static L<S> splitAtTokenIndices(LS tok, L<Int> indices) {
  new L<S> l;
  for (int iI = -1; iI < l(indices); iI++) {
    int i = or(get(indices, iI), 0)+1;
    int j = or(get(indices, iI+1), l(tok));
    l.add(trimJoin(tok.subList(i, j)));
  }
  ret l;
}