Re: treesitter local parser: huge slowdown and memory usage in a long file

[Dmitry Gutov <dmitry@gutov.dev>]

On 12/02/2024 06:16, Yuan Fu wrote:
> Thanks, the culprit is the call to treesit-update-ranges in
> treesit--pre-redisplay, where we don’t pass it any specific range, so it
>   updates the range for the whole buffer. Eli, is there any way to get a
> rough estimate the range that redisplay is refreshing? Do you think
> something like this would work?

If we don't update the ranges outside of some interval surrounding the 
window, what does that mean for correctness?

Perhaps the mode has a syntax-propertize-function which behaves 
differently (as it should) depending on the language at point. Or 
different ranges have different syntax tables, something like that.

If the ranges, after some edit (perhaps a programmatic one, performed 
far from the visible area), are kept not update somewhere around the 
beginning of the buffer, do we not risk confusing the syntax-ppss 
parser, for example?

Come to think of it, take treesit-indent: it only updates the ranges for 
the current line. But the line's indentation usually depends on the 
previous buffer positions, doesn't it?