v/vlib/builtin/array_test.v

fn test_pointer() {
	mut arr := []&int{}
	a := 1
	b := 2
	c := 3
	arr << &a
	arr << &b
	arr << &c
	assert *arr[0] == 1
	arr[1] = &c
	assert *arr[1] == 3
	mut d_arr := [arr] // [][]&int
	d_arr << arr
	assert *d_arr[0][1] == 3
	println(*d_arr[0][1])
	assert *d_arr[1][0] == 1
}

fn test_assign() {
	mut arr := [2, 4, 8, 16, 32, 64, 128]

	arr[0] = 2
	arr[1] &= 255
	arr[2] |= 255
	arr[3] <<= 4
	arr[4] >>= 4
	arr[5] %= 5
	arr[6] ^= 3

	assert arr[0] == 2
	assert arr[1] == 4 & 255
	assert arr[2] == 8 | 255
	assert arr[3] == 16 << 4
	assert arr[4] == 32 >> 4
	assert arr[5] == 64 % 5
	assert arr[6] == 128 ^ 3
}

fn test_ints() {
	mut a := [1, 5, 2, 3]
	assert a.len == 4
	assert a[0] == 1
	assert a[2] == 2
	assert a.last() == 3
	a << 4
	assert a.len == 5
	assert a[4] == 4
	assert a.last() == 4
	s := a.str()
	assert s == '[1, 5, 2, 3, 4]'
	assert a[1] == 5
	assert a.last() == 4
}

fn test_deleting() {
	mut a := [1, 5, 2, 3, 4]
	assert a.len == 5
	assert a.str() == '[1, 5, 2, 3, 4]'
	a.delete(0)
	assert a.str() == '[5, 2, 3, 4]'
	assert a.len == 4
	a.delete(1)
	assert a.str() == '[5, 3, 4]'
	assert a.len == 3
	a.delete(a.len - 1)
	assert a.str() == '[5, 3]'
	assert a.len == 2
}

fn test_short() {
	a := [1, 2, 3]
	assert a.len == 3
	assert a.cap == 3
	assert a[0] == 1
	assert a[1] == 2
	assert a[2] == 3
}

fn test_large() {
	mut a := [0].repeat(0)
	for i in 0..10000 {
		a << i
	}
	assert a.len == 10000
	assert a[234] == 234
}

struct Chunk {
	val string
}

struct Kkk {
	q []Chunk
}

fn test_empty() {
	mut chunks := []Chunk{}
	a := Chunk{}
	assert chunks.len == 0
	chunks << a
	assert chunks.len == 1
	chunks = []
	assert chunks.len == 0
	chunks << a
	assert chunks.len == 1
}

fn test_push() {
	mut a := []int{}
	a << 1
	a << 3
	assert a[1] == 3
	assert a.str() == '[1, 3]'
}

fn test_insert() {
	mut a := [1, 2]
	a.insert(0, 3)
	assert a[0] == 3
	assert a[2] == 2
	assert a.len == 3
	a.insert(1, 4)
	assert a[1] == 4
	assert a[2] == 1
	assert a.len == 4
	a.insert(4, 5)
	assert a[4] == 5
	assert a[3] == 2
	assert a.len == 5
	mut b := []f64{}
	assert b.len == 0
	b.insert(0, f64(1.1))
	assert b.len == 1
	assert b[0] == f64(1.1)
}

fn test_insert_many() {
	mut a := [3, 4]
	a.insert(0, [1, 2])
	assert a == [1,2,3,4]
	b := [5,6]
	a.insert(1, b)
	assert a == [1,5,6,2,3,4]
}

fn test_prepend() {
	mut a := []int{}
	assert a.len == 0
	a.prepend(1)
	assert a.len == 1
	assert a[0] == 1
	mut b := []f64{}
	assert b.len == 0
	b.prepend(f64(1.1))
	assert b.len == 1
	assert b[0] == f64(1.1)
}

