sclass StructureStringIndenter {

  // how many levels to indent, max

  settable int levels = 100;

  // inline lowest levels of char count is not higher than this

  settable int inlineChars = 40;

  settable bool verbose;

  // internal

  LS tok;

  Map<Int> bracketMap;

  S get(S s) {

    if (s == null) null;

    tok = javaTokForStructure(s);

    int n = l(tok);

    bracketMap = getBracketMap(tok, l1 isOpeningBracket, l1 isClosingBracket);

    // being careful because this.levels might be Int.MAX_VALUE

    int levels = clampToInt(this.levels*2L);

    new StringBuilder buf;

    int indent = 0;

    for i to n: {

      S t = tok.get(i);

      if (isOpeningBracket(t)) {

        S prev = _get(tok, i-2);

        Int j = or(bracketMap.get(i), n);

        if (j != null &&

          (eq(prev, "intarray")

          || !tokenRangeLongerThanNChars(tok, i+1, j+1, inlineChars))) {

          // ONE LINE

          buf.append(joinSubList(tok, i, j+1));

          i = j;

        } else {

          // MULTIPLE LINES

          if (verbose)

            print("Bracket part longer than " + inlineChars + " chars: " + quote(shortenJoinSubList(inlineChars, tok, i, j+1)));

          indent += 2;

          buf.append(t);

          if (indent <= levels)

            buf.append("\n").append(spaces(indent));

        }

      } else if (isClosingBracket(t)) {

        indent -= 2;

        if (indent < levels)

          buf.append("\n").append(spaces(indent));

        buf.append(t);

      } else if (indent <= levels && eq(t, ",")) {

        buf.append(t).append("\n").append(spaces(indent));

        i++;

      } else

        buf.append(t);

    }

    ret str(buf);

  }

}