public function setIgnorePatterns($ignorePatterns)
    {
        $this->_ignorePatterns = array();
        $token                 = ' ,;';
        $pattern               = strtok($ignorePatterns, $token);

        while ($pattern !== false) {
            $this->_ignorePatterns[] = $pattern;
            $pattern                 = strtok($token);
        }

    }