Re: Stealth fontification GCs a lot

[Ralf Angeli <angeli@iwi.uni-sb.de>]

* Richard Stallman (2005-04-15) writes:

>     I don't really mind an initial fontification of the whole buffer.  A
>     worse annoyance of stealth fontification is that this happens again
>     and again after every modification of the buffer.
>
> Are you saying that stealth fontification rechecks the whole buffer
> after any change in it?

I often have that impression.  Now I actually looked at the code and
it does not refontify the whole buffer but the buffer downwards from
the position a change happened.  The doc string of
`jit-lock-after-change' explains that:

(defun jit-lock-after-change (start end old-len)
  "Mark the rest of the buffer as not fontified after a change.
Installed on `after-change-functions'.
START and END are the start and end of the changed text.  OLD-LEN
is the pre-change length.
This function ensures that lines following the change will be refontified
in case the syntax of those lines has changed.  Refontification
will take place when text is fontified stealthily."

-- 
Ralf