# 1) create empty list

a = nil();

if (!is_array(a) || (int) a != 0) exit(1);


# 2) prepend one element

a = cons(1, nil());

if ((int) a != 1 || a[0] != 1) exit(2);


# 3) prepend three elements

a = cons(1, cons(2, cons(3, nil())));

if ((int) a != 3 || a[0] != 1 || a[1] != 2 || a[2] != 3) exit(3);


# 4) head of empty list

a = head(nil());

if (!is_void(a)) exit(4);


# 5) head of three-element list

a = cons(1, cons(2, cons(3, nil())));
b = head(a);

if (b != 1) exit(5);


# 6) tail of empty list

a = tail(nil());

if (!is_array(a) || (int) a != 0) exit(6);


# 7) tail of three-element list

a = cons(1, cons(2, cons(3, nil())));
b = tail(a);

if ((int) b != 2 || b[0] != 2 || b[1] != 3) exit(7);


# 8) last of empty list

a = last(nil());

if (!is_void(a)) exit(8);


# 9) last of three-element list

a = cons(1, cons(2, cons(3, nil())));
b = last(a);

if (b != 3) exit(9);


# 10) init of empty list

a = init(nil());

if (!is_array(a) || (int) a != 0) exit(10);


# 11) init of three-element list

a = cons(1, cons(2, cons(3, nil())));
b = init(a);

if ((int) b != 2 || b[0] != 1 || b[1] != 2) exit(11);


# 12) take 2 elements from empty list

a = take(nil(), 2);

if (!is_array(a) || (int) a != 0) exit(12);


# 13) take 2 elements from three-element list

a = cons(1, cons(2, cons(3, nil())));
b = take(a, 2);

if ((int) b != 2 || b[0] != 1 || b[1] != 2) exit(13);


# 14) drop 2 elements from empty list

a = drop(nil(), 2);

if (!is_array(a) || (int) a != 0) exit(14);


# 15) drop 2 elements from three-element list

a = cons(1, cons(2, cons(3, nil())));
b = drop(a, 2);

if ((int) b != 1 || b[0] != 3) exit(15);


# 16) length of empty list

a = length(nil());

if (a != 0) exit(16);


# 17) length of three-element list

a = cons(1, cons(2, cons(3, nil())));
b = length(a);

if (b != 3) exit(17);


# 18) null test of empty list

a = null(nil());

if (!is_bool(a) || !a) exit(18);


# 19) null test of three-element list

a = cons(1, cons(2, cons(3, nil())));
b = null(a);

if (!is_bool(b) || b) exit(19);


# 20) elem test in empty list

a = nil();
b = elem(a, 2);

if (!is_bool(b) || b) exit(20);


# 21) positive elem test in three-element list

a = cons(1, cons(2, cons(3, nil())));
b = elem(a, 2);

if (!is_bool(b) || !b) exit(21);


# 22) negative elem test in three-element list

a = cons(1, cons(2, cons(3, nil())));
b = elem(a, 4);

if (!is_bool(b) || b) exit(22);


# 23) intersperse value in single-element list

a = mkarray(42);
b = intersperse(a, 0);

if ((int) b != 1 || b[0] != 42) exit(23);


# 24) intersperse value in multi-element list

a = explode("foo");
b = intersperse(a, "x");
c = implode(b);

if (c != "fxoxo") exit(24);


# 25) replicate zero times

a = replicate(42, 0);

if (!is_array(a) || (int) a != 0) exit(25);


# 26) replicate three times

a = replicate(42, 3);

if ((int) a != 3 || a[0] != 42 || a[1] != 42 || a[2] != 42) exit(26);


print("26 subtests ");