static LS tok_splitAtAnyOperator(S s) {
  ret tok_splitAtAnyOperator(javaTok(s));
}

static LS tok_splitAtAnyOperator(LS tok) {
  new LS l;
  int i = 1;
  while ping (i < l(tok)) {
    S t;
    int lastI = i, j = i;
    while (l(t = get(tok, j)) == 1 && !startsWithLetterOrDigit(t))
      j += 2;
    addIfNempty(l, trimJoinSubList(tok, i, j));
    i = j;
    while (j < l(tok) && !(l(t = get(tok, j)) == 1 && !startsWithLetterOrDigit(t)))
      j += 2;
    addIfNempty(l, trimJoinSubList(tok, i, j));
    i = j;
    assertTrue("safety", i > lastI);
  }
  ret l;
}