static LS jsonTok(S s) {
  new LS tok;
  int l = l(s);
  
  int i = 0;
  while (i < l) {
    int j = i;
    char c; String cc;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      cc = s.substring(j, Math.min(j+2, l));
      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
        ++j;
      else if (cc.equals("/*")) {
        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));
        j = Math.min(j+2, l);
      } else if (cc.equals("//")) {
        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);
      } else
        break;
    }
    
    tok.add(s.substring(i, j));
    i = j;
    if (i >= l) break;
    c = s.charAt(i); // cc is not needed in rest of loop body

    // scan for non-whitespace (json strings, "null" identifier, numbers. everything else automatically becomes a one character token.)
    if (c == '\'' || c == '"') {
      char opener = c;
      ++j;
      while (j < l) {
        if (s.charAt(j) == opener) {
          ++j;
          break;
        } else if (s.charAt(j) == '\\' && j+1 < l)
          j += 2;
        else
          ++j;
      }
    } else if (Character.isLetter(c))
      do ++j; while (j < l && Character.isLetter(s.charAt(j)));
    else if (Character.isDigit(c))
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
    else
      ++j;

    tok.add(s.substring(i, j));
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  return tok;
}

Began life as a copy of #728