<?php

/**
 * Array manipulation functions
 */
class ArrayF {
    /**
     * Insert an element after another element
     * @param array Array to insert into
     * @param mixed element (value) to insert after
     * @param mixed element to insert
     * @param mixed key to insert element with
     * @result array modified array
     */
    public static function insertAfter(&$array, $after, $value, $key = null) {
        $keys = array_keys($array);
        $afterKey = array_search($after, $array, true);

        $old = $array;

        ArrayF::clear($array);

        foreach ($keys as $oldKey) {
            $array[$oldKey] = $old[$oldKey];

            if ($oldKey === $afterKey) {
                if ($key === null) {
                    $array[] = $value;
                }
                else {
                    $array[$key] = $value;
                }
            }
        }

        return $array;
    }

    /**
     * deletes all the elements
     * @param array array to delete from
     * @result array the same array, empty
     */
    public static function clear(&$array) {
        foreach ($array as $key => $value) {
            unset($array[$key]);
        }
        return $array;
    }
        
}