Another happy Hammerspoon user reporting.

I feel Hammerspoon's Lua is to macOS what elisp is to Emacs. You can use it to glue all sorts of wonderful things.

I wrote a bit about it here: https://xenodium.com/emacs-utilities-for-your-os (building my own Alfred/Quicksilver-like experience) and https://xenodium.com/cycling-window-layouts-via-hammerspoon (cycle through my preferred window layouts).

edit: typos