Re: 27.0.50: How can I test a buffer-local window-configuration-change-hook in batch mode?

[Stefan Monnier]

>> It's virtually impossible to determine reliably when it's better to use
>> so-long and when it's better not to.  So theory is not super relevant
>> compared to actual practical experience.
> Agreed.  My point is that whatever the decision, I don't think I
> understand (or agree) with it being different for displayed and
> non-displayed buffers, for reasons I explained.

Most of the slowdown is linked to code related to the display, in
my experience.

And if you look at the three functions you mention:
- next-line is very rarely called as a function (C-h f suggests to
  use forward-line instead in Lisp code), so it's virtually never
  used in non-displayed buffers.
- posn-at-point doesn't return useful information AFAICT in
  non-displayed buffers.
- for vertical-motion it's not as clear, but a quick grep suggests that
  it's also rather unusual to call it in a non-displayed buffer.


        Stefan