Re: Refresh display after changing variable

[Ken Goldman <kgoldman@us.ibm.com>]

On 8/2/2021 5:26 PM, 2QdxY4RzWzUUiLuE@potatochowder.com wrote:
> On 2021-08-02 at 22:56:41 +0200,
> Michael Heerdegen <michael_heerdegen@web.de> wrote:
> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>>>> From: Ken Goldman <kgoldman@us.ibm.com>
>>>> Date: Mon, 2 Aug 2021 15:36:01 -0400
>>>>
>>>>>     (defun kg-toggle-whitespace-line-column ()
>>>>>        "Toggle whitespace line column between 80 and 101"
>>>>>        (interactive)
>>>>>        (setq whitespace-line-column (if (= whitespace-line-column
>>>>> 80) 101 80))
>>>>>        (whitespace-mode 1))
> 
> FWIW, I have the following snippet in a function I wrote to change
> tab-width:
> 
>    (let ((w (get-buffer-window (current-buffer))))
>      (set-window-start w (window-start w)))
> 
> and a note that I stole that snippet from scroll-bar-maybe-window-start
> in scroll-bar.el.  That function doesn't exist anymore (in Emacs 27.2),
> but scroll-bar-set-window-start in scroll-bar.el does end as follows:
> 
>      (set-window-start window (point))))))
> 
That line, in the function, yields

kg-toggle-whitespace-line-column: Symbol’s value as variable is void: window