#+title: Emacs Configuration

* Variables

Font definitions.
#+begin_src emacs-lisp
  (defvar jj/mono-font)
  (defvar jj/var-font)
#+end_src

* Functions

** Early Setup
=jj/force-custom-file= forces the use of a =custom.el= file instead of appending to =init.el=.
#+begin_src emacs-lisp
  (defun jj/force-custom-file ()
    "Use a custom file: custom.el. Load that file if it exists."
    (setq custom-file (concat user-emacs-directory "custom.el"))
    (when (file-exists-p custom-file)
      (load custom-file)))
#+end_src

=jj/set-exec-path-from-shell-PATH= make Emacs use the correct =PATH= variable as macOS fails to load the =PATH= variable from my login shell.
#+begin_src emacs-lisp
  (defun jj/set-exec-path-from-shell-PATH ()
    "Load the login shell's PATH variable manually because macOS doesn't behave well."
    (interactive)
    (let ((path-from-shell (replace-regexp-in-string
                            "[ \t\n]*$" "" (shell-command-to-string
                                            "$SHELL --login -c 'echo $PATH'"))))
      (setenv "PATH" path-from-shell)
      (setq exec-path (split-string path-from-shell path-separator))))
#+end_src

=jj/suppress-nativecomp-errors= suppresses native compilation warnings and errors. Native compilation seems to be a little broken on macOS and the warnings are just annoying.
#+begin_src emacs-lisp :tangle yes
  (defun jj/suppress-nativecomp-errors ()
    "Log errors and warnings, but don't show them on screen."
    (setq native-comp-async-report-warnings-errors 'silent))
#+end_src

=jj/setup-package-management= bootstraps package management. I use =straight= with =use-package= to allow declarative package management and include =git= repositories in addition to =elpa= / =melpa=.
#+begin_src emacs-lisp
  (defun jj/setup-package-management ()
    "Use straight with use-package for package management"
    (defvar bootstrap-version)
    (let ((bootstrap-file
           (expand-file-name
            "straight/repos/straight.el/bootstrap.el"
            (or (bound-and-true-p straight-base-dir)
                user-emacs-directory)))
          (bootstrap-version 7))
      (unless (file-exists-p bootstrap-file)
        (with-current-buffer
            (url-retrieve-synchronously
             "https://raw.githubusercontent.com/radian-software/straight.el/develop/install.el"
             'silent 'inhibit-cookies)
          (goto-char (point-max))
          (eval-print-last-sexp)))
      (load bootstrap-file nil ':nomessage))
    (straight-use-package 'use-package)
    (setq straight-use-package-by-default t))
#+end_src

Run the early setup right away.
#+begin_src emacs-lisp
  (jj/force-custom-file)
  (jj/set-exec-path-from-shell-PATH)
  (jj/suppress-nativecomp-errors)
  (jj/setup-package-management)
#+end_src

** Appearance

=jj/setup-fonts= sets up fonts. I use Source Code Pro (Nerd Font) for monospace and Computer Modern for variable width.
#+begin_src emacs-lisp
  (defun jj/setup-fonts ()
    "Set font sizes based on the operating system. macOS expects bigger fonts than Linux"
    (pcase system-type
      (`gnu/linux
       (setq jj/mono-font "SauceCodePro Nerd Font-11"
             jj/var-font "CMU Serif-14"))
      (`darwin
       (setq jj/mono-font "SauceCodePro Nerd Font-14:weight=thin"
             jj/var-font "CMU Serif-18")))
    (add-to-list 'default-frame-alist
                 `(font . ,jj/mono-font))
    (custom-set-faces
     `(variable-pitch ((t :font ,jj/var-font)))
     `(fixed-pitch ((t :font ,jj/mono-font)))))
 #+end_src

=jj/setup-theme= is the reason I use =straight= rather than just =use-package=. I have a custom Emacs theme that comes from my own fork of =doom-themes=. I also use =doom-modeline= and =nerd-icons= for a nicer-looking user interface and remove the title bar from the window along with any other unnecessary elements from the screen. =dired= is modified to use =nerd-icons= and colours.
#+begin_src emacs-lisp
  (defun jj/setup-theme ()
    "Install theming for Emacs from my fork of the doom-themes repo"
    (use-package doom-themes
      :straight
      (doom-themes :type git
                   :host github
                   :repo "doomemacs/themes"
                   :fork
                   (:host github
                    :repo "JacobJanzen/emacs-doom-themes"))
      :config
      (setq doom-themes-enable-bold t
            doom-themes-enable-italic t)
      (load-theme 'doom-pink t)
      (doom-themes-org-config))
    (use-package doom-modeline
      :init
      (doom-modeline-mode 1))
    (use-package nerd-icons)
    (use-package nerd-icons-dired
      :after
      (nerd-icons)
      :hook
      (dired-mode . nerd-icons-dired-mode))
    (use-package nerd-icons-completion
      :config
      (nerd-icons-completion-mode))
    (use-package diredfl
      :init
      (diredfl-global-mode 1))
    (add-to-list 'default-frame-alist '(undecorated . t))
    (scroll-bar-mode -1)
    (tool-bar-mode -1)
    (menu-bar-mode -1))
#+end_src

