trycatcher / clj-barebones-guide

Barebones guide for Clojure development using Emacs

Install Clojure

Clojure

Check if you can get a REPL at the shell using `cli-tools`. To do this follow the `Using the CLI tools` section in https://clojure.org/guides/repl/launching_a_basic_repl

Install clj-kondo to watch your back

clj-kondo

Set up Emacs for Clojure development

(setq package-archives '(("gnu" . "https://elpa.gnu.org/packages/")
                         ("melpa" . "https://melpa.org/packages/")))

(unless (package-installed-p 'use-package)
  (package-refresh-contents)
  (package-install 'use-package))
(require 'use-package)
(setq use-package-verbose t)
;; The :ensure keyword causes the package(s) to be installed automatically if not already present on your system:
(setq use-package-always-ensure t)

(use-package clojure-mode-extra-font-locking
  :ensure t
  :defer t)

(use-package paredit
  :ensure t
  :defer t
  :init
  (add-hook 'clojure-mode-hook 'enable-paredit-mode)
  (add-hook 'cider-repl-mode-hook 'enable-paredit-mode)
  (add-hook 'emacs-lisp-mode-hook 'enable-paredit-mode))

;; To add some colors to parens
(use-package rainbow-delimiters
  :ensure t
  :defer t
  :init (add-hook 'prog-mode-hook 'rainbow-delimiters-mode))

(use-package flycheck-clj-kondo
  :ensure t)

(use-package clojure-mode
  :ensure t
  :config
  (require 'flycheck-clj-kondo))

(use-package cider
  :ensure t
  :defer t
  :init
  (setq cider-repl-pop-to-buffer-on-connect t
        cider-show-error-buffer t
        cider-auto-select-error-buffer t
        cider-repl-history-file "~/.emacs.d/var/cider-history"
        cider-repl-wrap-history t
        cider-repl-history-size 100
        cider-repl-use-clojure-font-lock t
        cider-docview-fill-column 70
        cider-stacktrace-fill-column 76
        nrepl-popup-stacktraces nil
        nrepl-log-messages nil
        nrepl-hide-special-buffers t
        cider-repl-use-pretty-printing t
        cider-repl-result-prefix ";; => ")
  :config
  (add-hook 'cider-mode-hook 'eldoc-mode)
  (add-hook 'cider-repl-mode-hook 'paredit-mode)
  (add-hook 'cider-repl-mode-hook 'company-mode)
  (add-hook 'cider-mode-hook 'company-mode)
  (add-hook 'cider-mode-hook
            (local-set-key (kbd "<C-return>") 'cider-eval-defun-at-point)))

;; Aggressively indent your clojure code
(use-package aggressive-indent
  :ensure t
  :defer t
  :commands (aggressive-indent-mode)
  :config
  (add-hook 'clojure-mode-hook 'aggressive-indent-mode))

Clone a skeletal repo to test

https://github.com/trycatcher/clj-hello

Test with CIDER

CIDER

• Navigate to src/hello/core.clj.
• Start a Clojure REPL with C-c M-J

If all works as expected, you will have a working REPL. Parens away!