Re: Debouncing slow mode line constructs (was: Emacs design and architecture. How about copy-on-write?)

[Ihor Radchenko]

Dmitry Gutov <dmitry@gutov.dev> writes:

> On 21/09/2023 14:36, Ihor Radchenko wrote:
>> What about automatically debouncing slow :eval constructs in the mode
>> line? If we make sure that :eval constructs running longer than a
>> threshold do not run too frequently, it can certainly improve user
>> experience.
>
> Sounds worth looking into.
>
> Though if we just do this silently, it can hide performance problems, 
> both discouraging the mode-line authors from fixing them, and creating 
> odd behaviors (from the user's POV) when something which should change, 
> doesn't.

A warning may be displayed when this "debouncing" is activated.
This will notify the users yet not degrading performance.

> BTW, most advanced mode-lines (including smart-mode-line, which I use, 
> and is reasonably fast) use the :eval constructs pretty much everywhere.

Yup. And users often have no idea how much performance may be affected
by these "fancy" mode-lines. Leading to absence of bug reports in some
edge cases and general complaints that "Emacs is slow".

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>