fn test_prepend_many() {
	mut a := [3,4]
	a.prepend([1,2])
	assert a == [1,2,3,4]
	b := [5,6]
	a.prepend(b)
	assert a == [5,6,1,2,3,4]
}

fn test_strings() {
	a := ['a', 'b', 'c']
	assert a.str() == "['a', 'b', 'c']"
}

/*
fn test_compare_ints() {
    assert compare_ints(1, 2) == -1
    assert compare_ints(2, 1) == 1
    assert compare_ints(0, 0) == 0

    a := 1
    b := 2
    assert compare_ints(a, b) == -1
    assert compare_ints(b, a) == 1
    assert compare_ints(a, a) == 0
}
*/

fn test_repeat() {
	{
		a := [0].repeat(5)
		assert a.len == 5
		assert a[0] == 0 && a[1] == 0 && a[2] == 0 && a[3] == 0 && a[4] == 0
	}
	{
		a := [1.1].repeat(10)
		assert a[0] == 1.1
		assert a[5] == 1.1
		assert a[9] == 1.1
	}
	{
		a := [i64(-123)].repeat(10)
		assert a[0] == -123
		assert a[5] == -123
		assert a[9] == -123
	}
	{
		a := [u64(123)].repeat(10)
		assert a[0] == 123
		assert a[5] == 123
		assert a[9] == 123
	}
	{
		a := [1.1].repeat(10)
		assert a[0] == 1.1
		assert a[5] == 1.1
		assert a[9] == 1.1
	}
	{
		a := [1, 2].repeat(2)
		assert a[0] == 1
		assert a[1] == 2
		assert a[2] == 1
		assert a[3] == 2
	}
	{
		a := ['1', 'abc'].repeat(2)
		assert a[0] == '1'
		assert a[1] == 'abc'
		assert a[2] == '1'
		assert a[3] == 'abc'
	}
	{
		mut a := ['1', 'abc'].repeat(0)
		assert a.len == 0
		a << 'abc'
		assert a[0] == 'abc'
	}
}

fn test_right() {
	a := [1, 2, 3, 4]
	c := a[1..a.len]
	d := a[1..]
	assert c[0] == 2
	assert c[1] == 3
	assert d[0] == 2
	assert d[1] == 3
}

fn test_left() {
	a := [1, 2, 3]
	c := a[0..2]
	d := a[..2]
	assert c[0] == 1
	assert c[1] == 2
	assert d[0] == 1
	assert d[1] == 2
}

fn test_slice() {
	a := [1, 2, 3, 4]
	b := a.slice(2, 4)
	assert b.len == 2
	assert a.slice(1, 2).len == 1
	assert a.len == 4
}


fn test_push_many() {
	mut a := [1, 2, 3]
	b := [4, 5, 6]
	a << b
	assert a.len == 6
	assert a[0] == 1
	assert a[3] == 4
	assert a[5] == 6
}

fn test_reverse() {
	a := [1, 2, 3, 4]
	b := ['test', 'array', 'reverse']
	c := a.reverse()
	println(c)
	d := b.reverse()
	for i, _ in c {
		assert c[i] == a[a.len - i - 1]
	}
	for i, _ in d {
		assert d[i] == b[b.len - i - 1]
	}
	e := []int{}
	f := e.reverse()
	assert f.len == 0
}

const (
	c_n = 5
)

struct Foooj {
	a [5]int // c_n
}

fn test_fixed() {
	mut nums := [4]int{}
	//x := nums[1..3]
	//assert x.len == 2
	assert nums[0] == 0
	assert nums[1] == 0
	assert nums[2] == 0
	assert nums[3] == 0
	nums[1] = 7
	assert nums[1] == 7
	nums2 := [5]int{} // c_n
	assert nums2[c_n - 1] == 0
}

fn modify(mut numbers []int) {
	numbers[0] = 777
}

fn test_mut_slice() {
	/*
	QTODO
	mut n := [1, 2, 3]
	//modify(mut n)
	modify(mut n[..2])
	assert n[0] == 777
	modify(mut n[2..])
	assert n[2] == 777
	println(n)
	*/
}

