// f: A -> Comparable
static <A> L<A> sortByCalculatedFieldDesc_inPlace(L<A> l, fO f) {
  sort(l, new Comparator<A>() {
    public int compare(A b, A a) {
      ret stdcompare((O) callF(f, a), (O) callF(f, b));
    }
  });
  ret l;
}

static <A> L<A> sortByCalculatedFieldDesc_inPlace(O f, L<A> c) {
  ret sortByCalculatedFieldDesc_inPlace(c, f);
}