Re: CC Mode -> Tree sitter challenge

[Theodor Thornhill <theo@thornhill.no>]

On 6 November 2022 02:13:14 CET, Yuan Fu <casouri@gmail.com> wrote:
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>
>> On Nov 5, 2022, at 9:38 AM, Theodor Thornhill <theo@thornhill.no> wrote:
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>> 
>> 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:
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>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 :)

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