gistfile1.php

<?php
header('Content-Type: text-plain');

$value_compare_func = function ($a, $b) {
  var_dump('a=' . $a. '; b=' . $b);
	
	if (strpos($b, '/') === 0) {
		return preg_match($b, $a) > 0 ? 0 : -1;
	}
	
	if ($a == $b) {
		$weight = 0;
	} else if ($a > $b) {
		$weight = 1;
	} else {
		$weight = -1;
	}
	
	var_dump('literal comparison: ' . $weight);
	
	return $weight;
};

$foo = ['aab' => '', 'bbb' => '', 'ccb' => '', 'abb' => ''];
$bar = ['/[a-z]b[a-z]/' => ''];
$buz = ['/c[a-z][a-z]/' => ''];


echo PHP_EOL . 'array_intersect_ukey' . PHP_EOL . PHP_EOL;

$subject = array_intersect_ukey ($foo, $bar, $buz, $value_compare_func);

echo PHP_EOL;

var_dump($subject);

echo PHP_EOL . '_array_intersect_ukey' . PHP_EOL . PHP_EOL;

$subject = _array_intersect_ukey($foo, $bar, $buz, $value_compare_func);

echo PHP_EOL;

var_dump($subject);

/**
 * @author Gajus Kuizinas <gk@anuary.com>
 * @version 1.0.0 (2013 09 30)
 */
function _array_intersect_ukey (array $arr1, array $arr2, $value_compare_func) {
	$arr_matched = [];
	$arr_unmatched = [];
	
	$args = func_get_args();
	
	$value_compare_func = end($args);
	
	foreach ($arr1 as $k1 => $v1) {
		foreach ($arr2 as $k2 => $v2) {
			$diff = $value_compare_func($k1, $k2);
		
			//var_dump('k1=' . $k1 . ', k2=' . $k2 . ', diff=' . $diff);
			
			if ($diff === 0) {
				$arr_matched[$k1] = $v1;
			} else {
				$arr_unmatched[$k1] = $v1;
			}
		}
	}
	
	if (count($args) <= 3) {
		return $arr_matched;
	}
	
	array_splice($args, 0, 2, [$arr_unmatched]);
	
	return array_merge($arr_matched, call_user_func_array('_array_intersect_ukey', $args));
}