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

[Ihor Radchenko]

Eli Zaretskii <eliz@gnu.org> writes:

>> redisplay optimizations may decide to not refresh the mode-line when
>> typing.
>
> If they do, it's a bug.

You are right. Typing appears to trigger mode-line redisplay.
What I thought is a redisplay optimization is different - `vc-mode'
variable used to display VC status is not updated on every redisplay.
Instead, it is modified when visiting a file and when saving a file.
The end result is the same - VC status is not always up-to-date.

Similar approach is often used by other well-optimized mode-line
constructs, leading to sometimes-outdated mode-line.

-- 
Ihor Radchenko // yantar92,
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