fn double_up(mut a []int) {
	for i := 0; i < a.len; i++ {
		a[i] = a[i]*2
	}
}

fn double_up_v2(mut a []int) {
	for i, _ in a {
		a[i] = a[i]*2 // or val*2, doesn't matter
	}
}

fn test_mut_arg() {
	mut arr := [1,2,3,4,5,6,7,8,9,10]
	double_up(mut arr)
	assert arr.str() == '[2, 4, 6, 8, 10, 12, 14, 16, 18, 20]'
	arr = [1,2,3,4,5,6,7,8,9,10]
	double_up_v2(mut arr)
	assert arr.str() == '[2, 4, 6, 8, 10, 12, 14, 16, 18, 20]'
}

fn test_clone() {
	nums := [1, 2, 3, 4, 100]
	nums2 := nums.clone()
	assert nums2.len == 5
	assert nums.str() == '[1, 2, 3, 4, 100]'
	assert nums2.str() == '[1, 2, 3, 4, 100]'
	assert nums.slice(1, 3).str() == '[2, 3]'
}

fn test_mutli_array_clone() {
    // 2d array_int
    mut a2_1 := [[1, 2, 3], [4, 5, 6]]
    mut a2_2 := a2_1.clone()

    a2_1[0][1] = 0
    a2_2[1][0] = 0

    assert a2_1 == [[1, 0, 3], [4, 5, 6]]
    assert a2_2 == [[1, 2, 3], [0, 5, 6]]

    // 2d array_string
    mut b2_1 := [['1', '2', '3'], ['4', '5', '6']]
    mut b2_2 := b2_1.clone()

    b2_1[0][1] = '0'
    b2_2[1][0] = '0'

    assert b2_1 == [['1', '0', '3'], ['4', '5', '6']]
    assert b2_2 == [['1', '2', '3'], ['0', '5', '6']]

    // 3d array_int
    mut a3_1 := [[[1,1], [2,2], [3,3]], [[4,4], [5,5], [6,6]]]
    mut a3_2 := a3_1.clone()

    a3_1[0][0][1] = 0
    a3_2[0][1][0] = 0

    assert a3_1 == [[[1, 0], [2, 2], [3, 3]], [[4, 4], [5, 5], [6, 6]]]
    assert a3_2 == [[[1, 1], [0, 2], [3, 3]], [[4, 4], [5, 5], [6, 6]]]

    // 3d array_string
    mut b3_1 := [[['1','1'], ['2','2'], ['3','3']], [['4','4'], ['5','5'], ['6','6']]]
    mut b3_2 := b3_1.clone()

    b3_1[0][0][1] = '0'
    b3_2[0][1][0] = '0'

    assert b3_1 == [[['1','0'], ['2','2'], ['3','3']], [['4','4'], ['5','5'], ['6','6']]]
    assert b3_2 == [[['1','1'], ['0','2'], ['3','3']], [['4','4'], ['5','5'], ['6','6']]]
}

fn test_doubling() {
	mut nums := [1, 2, 3, 4, 5]
	for i in 0..nums.len {
		nums[i] *= 2
	}
	println(nums.str())
	assert nums.str() == '[2, 4, 6, 8, 10]'
}

struct Test2 {
	one int
	two int
}

struct Test {
	a string
mut:
	b []Test2
}

// TODO: default array/struct str methods
fn (ta []Test2) str() string {
	mut s := '['
	for i, t in ta {
		s += t.str()
		if i < ta.len-1 {
			s += ', '
		}
	}
	s += ']'
	return s
}

fn (t Test2) str() string {
	return '{$t.one $t.two}'
}

fn (t Test) str() string {
	return '{$t.a $t.b}'
}

fn test_struct_print() {
	mut a := Test{
		a: 'Test'
		b: []
	}
	b := Test2{
		one: 1
		two: 2
	}
	a.b << b
	a.b << b
	assert a.str() == '{Test [{1 2}, {1 2}]}'
	assert b.str() == '{1 2}'
	assert a.b.str() == '[{1 2}, {1 2}]'
}

