Keeping code consistently formatted is important for readability and maintainability. Once you get used to having a computer format your code for you, manually formatting code can feel tedious.

For the last few years, my team has been using zprint to keep our Clojure codebase formatted to our specifications. zprint is great because it runs fast and is extremely customizable. This flexibility is powerful since it lets you format your code exactly how you want.

I've recently migrated from my own custom before-save-hook that triggered zprint whenever I saved a buffer to using Apheleia. Apheleia is an Emacs package that applies code formatters automatically on save. I won't quote the whole introduction in Apheleia's readme but it is designed to keep Emacs feeling responsive.

Here's the configuration I use in my Emacs setup:

(use-package apheleia
  :straight (apheleia :host github :repo "radian-software/apheleia")
  :config
  (setf (alist-get 'zprint apheleia-formatters)
        '("zprint" "{:style [:community] :map {:comma? false}}"))
  (setf (alist-get 'clojure-mode apheleia-mode-alist) 'zprint
        (alist-get 'clojure-ts-mode apheleia-mode-alist) 'zprint)
  (apheleia-global-mode t))

This snippet shows how to install and configure using straight.el and use-package. The :config section instructs apheleia under what modes it should run zprint and how to run it.¹ I found the docstring for apheleia-formatters to be crucial for figuring out how to hook zprint into apheleia.

With this setup, your Clojure code will be automatically formatted using zprint every time you save. No more manual formatting needed. I've been running with this for a little while now and am enjoying it.

1. I don't actually use :community and have my own custom formatting configuration but am using :community in this post so the snippet is immediately useful to readers.↩