anchor.diff:       {text,<<"foo">>},
        {end_tag,"p"},
        {text,<<"grump">>},
  +     {tag,"br",[]},
  +     {end_tag,"br"},
        {tag,"x",[{"x","y"}]},
        {end_tag,"x"}]},
      {"<script>visual+basic = rules;</script>",
  
positive.code: tz({tag,""},?m("!",Str))                  -> {{'!',""},ws(Str)};
  tz({tag,""},?m("?",Str))                  -> {{que,""},ws(Str)};
  tz({tag,""},?m("/",Str))                  -> {{end_tag,""},ws(Str)};
  tz({tag,Tag},?D(X,S))when ?ev(X)          -> {{attr,"",{Tag,[]}},ws(S)};
  tz({tag,Tag},?d(X,Str))when ?ok(X)        -> {{tag,Tag++[X]},Str};
  
  
negative.code:     [{tag,"a",[]},
       {text,<<"...&lt;...">>},
       {end_tag,"a"}]},
     {"<P a=b c=d>hej<!-- tobbe --><b>svejsan</b>foo</p>grump<br/><x x=y />",
      [{tag,"p",[{"a","b"},{"c","d"}]},
       {text,<<"hej">>},
       {comment," tobbe "},
  