<?php

/**
* @package utf8
*/

//---------------------------------------------------------------
/**
* UTF-8 aware alternative to str_split
* Convert a string to an array
* Note: requires utf8_strlen to be loaded
* @param string UTF-8 encoded
* @param int number to characters to split string by
* @return string characters in string reverses
* @see http://www.php.net/str_split
* @see utf8_strlen
* @package utf8
*/
function utf8_str_split($str, $split_len = 1)
{
    if (!preg_match('/^[0-9]+$/', $split_len) || $split_len < 1) {
        return false;
    }

    $len = utf8_strlen($str);
    if ($len <= $split_len) {
        return [$str];
    }

    preg_match_all('/.{' . $split_len . '}|[^\x00]{1,' . $split_len . '}$/us', $str, $ar);
    return $ar[0];
}
