Emacs: found that "dired-subtree" has a toggle behaviour!
Raw link: https://www.youtube.com/watch?v=vm-FvNdYFcc
In this short video I explain how I was able to discover two
undocumented functions of dired-subtree, which define a toggle and a
cyclical behaviour for expanding or contracting a subdirectory inside of
Dired. I also discuss how to use the built-in methods of Emacs to
discover such hidden features.
And this is a link to my configuration file, with all the settings I showed in the video as well as everything else, from previous screen casts: protesilaos.com/emacs/dotemacs.