Re: Performance degradation from long lines

[Eli Zaretskii]

> From: Phil Sainty <address@hidden>
> Cc: Eli Zaretskii <address@hidden>, mithraeum <address@hidden>,
>  Stefan Monnier <address@hidden>
> Date: Sun, 7 Jul 2019 02:18:17 +1200
> 
> I'll merge scratch/so-long to master in another week or so if there's
> no objections.
> 
> I'm keen to get additional input on some of the default config, but
> it'll be that much easier to get people to test and provide additional
> suggestions once it's been merged.

Thanks for merging this.

I made a few minor fixes to the docs.

One comment I have is that disabling bidi-display-reordering should
probably be removed from the defaults, because doing so puts the
display engine in a state that is not being tested, and can cause
inconsistencies and even bugs (because some portions of the code were
written under the assumption that this variable is never nil).

OTOH, I'd suggest setting bidi-paragraph-direction to 'left-to-right
by default when so-long-mode is turned on.

Also, I don't understand why the defaults disable
display-line-number-mode, it AFAIK does not slow down redisplay in any
significant ways.  Do you have any evidence it should be disabled in
buffers with long lines?

IME, truncate-lines sometimes makes display of long lines _faster_, so
I'm not sure we should disable that by default.