Re: Any expert on font-lock machinery able to provide some insight

[Eli Zaretskii <eliz@gnu.org>]

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> Date: Fri, 3 Jan 2025 13:44:04 +0100
> From: Harald Kirsch <pifpafpuf@gmx.de>
> 
> Hi Eli,
> 
> thanks for the explanation.
> 
> On 03.01.25 12:58, Eli Zaretskii wrote:
> ...
> >> But it seems I am missing another channel of information which triggers
> >> font-locking too often.
> >
> > Why does it bother you that it happens too often?
> 
> 1. I compare with elisp font-locking which is much less frequent.
> 
> 2. It is eglot-semtok, which does an LSP server call to get font-lock
> information. It is quick enough and I wouldn't have noticed without the
> logging, but it seems a waste nevertheless.
> 
> >> With describe-char I do see
> >>
> >> There are text properties here:
> >>     fontified            defer
> >>
> >> not going away. Can this point to the problem?
> >
> > This should only happen with buffer positions that were not yet
> > fontified.  If the buffer position was already fontified, the value
> > should be t.
> 
> The buffer position was already fontified, so I should not see this. I
> might be doing something wrong so that the font-lock machinery thinks,
> font-locking did not happen. The actual fontification happens
> asynchronously (due to the server roundtrip), but I thought I had given
> the engine enough info pretending all is done. I don't fully understand,
> how the decision is made to fontify again.
> 
> Cheers
> Harald
>