static Pair<LS, Map<Int>> ai_parseTokenRefNumbers(LS tok) {
  tok = tok_combineSquareBrackets_keep(tok);
  new LS out;
  new Map<S, Int> refToToken;
  new Map<Int> map;
  for i over tok: {
    S t = get(tok, i+1);
    if (even(i) && isSquareBracketed(t)) {
      t = deSquareBracket(t);
      if (startsWith(t, "*"))
        refToToken.put(dropFirst(t), l(out)-1);
      else
        mapPut(map, l(out)-1, refToToken.get(t));
      ++i;
    } else
      out.add(tok.get(i));
  }
  ret pair(out, map);
}