Re: How to detect words being added and removed to a buffer in a minor mode?

[Bob Newell <bobnewell@bobnewell.net>]

This might provide some of what you want although perhaps not all.

https://github.com/emacsmirror/nanowrimo



On Sat, Nov 19, 2022, 10:46 Pravles Redneсkoff via Users list for the GNU
Emacs text editor <help-gnu-emacs@gnu.org> wrote:

> Hello!
>
> I want to create a minor mode which allows you to see the number of words
> in a buffer.
>
> I want it to work in the following way:
>
> 1. User enters "M-x pwc-set-counter" and sets the word counter to a
> particular number.
> 2. Whenever a word is added to a buffer, the word counter is incremented.
> 3. Whenever a word is removed from a buffer, the word counter is
> decremented.
> 4. As long as the minor mode is active, the value of the word counter is
> visible in the mode line (same place where current row and column are shown
> in some modes).
>
> Restrictions:
>
> 1. This minor mode should work for text (Org mode) buffers with up to 3000
> words (i. e. we are NOT talking gigabytes of text).
> 2. This minor mode must be compatible with the evil and Org mode.
>
> How is the minor mode I want to develop different from existing solutions?
>
> I want to be able to count words that I wrote on a particular day.
>
> Imagine I have a goal of writing at least 1000 words per day. When I begin
> to write on a new day, I reset the word counter to zero. Then I write in
> one buffer and see the progress in the modeline. Then I may switch to a
> different buffer (a different chapter), manually change the word counter
> and continue to work.
>
> What I want to implement is the word counter from Scrivener which shows
> you the number of words you wrote today across different chapters. It also
> shows you a visual representatio of the percentage of the daily quota.
>
> As far as I know, none of the existing Emacs word counters offers this
> functionality.
>
> Questions:
>
> 1. How can I create an "event listener" (sorry for the non-Emacsian
> terminology) which would be called whenever the user types something in the
> buffer?
> 2. Are there existing functions that count the words in the current buffer
> which I can reuse in my minor mode?
>
> Thanks in advance
>
> Pravles