Pick the dynamic filter from #353

[liuchengxu]

I have cherry-picked the dynamic filter code from #353, and refacotor it a bit. There are still some details to deal with, but mostly works great in Vim.

[fixed] But I notice something weired in the top results returned during the dynamic update, see 00:30~00:43 in this gif https://asciinema.org/a/FT3magg2dk6VHIVg04PYgfIpw , the top first item looks right and is seemingly stable, while the other top N items looks far from the top first one. In the end, the results looks right suddently. I'm a little confused. @ImmemorConsultrixContrarie

[ImmemorConsultrixContrarie]

But I notice something weired in the top results returned during the dynamic update, see 00:30~00:43 in this gif https://asciinema.org/a/FT3magg2dk6VHIVg04PYgfIpw , the top first item looks right and is seemingly stable, while the other top N items looks far from the top first one. In the end, the results looks right suddently. I'm a little confused.

Looks like a bug in sorting algo for temporary results. I could have done this sort wrong. Also some logic bugs could have crawled into this function or this macro.

[ImmemorConsultrixContrarie]

Yeah, it's there.
The chain should be like .iter().enumerate().rev(), but .rev() goes before the enumerate.

@liuchengxu

[liuchengxu]

Yeah, it's there.
The chain should be like .iter().enumerate().rev(), but .rev() goes before the enumerate.

Yes, that's the culprit 👍, now it looks all right.