anchor.diff:  test() ->
       test_destack(),
       test_tokens(),
  +    test_parse(),
       test_parse_tokens(),
       test_escape(),
       test_escape_attr(),
  
positive.code:     {{start_tag, Tag, Attrs, Singleton}, Rest3, S3};
  tokenize(Rest, S) ->
      tokenize_data(Rest, S, [], true).
  
  test_parse_tokens() ->
      D0 = [{doctype,["HTML","PUBLIC","-//W3C//DTD HTML 4.01 Transitional//EN"]},
  
negative.code:     tree(Rest, append_stack_child(norm({Tag, Attrs}), S));
  tree([{start_tag, Tag, Attrs, false} | Rest], S) ->
      tree(Rest, stack(norm({Tag, Attrs}), S));
  tree([T={comment, _Comment} | Rest], S) ->
      tree(Rest, append_stack_child(T, S));
  tree(L=[{data, _Data, _Whitespace} | _], S) ->
      case tree_data(L, true, []) of
          {_, true, Rest} -> 
  