closure.php

<?php
class ActiveRecord {

    public static function find($id) {
        echo $id, PHP_EOL;
    }
}

class ActiveRecordCache {

    public static function cache($finder) {
        if($cached) {
            return $cachedResults;
        }
        return $finder();
    }
}

ActiveRecordCache::cache(function() {
    return ActiveRecord::find(1);
});

$find = function($id) {
    echo $id, PHP_EOL;
};

$find(1);

$array = array(1, 2, 3, 4, 5);
array_map(function($text) { echo $text, PHP_EOL; }, $array);
?>