Proposal: Refactor Middleware Execution / Next with Cursors and Async Recursion #896

    /// Call next handler. If get next handler and executed, returns true, otherwise returns false.
    ///
    /// If resposne's statuse code is error or is redirection, all reset handlers will skipped.
    #[inline]
    #[async_recursion]
    pub async fn call_next(&mut self, req: &mut Request, depot: &mut Depot, res: &mut Response) -> bool {
        if let Some(code) = res.status_code() {
            if code.is_client_error() || code.is_server_error() || code.is_redirection() {
                self.skip_rest();
                return false;
            }
        }
        if let Some(handler) = self.handlers.get(self.cursor) {
            self.cursor += 1;
            handler.clone().handle(req, depot, res, self).await;
            if self.has_next() {
                self.call_next(req, depot, res).await;
            }
            true
        } else {
            false
        }
    }