From: Stefan Monnier <monnier@iro.umontreal.ca>
To: "Tobias C. Rittweiler" <tcr@freebits.de>
Cc: emacs-devel@gnu.org
Subject: Re: `font-lock-extend-region-functions' vs. `font-lock-extend-after-change-region-function'
Date: Wed, 29 Apr 2009 09:46:51 -0400 [thread overview]
Message-ID: <jwvfxfrwplp.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <873abr211r.fsf@freebits.de> (Tobias C. Rittweiler's message of "Wed, 29 Apr 2009 12:42:56 +0200")
> But the new region that EXTEND is called with begins at 523, and not 701
> even though we processed the region between 523 and 701 already.
> This seems more inefficient than it needs to be if I'm not missing
> anything.
You're not missing anything. It's an inefficiency in jit-lock, indeed.
jit-lock asks font-lock to highlight 1-523 and font-lock has no way to
tell jit-lock that the first call already highlighted 1-701, so next
time jit-lock needs highlighting it will do 523-1034 because it doesn't
know that 523-701 was done already.
It gets worse in the other direction: if jit-lock asks font-lock to
fontify 1000-1500 and font-lock decids to highlight 500-1600, the part
between 500-1000 will not be redisplayed (i.e. the display will only
take into account the highlighting applied by font-lock next time it
gets refreshed, which usually means at the next command).
Stefan
next prev parent reply other threads:[~2009-04-29 13:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-28 15:34 `font-lock-extend-region-functions' vs. `font-lock-extend-after-change-region-function' Tobias C. Rittweiler
2009-04-28 16:10 ` Stefan Monnier
2009-04-28 20:45 ` Tobias C. Rittweiler
2009-04-29 10:42 ` Tobias C. Rittweiler
2009-04-29 13:46 ` Stefan Monnier [this message]
2009-04-29 17:40 ` Tobias C. Rittweiler
2009-04-29 20:26 ` Stefan Monnier
2009-04-29 20:45 ` Samuel Bronson
2009-04-29 20:53 ` Stefan Monnier
2009-05-01 16:37 ` Tobias C. Rittweiler
2009-05-04 19:08 ` Stefan Monnier
2009-05-07 12:30 ` Tobias C. Rittweiler
2009-05-16 12:26 ` Tobias C. Rittweiler
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