// tok should be the output of htmlcoarsetok
static L<S> dropAllTags(L<S> tok) {
  new L<S> list;
  for (int i = 1; i < tok.size(); i += 2) {
    S t = tok.get(i);
    if (t.startsWith("<")) {
      list.set(list.size()-1, list.get(list.size()-1) + tok.get(i+1));
      ++i;
    } else
      list.add(tok.get(i));
  }
  return list;
}

// alternatively, call this convenient function
static S dropAllTags(S html) {
  return join(dropAllTags(htmlcoarsetok(html)));
}