PHP XML을 배열 코드로 변환

// Xml 转 数组, 包括根键，忽略空元素和属性，尚有重大错误
function xml_to_array( $xml )
{
    $reg = "/<(\w )[^>]*?>([\x00-\xFF]*?)<\/>/";
    if(preg_match_all($reg, $xml, $matches))
    {
        $count = count($matches[0]);
        $arr = array();
        for($i = 0; $i < $count; $i  )
        {
            $key = $matches[1][$i];
            $val = xml_to_array( $matches[2][$i] );  // 递归
            if(array_key_exists($key, $arr))
            {
                if(is_array($arr[$key]))
                {
                    if(!array_key_exists(0,$arr[$key]))
                    {
                        $arr[$key] = array($arr[$key]);
                    }
                }else{
                    $arr[$key] = array($arr[$key]);
                }
                $arr[$key][] = $val;
            }else{
                $arr[$key] = $val;
            }
        }
        return $arr;
    }else{
        return $xml;
    }
}
// Xml 转 数组, 不包括根键
function xmltoarray( $xml )
{
    $arr = xml_to_array($xml);
    $key = array_keys($arr);
    return $arr[$key[0]];
}
// 类似 XPATH 的数组选择器
function xml_array_select( $arr, $arrpath )
{
    $arrpath = trim( $arrpath, '/' );
    if(!$arrpath) return $arr;
    $self = 'xml_array_select';

    $pos = strpos( $arrpath, '/' );
    $pos = $pos ? $pos : strlen($arrpath);
    $curpath = substr($arrpath, 0, $pos);
    $next = substr($arrpath, $pos);

    if(preg_match("/\[(\d )\]$/",$curpath,$predicate))
    {
        $curpath = substr($curpath, 0, strpos($curpath,"[{$predicate[1]}]"));
        $result = $arr[$curpath][$predicate[1]];
    }else $result = $arr[$curpath];

    if( is_array($arr) && !array_key_exists($curpath, $arr) )
    {
        die( 'key is not exists:' . $curpath );
    }

    return $self($result, $next);
}
// 如果输入的数组是全数字键，则将元素值依次传输到 $callback, 否则将自身传输给$callback
function xml_array_each( $arr, $callback )
{
    if(func_num_args()<2) die('parameters error');
    if(!is_array($arr)) die('parameter 1 shuld be an array!');
    if(!is_callable($callback)) die('parameter 2 shuld be an function!');
    $keys = array_keys($arr);
    $isok = true;
    foreach( $keys as $key ) {if(!is_int($key)) {$isok = false; break;}}
    if($isok)
        foreach( $arr as $val ) $result[] = $callback($val);
    else
        $result[] = $callback( $arr );
    return $result;
}
?>