static L<S> javaTokC(S s) {

  if (s == null) null;

  int l = s.length();

  new ArrayList<S> tok;

  int i = 0;

  while (i < l) {

    int j = i;

    char c, d;

    // scan for whitespace

    while (j < l) {

      c = s.charAt(j);

      d = j+1 >= l ? '\0' : s.charAt(j+1);

      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')

        ++j;

      else if (c == '/' && d == '*') {

        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));

        j = Math.min(j+2, l);

      } else if (c == '/' && d == '/') {

        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);

      } else

        break;

    }

    i = j;

    if (i >= l) break;

    c = s.charAt(i);

    d = i+1 >= l ? '\0' : s.charAt(i+1);

    // scan for non-whitespace

    if (c == '\'' || c == '"') {

      char opener = c;

      ++j;

      while (j < l) {

        if (s.charAt(j) == opener || s.charAt(j) == '\n') { // end at \n to not propagate unclosed string literal errors

          ++j;

          break;

        } else if (s.charAt(j) == '\\' && j+1 < l)

          j += 2;

        else

          ++j;

      }

    } else if (Character.isJavaIdentifierStart(c))

      do ++j; while (j < l && (Character.isJavaIdentifierPart(s.charAt(j)) || "'".indexOf(s.charAt(j)) >= 0)); // for stuff like "don't"

    else if (Character.isDigit(c)) {

      do ++j; while (j < l && Character.isDigit(s.charAt(j)));

      if (j < l && s.charAt(j) == 'L') ++j; // Long constants like 1L

    } else if (c == '[' && d == '[') {

      do ++j; while (j+1 < l && !s.substring(j, j+2).equals("]]"));

      j = Math.min(j+2, l);

    } else if (c == '[' && d == '=' && i+2 < l && s.charAt(i+2) == '[') {

      do ++j; while (j+2 < l && !s.substring(j, j+3).equals("]=]"));

      j = Math.min(j+3, l);

    } else

      ++j;

    tok.add(javaTok_substringC(s, i, j));

    i = j;

  }

  return tok;

}