print dictionary without recursion

test.php

<?php

$arr = [
    "foo" => "bar",
    "baz" => [
        "bang" => "buck",
        "fuck" => [
            "a" => "duck",
            "for" => [
                "welp" => "yeap",
                "suck" => "much",
            ]
        ]
        "zomg" => "ukno"
    ],
    "orly" => "yarly",
    "fucking" => "shit",
];

$stack = [];
foreach ($arr as $key => $value) {
    $stack[] = [$key, $value];
}
$stack = array_reverse($stack);
$indent_level = 0;
while(!empty($stack)) {
    
    $top = array_pop($stack);
    if ($top === true) {
        $indent_level--;
        continue;
    } else {
        list($key, $value) = $top;
    }
    if (is_string($value)) {
        echo str_repeat("    ", $indent_level) . "$key: $value\n";
    } else {
        echo str_repeat("    ", $indent_level) . "$key:\n";
        $indent_level++;
        $sub_arr = array_reverse($value, true);
        $stack[] = true;
        foreach ($sub_arr as $key2 => $value2) {
             $stack[] = [$key2, $value2];
        } 
    }
}