sS ai_indentToCurlyBraces(S s) {
  L<S> lines = lines(s);
  for i over lines: {
    int indent = indentCount(lines.get(i));
    int j = i;
    while (j+1 < l(lines) && indentCount(lines.get(j+1)) > indent) ++j;
    if (j > i) {
      lines.set(i, lines.get(i) + " {");
      lines.set(j, lines.get(j) + " }");
    }
    //i = j;
  }
  ret lines(lines);
}