static Random random_random = new Random;

static int random(int n) {
  return random(random_random, n);
}

static int random(int n, Random r) { ret random(r, n); }

static int random(Random r, int n) {
  return n <= 0 ? 0 : r.nextInt(n);
}

static double random(double max) {
  return random()*max;
}

static double random() {
  return random_random.nextInt(100001)/100000.0;
}

static double random(double min, double max) {
  return min+random()*(max-min);
}

// min <= value < max
static int random(int min, int max) {
  return min+random(max-min);
}

static int random(int min, int max, Random r) {
  ret random(r, min, max);
}

static int random(Random r, int min, int max) {
  return min+random(r, max-min);
}

static <A> A random(L<A> l) {
  ret oneOf(l);
}

static <A> A random(Collection<A> c) {
  if (c instanceof L) ret random((L<A>) c);
  int i = random(l(c));
  ret collectionGet(c, i);
}

ifclass IntRange
static int random(IntRange r) {
  ret random(r.start, r.end);
}
endif

static <A, B> Pair<A, B> random(Map<A, B> map) {
  ret entryToPair(random(entries(map)));
}