fn test_single_element() {
	mut a := [1]
	a << 2
	assert a.len == 2
	assert a[0] == 1
	assert a[1] == 2
	println(a)
}

fn test_find_index() {
	// string
	a := ['v', 'is', 'great']
	assert a.index('v') == 0
	assert a.index('is') == 1
	assert a.index('gre') == -1
	// int
	b := [1, 2, 3, 4]
	assert b.index(1) == 0
	assert b.index(4) == 3
	assert b.index(5) == -1
	// byte
	c := [0x22, 0x33, 0x55]
	assert c.index(0x22) == 0
	assert c.index(0x55) == 2
	assert c.index(0x99) == -1
	// char
	d := [`a`, `b`, `c`]
	assert d.index(`b`) == 1
	assert d.index(`c`) == 2
	assert d.index(`u`) == -1
}

fn test_multi() {
	a := [[1, 2, 3], [4, 5, 6]]
	assert a.len == 2
	assert a[0].len == 3
	assert a[0][0] == 1
	assert a[0][2] == 3
	assert a[1][2] == 6
	// TODO
	// b :=  [ [[1,2,3],[4,5,6]], [[1,2]] ]
	// assert b[0][0][0] == 1
}

fn test_in() {
	a := [1, 2, 3]
	assert 1 in a
	assert 2 in a
	assert 3 in a
	assert !(4 in a)
	assert !(0 in a)
	assert 0 !in a
	assert 4 !in a
	b := [1, 4, 0]
	c := [3, 6, 2, 0]
	assert 0 in b
	assert 0 in c
}

fn sum(prev int, curr int) int {
	return prev + curr
}

fn sub(prev int, curr int) int {
	return prev - curr
}

/*
fn test_reduce() {
	a := [1, 2, 3, 4, 5]
	b := a.reduce(sum, 0)
	c := a.reduce(sum, 5)
	d := a.reduce(sum, -1)
	assert b == 15
	assert c == 20
	assert d == 14
	e := [1, 2, 3]
	f := e.reduce(sub, 0)
	g := e.reduce(sub, -1)
	assert f == -6
	assert g == -7
}
*/

fn filter_test_helper_1(a int) bool {
	return a > 3
}

fn test_filter() {
	a := [1, 2, 3, 4, 5, 6]
	b := a.filter(it % 2 == 0)
	assert b.len == 3
	assert b[0] == 2
	assert b[1] == 4
	assert b[2] == 6
	c := ['v', 'is', 'awesome']
	d := c.filter(it.len > 1)
	assert d[0] == 'is'
	assert d[1] == 'awesome'
	////////
	arr :=[1,2,3,4,5,6,7,8,9,10]
	println(arr.filter(it % 2 == 0 || it % 3 == 0))
	assert true
	assert [1,2,3].len == 3
	mut mut_arr := [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
	mut_arr = mut_arr.filter(it < 4)
	assert mut_arr.len == 3
	assert a.filter(filter_test_helper_1) == [4,5,6]
	assert [1,5,10].filter(filter_test_helper_1) == [5,10]

	// TODO
	//assert arr.filter(arr % 2).len == 5
}

fn test_anon_fn_filter() {
	filter_num := fn (i int) bool {
		return i % 2 == 0
	}
	assert [1,2,3,4,5].filter(filter_num) == [2,4]
}

fn test_anon_fn_arg_filter() {
	a := [1,2,3,4].filter(fn (i int) bool {
		return i % 2 == 0
	})

	assert a == [2,4]
}

fn map_test_helper_1(i int) int {
	return i * i
}
fn map_test_helper_2(i int, b string) int {
	return i + b.len
}
fn map_test_helper_3(i int, b []string) int {
	return i + b.map(it.len)[i % b.len]
}

fn test_map() {
	nums := [1, 2, 3, 4, 5, 6]
	strs := ['v', 'is', 'awesome']

