[beginner] [tutorial] Fine control over invisible char (especially 'hard space' / 'non breakable space')

Hi people, I share my beginner journey to 'how does this whitespace mode works ? I JUST WANT NON BREAKABLE SPACE TO BE DISPLAYED' (yes, I was yelling because it took me too much time for such a simple ask) &#x200B; I will only use [https://www.emacswiki.org/emacs/WhiteSpace](https://www.emacswiki.org/emacs/WhiteSpace) # What I wanted : Just display invisible char in visible way. # Why so frustrating ? Because I comes from vim, and was used to : `:set listchars=nbsp:·,tab:▸␣` (see example at [https://linuxhint.com/show-hidden-invisible-characters-vim/](https://linuxhint.com/show-hidden-invisible-characters-vim/) ) and "voilà" # The conf (custom-set-faces! ; this function comes from doom emacs, don't know the emacs way '(whitespace-hspace :foreground "#FF0000" :background "#FFFFFF") ; hard space, non breakable space, used with whitespace.el '(whitespace-tab :foreground "#FFFFFF" :background "#000000") ; tab face ) (setq whitespace-style '(face tabs spaces trailing space-before-tab indentation empty space-after-tab tab-mark space-mark) whitespace-display-mappings '((space-mark ?\ [? ] [? ]) ; space see here < > (space-mark ?\xA0 [?\xA4] [?_]) ; hardspace see here < > (tab-mark ?\t [187 9] [92 9]) ; tab see here < > (newline-mark ?\n [?\xB6 ?\n] [?$ ?\n]); end-of-line <no demo> )) (global-whitespace-mode) # The result Before : [no whitespace mode and not configured. See nothing](https://preview.redd.it/gqttunrlbef81.png?width=629&format=png&auto=webp&s=92dbea58b3052a8ea560f02b5bedf608e886bf1a) &#x200B; The default whitespace-style setup is : whitespace-style '(face tabs spaces trailing lines space-before-tab newline indentation empty space-after-tab space-mark tab-mark newline-mark missing-newline-at-eof) which display a very ugly document (unless doom emacs change it a bit) : [All those dot makes code unreadable for me, also hard space not displayed properly](https://preview.redd.it/lyxtfloqbef81.png?width=825&format=png&auto=webp&s=12c87530e207f64c712da070f336c56e713b8641) With the new configuration : [At least I can see non breakable spaces !!](https://preview.redd.it/vonfoa1wbef81.png?width=638&format=png&auto=webp&s=e2ccfbb0d81437304c2245155654d25c6302ceb4) # Notes I'm a beginner, be careful with this code as it might be not 'emacs way'. It was hard for me to understand that "whitespace-style" tell to emacs whether to display a custom face and / or a custom char mapping AND that you have to both set the face and the mapping (and disable / reenable mode after tweaking some variables). I learn that non breakable space is named hard space in emacs. But now, it's **better than vim** (of course) since I have full control. Full control gives ugly things : (setq whitespace-display-mappings '((space-mark ?e [?💖] [?_])) ) ==> [Something VERY ugly](https://preview.redd.it/odwjtjr5def81.png?width=657&format=png&auto=webp&s=bb1814ad1a4f4073e051d5c0464a3ce5f0801ad6)

I hadn't considered this before. Super helpful, thanks for sharing!

You might want to use library [`highlight-chars.el`](https://www.emacswiki.org/emacs/download/highlight-chars.el). Description [here](https://www.emacswiki.org/emacs/ShowWhiteSpace#HighlightChars). It gives you more flexibility for highlighting chars individually (or by range, etc.).