rest, 1, 1~s)~n"
  +               "        0 -> 'skip_varint_~s'(Rest, 1, 1~s);~n"
  +               "        1 -> 'skip_64_~s'(Rest, 1, 1~s);~n"
  +               "        2 -> 'skip_length_delimited_~s'(Rest, 0, 0~s);~n"
  +               "        5 -> 'skip_32_~s'(Rest, 1, 1~s)~n"
                  "    end;~n",
                  [MsgName, FieldVars,
                   MsgName, FieldVars,
  
positive.code:                "~s"
                 "        _ ->~n"
                 "            case Key band 7 of %% wiretype~n"
                 "                0 -> skip_varint_~s(Rest, Msg);~n"
                 "                1 -> skip_64_~s(Rest, Msg);~n"
                 "                2 -> skip_length_delimited_~s(Rest,0,0,Msg);~n"
                 "                5 -> skip_32_~s(Rest, Msg)~n"
                 "            end~n"
                 "    end;~n",
                 [ReadFieldCases,
  
negative.code:        "    Key = X bsl N + Acc,~n", [mk_fn(d_read_field_def_, MsgName)]),
       if ReadFieldCases == [] ->
               f("    case Key band 7 of  %% WireType~n"
                 "        0 -> 'skip_varint_~s'(Rest, Msg);~n"
                 "        1 -> 'skip_64_~s'(Rest, Msg);~n"
                 "        2 -> 'skip_length_delimited_~s'(Rest, 0, 0, Msg);~n"
                 "        5 -> 'skip_32_~s'(Rest, Msg)~n"
                 "    end;~n",
                 [MsgName,MsgName,MsgName,MsgName]);
          true ->
  