	//assert nums.map() == <error>
	//assert nums.map(it, 'excessive') == <error>

	// identity
	assert nums.map(it) == [1, 2, 3, 4, 5, 6]
	assert strs.map(it) == ['v', 'is', 'awesome']
	assert nums.map(it - it) == [0,0,0,0,0,0]
	assert nums.map(it - it)[0] == 0

	// type switch
	assert nums.map(it * 10) == [10, 20, 30, 40, 50, 60]
	assert nums.map(it * it) == [1, 4, 9, 16, 25, 36]
	assert nums.map('$it') == ['1', '2', '3', '4', '5', '6']
	assert nums.map(it % 2 == 0) == [false, true, false, true, false, true]

	assert strs.map(it.to_upper()) == ['V', 'IS', 'AWESOME']
	assert strs.map(it == 'awesome') == [false, false, true]
	assert strs.map(it.len in nums) == [true, true, false]
	assert strs.map(int(7)) == [7, 7, 7]

	// external func
	assert nums.map(map_test_helper_1(it)) == [1, 4, 9, 16, 25, 36]
	assert nums.map(map_test_helper_2(it, 'bb')) == [3, 4, 5, 6, 7, 8]
	assert nums.map(map_test_helper_3(it, strs)) == [3, 9, 4, 6, 12, 7]

	// empty array as input
	assert []int{len:0}.map(it * 2) == []

	// nested maps (where it is of same type)
	assert nums.map( strs.map(int(7)) == [7, 7, 7] ) == [true, true, true, true, true, true]
	assert nums.map( '$it' + strs.map('a')[0] ) == ['1a', '2a', '3a', '4a', '5a', '6a']
	assert nums.map( it + strs.map(int(7))[0] ) == [8, 9, 10, 11, 12, 13]
	assert nums.map( it + strs.map(it.len)[0] ) == [2, 3, 4, 5, 6, 7]
	assert strs.map( it.len + strs.map(it.len)[0] ) == [2, 3, 8]

	// nested (different it types)
	assert strs.map( it[ nums.map(it - it)[0] ] ) == [`v`, `i`, `a`]
	assert nums[0..3].map('$it' + strs.map(it)[it-1]) == ['1v','2is','3awesome']

	assert nums.map(map_test_helper_1) == [1,4,9,16,25,36]
	assert [1,5,10].map(map_test_helper_1) == [1,25,100]

	assert nums == [1, 2, 3, 4, 5, 6]
	assert strs == ['v', 'is', 'awesome']
}

fn test_anon_fn_map() {
	add_num := fn (i int) int {
		return i + 1
	}
	assert [1,2,3].map(add_num) == [2,3,4]
}

fn test_mutli_anon_fn_map() {
	a := [1,2,3].map(fn (i int) int {
		return i + 1
	})

	b := [1,2,3].map(fn (i int) int {
		return i + 2
	})
	assert a == [2,3,4]
	assert b == [3,4,5]
}

fn test_anon_fn_arg_map() {
	a := [1,2,3].map(fn (i int) int {
		return i + 1
	})

	assert a == [2,3,4]
}

fn test_array_str() {
	numbers := [1, 2, 3]
	assert numbers == [1,2,3]
	numbers2 := [numbers, [4, 5, 6]] // dup str() bug
	_ = numbers2
	assert true
	assert numbers.str() == '[1, 2, 3]'
	// QTODO
	//assert numbers2.str() == '[[1, 2, 3], [4, 5, 6]]'

