<?php
/*
 * flatter_test.php
 */

/**
 * @param string $message
 * @param callable $callback
 */
function timer(string $message, callable $callback): void
{
    $start = microtime(true);

    $callback();

    $span = microtime(true) - $start;
    echo "{$message} -> {$span} sec\n";
}

$size = 100000;
$source = [];
for ($i = 0; $i < $size; $i++) {
    $source[] = [0,1,2,3=>[4,5,6=>[7,8,9=>10,11,12=>[13,14,15=>[16,17,false,[null]]]]]];
}

/*
 * Recursive function
 */
function flatterFunction(array $source, array &$effected): void
{
    foreach ($source as $v) {
        if (is_array($v)) {
            flatterFunction($v, $effected);
        } else {
            $effected[] = $v;
        }
    }
}

timer('Recursive Function', function () use ($source) {
    $effected = [];
    flatterFunction($source, $effected);
    //echo var_export($effected, true) . PHP_EOL;
});

/*
 * Recursive Iterator
 */
timer('Recursive Iterator', function () use ($source) {
    $iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($source));
    $effected = [];
    foreach ($iterator as $v) {
        $effected[] = $v;
    }
    //echo var_export($effected, true) . PHP_EOL;
});

/*
 * Recursive Closure
 */
timer('Recursive Closure', function () use ($source) {
    $effected = [];
    array_walk_recursive($source, function($v) use (&$effected) { $effected[] = $v; });
    //echo var_export($effected, true) . PHP_EOL;
});