Re: CC Mode -> Tree sitter challenge

[Theodor Thornhill]

On 6 November 2022 02:13:14 CET, Yuan Fu <casouri@gmail.com> wrote:
>
>
>> On Nov 5, 2022, at 9:38 AM, Theodor Thornhill <theo@thornhill.no> wrote:
>> 
>> 
>> Hi again, Eli!
>> 
>>>> 
>>>> Interesting. My guess is that there are still some improvement possible in 
>>>> the indent-region code, considering that part of treesit.el is quite new.
>>>> 
>>>> What do you think, Yuan? Any thoughts?
>>>> 
>>>> Anyways, I'll keep working on this and see how far I get next coming 
>>>> weeks. At least in performance it seems I have a good thing going here :-)
>>>> 
>>> 
>>> Thinking of it, some of the indentation questions isn't compiled. I'll run 
>>> it again later when they are compiled as well :-)
>>> 
>> 
>> Yes, that was the issue.  Now the scores are as follows:
>
>The indentation code has a list of rules, and it runs each rule top-to-bottom 
>until one rules matches, then it uses that rule to determine how much to 
>indent. The ordering of each rule could be tweaked so that most frequent case 
>comes forward. We can also arrange these rules not linearly but in a tree, so 
>if one rules matches/doesn’t match, some other rules can be skipped.

I think the system as it is now it fine, at least for the time being. But I 
hold no strong opinions there :)

>
>What exactly did you compile? I tried byte-compiling indentation rules before 
>but didn’t see a significant speed-up.
>
>Yuan

See https://git.sr.ht/~theo/tree-sitter-modes/tree/master/item/c-ts-mode.el#L92

Sometimes when exploring indentation i use rules like this. Usually I try to 
find other ways after, but I just assumed they weren't perf problems. 
Apparently they are!

And by the way, i created an anchor like this: 
https://git.sr.ht/~theo/tree-sitter-modes/tree/master/item/c-ts-mode.el#L57

This is nice when you need to just move a token to col 0, such as 
preproc-directives. Maybe that should be a standard one? It could use the 
buffer-root-node, but this was so simple and fast that I just did it like that.

What do you think?

Theo