Re: Long lines and bidi

[Eli Zaretskii <eliz@gnu.org>]

> From: "Drew Adams" <drew.adams@oracle.com>
> Cc: <eggert@cs.ucla.edu>, <dmantipov@yandex.ru>
> Date: Mon, 11 Feb 2013 09:55:36 -0800
> 
> > Turning on the newline cache speeds up these searches for a newline by
> > a factor of 2, which is not too spectacular, but not negligible.  Any
> > objections to turning on that caching by default in all buffers?
> 
> I only followed some of all that you wrote, and I haven't followed the thread.
> But a question:
> 
> You do not mention any added cost, AFAICT (but again, I did not follow in
> detail).

The overhead is only visible with very short lines, and is negligible
even then.

> Is the caching relevant (helpful) regardless of the value of truncate-lines or
> whether visual-line-mode etc. is on?  IOW, does it make sense for many common
> configurations or just for some particular configs?

It always makes sense.  Searching for newlines is a very frequent
operation in Emacs, not only in the display engine.

> What about "for all buffers"?  Does it make sense also for buffers such as Dired
> and Info, which have relatively short line lengths?

It doesn't hurt there, AFAICS.  And we can always turn it off in the
mode function, if we find later that some modes don't like it.