}

fn test_eq() {
	/*
	assert [5, 6, 7].eq([6, 7]) == false
	assert [`a`, `b`].eq([`a`, `b`]) == true
	*/
}

struct User {
	age int
	name string
}

fn test_sort() {
	mut a := ['hi', '1', '5', '3']
	a.sort()
	assert a[0] == '1'
	assert a[1] == '3'
	assert a[2] == '5'
	assert a[3] == 'hi'
	//
	mut nums := [67, -3, 108, 42, 7]
	nums.sort()
	assert nums[0] == -3
	assert nums[1] == 7
	assert nums[2] == 42
	assert nums[3] == 67
	assert nums[4] == 108
	//
	nums.sort(a < b)
	assert nums[0] == -3
	assert nums[1] == 7
	assert nums[2] == 42
	assert nums[3] == 67
	assert nums[4] == 108
	//
	mut users := [User{22, 'Peter'}, User{20, 'Bob'}, User{25, 'Alice'}]
	users.sort(a.age < b.age)
	assert(users[0].age == 20)
	assert(users[1].age == 22)
	assert(users[2].age == 25)
	assert(users[0].name == 'Bob')
	assert(users[1].name == 'Peter')
	assert(users[2].name == 'Alice')
	//
	users.sort(a.age > b.age)
	assert(users[0].age == 25)
	assert(users[1].age == 22)
	assert(users[2].age == 20)
	//
	users.sort(a.name < b.name) // Test sorting by string fields
	//assert users.map(it.name).join(' ') == 'Alice Bob Peter'
}

fn test_f32_sort() {
	mut f := [f32(50.0), 15, 1, 79, 38, 0, 27]
	f.sort_with_compare(compare_f32)
	assert f[0] == 0.0
	assert f[1] == 1.0
	assert f[6] == 79.0
}

fn test_f64_sort() {
	mut f := [50.0, 15, 1, 79, 38, 0, 27]
	f.sort_with_compare(compare_f64)
	assert f[0] == 0.0
	assert f[1] == 1.0
	assert f[6] == 79.0
}

fn test_i64_sort() {
	mut f := [i64(50), 15, 1, 79, 38, 0, 27]
	f.sort_with_compare(compare_i64)
	assert f[0] == 0
	assert f[1] == 1
	assert f[6] == 79
}

/*
fn test_for_last() {
	numbers := [1, 2, 3, 4]
	mut s := '['
	for num in numbers {
		s += '$num'
		if !last {
			s += ', '

		}
	}
	s += ']'
	assert s == '[1, 2, 3, 4]'
}
*/


struct Foo {
mut:
	bar []int
}

fn test_in_struct() {
	mut baz := Foo{
		bar: [0, 0, 0]
	}
	baz.bar[0] += 2
	baz.bar[0]++
	assert baz.bar[0] == 3
}

fn test_bools() {
	println('test b')
	mut a := [true, false]
	a << true
	println(a)
}

fn test_push_many_self() {
    mut actual_arr := [1, 2, 3, 4]
    actual_arr << actual_arr
    expected_arr := [1, 2, 3, 4, 1, 2, 3, 4]
    assert actual_arr.len == expected_arr.len
    for i in 0..actual_arr.len {
        assert actual_arr[i] == expected_arr[i]
    }
}

fn test_for() {
	nums := [1,2,3]
	mut sum := 0
	for num in nums {
		sum += num
	}
	assert sum == 6
}

fn test_clear() {
	mut arr := [1,2,3]
	assert arr.len == 3
	arr.clear()
	assert arr.len == 0

	arr << 3
	arr << 2
	arr << 1
	arr << 0
	assert arr.len == 4
	assert arr[0] == 3
	assert arr[1] == 2
	assert arr[2] == 1
	assert arr[3] == 0

	arr.clear()
	assert arr.len == 0
}

fn test_trim() {
	mut arr := [1,2,3,4,5,6,7,8,9]
	assert arr.len == 9

	arr.trim(9)
	assert arr.len == 9
	assert arr.last() == 9

	arr.trim(7)
	assert arr.len == 7
	assert arr.last() == 7

	arr.trim(2)
	assert arr.len == 2
	assert arr.last() == 2
}

fn test_hex(){
	// array hex
	st := [byte(`V`),`L`,`A`,`N`,`G`]
	assert st.hex() == "564c414e47"
	assert st.hex().len == 10

	st1 := [byte(0x41)].repeat(100)
	assert st1.hex() == "41".repeat(100)
}

fn test_left_shift_precendence() {
	mut arr := []int{}
	arr << 1 + 1
	arr << 1 - 1
	arr << 2 / 1
	arr << 2 * 1

