Closures in PHP 5.2.

gistfile1.php

<?php

function create_closure($args, $closureMap, $code) {
    if ($closureMap) {
        $globalRand = mt_rand();
        $GLOBALS[$globalRand] = $closureMap;
        
        $code = 'extract($GLOBALS['.$globalRand.']);'.$code;
    }
    
    return create_function($args, $code);
}

$outer = 1;
$anon = create_closure('$a, $b', compact('outer'), 'return $a + $b + $outer;');
echo $anon(2, 3);