Ruihang Xia

Sorry for the late reply :P For `move` before the closure param list, we can match it with `ident`. But I can't figure out how to match those after `async`....

It is a good point to make the rules simple by not following the formal grammar. Wondering what others think.

I made a example poll version `read_at_aligned` in #446, please check it out :D

> Greetings @waynexia! > > It looks like your PR added a new or changed an existing dependency, and CI has failed to validate your changes. Some possible reasons this...

Thanks @glommer. To use those async methods in the "poll" context, we need to store the future somewhere (to poll the same future again). And it's hard to write down...

```rust pub fn poll_read_aligned(file: &DmaFile, pos: u64, size: usize) -> PollReadAligned { task: Pin { type Output = Result; fn poll(self: Pin, cx: &mut Context

Greeting @duarten! >Why can't you call an async function from poll_next? You can, but you can't `.await` it and you need to do something like [this](https://github.com/DataDog/glommio/pull/446#issuecomment-947790091) as "*a poll function...

Sorry for the delay! >@waynexia how do you feel about giving this a try? There is potential to limit the boilerplate here. I'd like to😉. Let me try DmaFile first...

> Does it means we need support default value which is an `expr`? > > The grammar may be like: `CREATE TABLE test(a int DEFAULT b + 1, b int...

Thanks for your reproducer @jiacai2050. Here are some investigations: Looks like the `single_distinct_to_groupby` optimizer doesn't consider the original `GROUP BY` contains expression like `a+1` or `b%2`. It copies `GROUP BY`s...