Subject: Re: bug#56682: Fix the long lines font locking related slowdowns

From: Dmitry Gutov <[email-masked]>
Date: Sun, 14 Aug 2022 21:18:31 +0300

On 14.08.2022 20:54, Gregory Heytings wrote:
> 
>>> If the conclusion is, after some reasonable effort, that there is no 
>>> way to make syntax-ppss significantly faster in one way or another in 
>>> such cases, and that there is no way to make font locking reasonably 
>>> accurate even when it doesn't have access to the whole buffer, it 
>>> might make sense to provide user options to fine-tune the behavior.  
>>> But we are not there yet.
>>
>> Both conclusions lead to removing the applications of narrowing from 
>> handle_fontified_prop.
>>
> 
> I have seen no effort whatsoever to make syntax-ppss significantly 
> faster in one way or another.

syntax-ppss is limited in its performance by parse-partial-sexp.

Could you take a look at it? Seems like more of your area of expertise.