	assert arr[0] == 2
	assert arr[1] == 0
	assert arr[2] == 2
	assert arr[3] == 2
}

fn test_array_with_cap() {
	a4 := []int{cap:10, len:1 }
	assert a4.len == 1
	assert a4.cap == 10
	a5 := []int{len:1, cap:10}
	assert a5.len == 1
	assert a5.cap == 10
}

fn test_mutli_array_index() {
	mut a := [][]int{len:2, init: []int{len:3, init:0}}
	a[0][0] = 1
	assert '$a' == '[[1, 0, 0], [0, 0, 0]]'

	mut b := [[0].repeat(3)].repeat(2)
	b[0][0] = 1
	assert '$b' == '[[1, 0, 0], [0, 0, 0]]'
}

fn test_plus_assign_string() {
	mut a := ['']
	a[0] += 'abc'
	assert a == ['abc']
}

fn mut_arr_with_eq_in_fn(mut a []int) {
	if a == [1,2,3,4] {
		a[0] = 0
	}
	if [0,2,3,4] == a {
		a[1] = 0
	}
	if !(a != [0,0,3,4]) {
		a[2] = 0
	}
	if !([0,0,0,4] != a) {
		a[3] = 0
	}
}

fn test_mut_arr_with_eq_in_fn() {
	mut a := [1,2,3,4]
	mut_arr_with_eq_in_fn(mut a)
	assert a == [0,0,0,0]
}

fn array_in_mut(mut a []int) {
	if 1 in a {
		a[0] = 2
	}
}

fn test_array_in_mut() {
	mut a := [1,2]
	array_in_mut(mut a)
	assert a == [2,2]
}

// test array delete in function with mut argument
fn delete_nums(mut arr []int) {
	arr.delete(0)
}

fn test_array_delete_in_mut() {
	mut nums := [1, 2, 3]
	delete_nums(mut nums)
	assert nums == [2, 3]
}

// test array add in function with mut argument
fn add_nums(mut arr []int) {
	arr << 4
}

fn test_array_add_in_mut() {
	mut nums := [1, 2, 3]
	add_nums(mut nums)
	assert nums == [1, 2, 3, 4]
}

fn test_reverse_in_place() {
	mut a := [1, 2, 3, 4]
	a.reverse_in_place()
	assert a == [4, 3, 2, 1]

	mut b := ['a', 'b', 'c']
	b.reverse_in_place()
	assert b == ['c', 'b', 'a']

	mut c := [[1, 2], [3, 4], [5, 6]]
	c.reverse_in_place()
	assert c == [[5, 6], [3, 4], [1, 2]]
}

fn test_array_int_pop() {
	mut a := [1,2,3,4,5]
	assert a.len == 5
	x := a.last()
	y := a.pop()
	assert x == y
	assert a.len == 4
	z := a.pop()
	assert a.len == 3
	assert z == 4
	a.pop()
	a.pop()
	final := a.pop()
	assert final == 1
}

fn test_array_string_pop() {
	mut a := ['abc', 'def', 'xyz']
	assert a.len == 3
	assert a.pop() == 'xyz'
	assert a.pop() == 'def'
	assert a.pop() == 'abc'
	assert a.len == 0
	assert a.cap == 3
}


[direct_array_access]
fn test_direct_array_access() {
	mut a := [11,22,33,44]
	assert a[0] == 11
	assert a[2] == 33
	x := a[0]
	a[0] = 21
	a[1] += 2
	a[2] = x + 3
	a[3] -= a[1]
	assert a == [21, 24, 14, 20]
}

[direct_array_access]
fn test_direct_array_access_via_ptr() {
	mut b := [11,22,33,44]
	unsafe {
		mut a := &b
		assert a[0] == 11
		assert a[2] == 33
		x := a[0]
		a[0] = 21
		a[1] += 2
		a[2] = x + 3
		a[3] -= a[1]
		assert a == [21, 24, 14, 20]
	}
}