anchor.diff:      skip_whitespace(Rest, ?INC_CHAR(S, C));
   skip_whitespace(Rest, S) ->
       {Rest, S}.
  +
  +find_qgt([], S) ->
  +    {[], S};
  +find_qgt("?>" ++ Rest, S) ->
  +    {Rest, ?ADV_COL(S, 2)};
  +find_qgt([C | Rest], S) ->
  +    find_qgt(Rest, ?INC_CHAR(S, C)).
   
   find_gt([], S, HasSlash) ->
       {[], S, HasSlash};
  
positive.code:     {lists:reverse(Acc), [], S};
  tokenize_attributes(Rest=">" ++ _, S, Acc) ->
      {lists:reverse(Acc), Rest, S};
  tokenize_attributes(Rest="/" ++ _, S, Acc) ->
      {lists:reverse(Acc), Rest, S};
  tokenize_attributes([C | Rest], S, Acc) when ?IS_WHITESPACE(C) ->
  
negative.code:     tokenize_doctype(Rest, ?ADV_COL(S, 10), []);
  tokenize("<![CDATA[" ++ Rest, S) ->
      tokenize_cdata(Rest, ?ADV_COL(S, 9), []);
  tokenize("<?" ++ Rest, S) ->
      {Tag, Rest1, S1} = tokenize_literal(Rest, ?ADV_COL(S, 2), []),
      {Attrs, Rest2, S2} = tokenize_attributes(Rest1, S1, []),
      {Rest3, S3} = find_qgt(Rest2, S2),
      {{pi, Tag, Attrs}, Rest3, S3};
  tokenize("&" ++ Rest, S) ->
      tokenize_charref(Rest, ?INC_COL(S), []);
  tokenize("</" ++ Rest, S) ->
  