nixconfig/emacs/init.org

#+TITLE: Emacs Init File
#+AUTHOR: Daniel Ziltener

* Initialization

** Requirements

Since I am using ~cl-defun~ in this init file, I need to import ~cl-macs~.

#+begin_src emacs-lisp
  (require 'cl-macs)
#+end_src

** Personal Information

#+NAME: pers-info-table
| Name            | Mail                |
|-----------------+---------------------|
| Daniel Ziltener | dziltener@lyrion.ch |

#+begin_src emacs-lisp :var input=pers-info-table
  (let ((row (car input)))
    (setq user-full-name (cl-first row))
    (setq user-mail-address (cl-second row)))
#+end_src

For storage of passwords, I use [[https://www.passwordstore.org/][pass]]: src_emacs-lisp[]{(auth-source-pass-enable)}

** Customizations

Since this init file is version controlled, and I set all customizations
myself in =use-package= blocks, I want Emacs to use a separate file
for authorized =.dir-local= variables and similar stuff.

#+begin_src emacs-lisp
  (setq custom-file "~/.emacs.d/custom.el")
  (when (file-exists-p custom-file)
    (load custom-file))
#+end_src

** Package Manager

Most packages are being installed using =Guix=, for the few remaining ones that have to be fetched from Git, I use
[[https://github.com/progfolio/elpaca][Elpaca]].

#+begin_src emacs-lisp
(defvar elpaca-installer-version 0.6)
(defvar elpaca-directory (expand-file-name "elpaca/" user-emacs-directory))
(defvar elpaca-builds-directory (expand-file-name "builds/" elpaca-directory))
(defvar elpaca-repos-directory (expand-file-name "repos/" elpaca-directory))
(defvar elpaca-order '(elpaca :repo "https://github.com/progfolio/elpaca.git"
                              :ref nil
                              :files (:defaults "elpaca-test.el" (:exclude "extensions"))
                              :build (:not elpaca--activate-package)))
(let* ((repo  (expand-file-name "elpaca/" elpaca-repos-directory))
       (build (expand-file-name "elpaca/" elpaca-builds-directory))
       (order (cdr elpaca-order))
       (default-directory repo))
  (add-to-list 'load-path (if (file-exists-p build) build repo))
  (unless (file-exists-p repo)
    (make-directory repo t)
    (when (< emacs-major-version 28) (require 'subr-x))
    (condition-case-unless-debug err
        (if-let ((buffer (pop-to-buffer-same-window "*elpaca-bootstrap*"))
                 ((zerop (call-process "git" nil buffer t "clone"
                                       (plist-get order :repo) repo)))
                 ((zerop (call-process "git" nil buffer t "checkout"
                                       (or (plist-get order :ref) "--"))))
                 (emacs (concat invocation-directory invocation-name))
                 ((zerop (call-process emacs nil buffer nil "-Q" "-L" "." "--batch"
                                       "--eval" "(byte-recompile-directory \".\" 0 'force)")))
                 ((require 'elpaca))
                 ((elpaca-generate-autoloads "elpaca" repo)))
            (progn (message "%s" (buffer-string)) (kill-buffer buffer))
          (error "%s" (with-current-buffer buffer (buffer-string))))
      ((error) (warn "%s" err) (delete-directory repo 'recursive))))
  (unless (require 'elpaca-autoloads nil t)
    (require 'elpaca)
    (elpaca-generate-autoloads "elpaca" repo)
    (load "./elpaca-autoloads")))
(add-hook 'after-init-hook #'elpaca-process-queues)
(elpaca `(,@elpaca-order))
#+end_src

A few additional lines are necessary to integrate it with =use-package=:
#+begin_src emacs-lisp
(elpaca elpaca-use-package
        (elpaca-use-package-mode)
        (setq elpaca-use-package-by-default nil))
(elpaca-wait)
#+end_src

* Helper Functions

Those are meant to reduce code duplication, and add some basic useful features.
The first one is a function to create conditional keybindings.

#+BEGIN_SRC  emacs-lisp
  (cl-defun conditional-keybind
      "Creates a keybinding that checks `filter-fn`.  If it succeeds,
  `target-fn` is run, otherwise `fail-fn`. If no fail-fn is given,
  `self-insert-command` is run instead.
  `target-fn` and `fail-fn` must both be interactive."
    (lambda (_prefix)
      (interactive "P")
      (if (funcall filter-fn)
          (call-interactively target-fn)
        (call-interactively fail-fn))))
#+end_src

* Core Emacs Customization                                        :important:

Enabled core modes:

#+NAME: enabled-core-modes
- display-time-mode
- global-hl-line-mode
- global-prettify-symbols-mode
- recentf-mode

Disabled core modes:

#+NAME: disabled-core-modes
- indent-tabs-mode
- menu-bar-mode
- scroll-bar-mode
- tool-bar-mode

#+begin_src emacs-lisp :var enabled=enabled-core-modes :var disabled=disabled-core-modes
  (use-package emacs
    :custom
    (completion-cycle-threshold 10)
    (display-time-mode t)
    (enable-recursive-minibuffers t)
    (enable-remote-dir-locals t)
    (fill-column 100)
    (global-hl-line-mode t)
    (global-prettify-symbols-mode t)
    (indent-tabs-mode nil)
    (menu-bar-mode nil)
    (minibuffer-prompt-properties (read-only t cursor-intangible t face minibuffer-prompt))
    (read-extended-command-predicate #'command-completion-default-include-p)
    (recentf-mode t)
    (scroll-bar-mode nil)
    (tab-always-indent 'complete)
    (tool-bar-mode nil)
    :custom-face
    (default ((t (:weight bold :height 113 :width normal :family "VictorMono Nerd Font"))))
    :hook
    (minibuffer-setup . cursor-intangible-mode)
    :config
    (advice-add 'risky-local-variable-p :override #'ignore))
#+end_src

** Sending Mail