strtr 或 str_replace 在 foreach 内部运行而不会杀死服务器

我有这些对象数组，

array (
    [0] => DataCON Object (
            [id] => 2
            [first_name] => Urek
            [last_name] => Mazino
            [email] => hello@world.com
            [phone] => 000-444-5555
            [date] => 2016-02-11 14:46:38
            .
            .
            .
            .
        )
    [1] => DataCON Object (
            [ID] => 3
            .
            .
            .
            .
        )
    )

我创建了一个函数，该函数循环遍历每个对象并根据另一个函数提供的模板返回值，但问题是当我有超过 1 个对象结果时，它只会杀死服务器，我的目标是让<span class="{fname}">{ID} - {email}</span>返回<span class="Urek">2 - hello@world.com</span>

这是我的代码，

class Kill_Bill {
    .
    .
    .
    public function _get_data( $template ) {
        $object = $this->the_data_object();
        if ( !$object ) return ' to me';
        $to_her = '';
        foreach ( $object as $obj ) {
            $tags = array(
                '{id}'      => $obj->id,    
                '{fname}'   => $obj->first_name,    
                '{lname}'   => $obj->last_name,
                '{email}'   => $obj->email,
                .                       
                .   // This whole thing is killing my server with bytes exhuasted,              
                .   // it only works fine if there's a single object in an array,                   
            );                          
            $to_her .=  strtr( $template, $tags ); 
            #$to_her .= str_replace('{id}', $obj->id, $template ) // This works fine.
        }
        return $to_her;
    }
    .
    .
    .
}

是否有更好、更快的方法代替str_replace，我可以用来用对象值替换模板值？