emacs + clojure-mode: add multiple hooks - emacs

Question

This is a part of my init.el file, which enables one hook to the clojure-mode:
(use-package clojure-mode
:ensure t
:config (add-hook 'clojure-mode-hook #'aggressive-indent-mode))
What is the syntax for enabling multiple hooks (e.g. #'paredit-mode and maybe more)?

Answer 1

As #ArthurUlfeldt points out, you can add multiple add-hook statements, one for each of the hook functions you want to add. However, this can become a little tiresome when you have a common set of things you want to add to multiple modes.
For example, if you use a number of lisp like languages, then you might want to add paredit, aggressive-indent, eldoc, rainbow-delimiters etc to each of these modes. Rather than having to sprinkle lots of add-hook commands all through your init file, you can define your own function i.e. my-lisp-hook which calls all the init functions you were adding with individual add-hook commands. Then you just need to do an add-hook which calls your function.
The other advantage this can have is it makes adding/removing something like a new minor mode much easier. For example, if you had
(defun my-lisp-hook ()
(paredit-mode 1)
(aggressive-indent-mode 1)
(raindbow-delimiter-mode 1))
and then had
(add-hook 'emacs-lisp-mode-hook 'my-lisp-hook)
(add-hook 'lisp-mode-hook 'my-lisp-hook)
(add-hook 'clojure-mode-hook 'my-lisp-hook)
(add-hook 'cider-mode-hook 'my-lisp-hook)
and then after an ELPA package update found the new version of aggressive-indent-mode was causing problems, you could just comment out 1 line in your my-lisp-hook function to stop the call to aggressive-indent-mode and get back to work. On the other hand, if you had added it separately in each mode hook, you would hve to comment out 4 lines. It also keep things consistent. I have run into subtle issues when I've loaded minor modes in one order for one mode and a different order for a different mode. With the use of your own hook function to load common setup requirements, it all happens consistently.
Note that the above code is pseudo code and is not meant to actually run. I don't know if the command to turn on rainbow delimiters is rainbow-delimiters-mode 1 or if the right hook to use for lisp mode is lisp-mode-hook. My examples are merely done to demonstrate the concept.
the way you write your emacs init file is a personal choice, but I think you should apply the same sort of rules we all know should be applied to writing code. Two of which are 'do not repreat yourself' and 'write your code to be clear rather than clever'. I think we shold apply the same logic to our emacs init file.
I also think your off to a great start with use-package. I've just switched to using it and think it is a great way to help structure your init file. However, to get the most out of it, especially with respect to delayed loading of packages so that my startup time is reduced, I did find I had to restructure my init file a fair bit. This could simply be a sign my original structure wasn't that good or it could be a sign of my current interest in trying and tweaking my emacs config as a bit of a hobby/distraction from cutting real code, whih tends to result in a less structure init due to the constant change.

Answer 2

you can add multiple statements after the :config keyword:
(use-package clojure-mode
:ensure t
:config (add-hook 'clojure-mode-hook #'aggressive-indent-mode)
(add-hook 'clojure-mode-hook #'other-thing-here)
(yas-global-mode 1))
Here's a chunk from my config:
(use-package cider
:ensure t
:config
(define-key cider-mode-map (kbd "C-c SPC") 'avy-goto-word-1)
(define-key cider-mode-map (kbd "C-x SPC") 'avy-pop-mark))