=jj/clean-startup-screen= disables the default startup screen so Emacs starts in the =scratch= buffer and also defaults to an empty =scratch= buffer.
#+begin_src emacs-lisp
  (defun jj/clean-startup-screen ()
    "Remove default startup screen; clean scratch buffer"
    (setq inhibit-startup-screen t
          initial-scratch-message nil))
#+end_src

=jj/enable-line-numbers= tells Emacs to use line numbers by default.
#+begin_src emacs-lisp
  (defun jj/enable-line-numbers ()
    "Enable line numbers by default"
    (global-display-line-numbers-mode 1))
#+end_src

=jj/setup-whitespace= configures Emacs to default to spaces over tabs and use a width of 4 by default.
#+begin_src emacs-lisp
  (defun jj/setup-whitespace ()
    (setq-default indent-tabs-mode nil)
    (setq tab-width 4
          c-basic-offset tab-width))
#+end_src

=jj/setup-visual-fill-column= installs and configures =visual-fill-column= to make some file types display with a narrow window centred in the frame.
#+begin_src emacs-lisp
  (defun jj/setup-visual-fill-column ()
    "configure and install visual-fill-column"
    (defun jj/run-visual-line-mode ()
      "run visual-line-mode"
      (visual-line-mode)
      (visual-fill-column-mode)
      (setq visual-fill-column-width 100
            visual-fill-column-center-text t))
    (use-package visual-fill-column
      :hook
      (org-mode . jj/run-visual-line-mode)
      (markdown-mode . jj/run-visual-line-mode)
      :config
      (setq visual-fill-column-width 100
            visual-fill-column-center-text t)))
#+end_src

=jj/appearance= runs all appearance functions.
#+begin_src emacs-lisp
  (defun jj/appearance ()
    "Run appearance functions"
    (jj/setup-fonts)
    (jj/setup-theme)
    (jj/clean-startup-screen)
    (jj/enable-line-numbers)
    (jj/setup-whitespace)
    (jj/setup-visual-fill-column))

#+end_src

** Behaviour

=jj/nicer-scroll= makes Emacs scroll one line at a time instead of big jumps.
#+begin_src emacs-lisp
  (defun jj/nicer-scroll ()
    "Scroll one line at a time"
    (setq scroll-conservatively most-positive-fixnum))
#+end_src

=jj/setup-delete-trailing-whitespace= make Emacs delete trailing whitspace on save. This does not happen in =markdown-mode= which sometimes needs trailing whitespace.
#+begin_src emacs-lisp
  (defun jj/setup-delete-trailing-whitespace ()
    "Delete trailing whitespace on save"
    (add-hook 'before-save-hook
              (lambda ()
                (unless (eql (with-current-buffer (current-buffer) major-mode)
                             'markdown-mode)
                  (delete-trailing-whitespace)))))
#+end_src

=jj/setup-auto-make-directory= makes Emacs create directories if they don't exist if the user selects that answer.
#+begin_src emacs-lisp
  (defun jj/setup-auto-make-directory ()
    (add-to-list 'find-file-not-found-functions
                 (lambda ()
                   (let ((parent-directory (file-name-directory buffer-file-name)))
                     (when (and (not (file-exists-p parent-directory))
                                (y-or-n-p (format "Directory `%s' does not exist! Create it?" parent-directory)))
                       (make-directory parent-directory t))))))
#+end_src

=jj/setup-disable-backup-files= disables the creation of backup files which pollute the file system.
#+begin_src emacs-lisp
  (defun jj/setup-disable-backup-files ()
    "disable creation of backup files"
    (setq make-backup-files nil))
#+end_src

=jj/save-place-in-pdf= makes PDFs save where in the document it was last.
#+begin_src emacs-lisp
  (defun jj/save-place-in-pdf ()
    "keep position in PDF files"
    (use-package saveplace-pdf-view
      :config
      (save-place-mode 1)))
#+end_src

=jj/behaviour= runs all behaviour setup functions.
#+begin_src emacs-lisp :tangle yes
  (defun jj/behaviour ()
    "Setup behaviour for Emacs"
    (jj/nicer-scroll)
    (jj/setup-delete-trailing-whitespace)
    (jj/setup-auto-make-directory)
    (jj/setup-disable-backup-files)
    (jj/save-place-in-pdf))
#+end_src

** Tools

=jj/setup-dumb-jump= configures =dumb-jump= for better lookup.
#+begin_src emacs-lisp
  (defun jj/setup-dumb-jump ()
    "install and configure dumb-jump"
    (use-package dumb-jump
      :init (add-hook 'xref-backend-functions #'dumb-jump-xref-activate)))
#+end_src

=jj/setup-magit= configures and installs =magit= as a =git= front end.
#+begin_src emacs-lisp
  (defun jj/setup-magit ()
    "install magit"
    (use-package magit))
#+end_src

=jj/setup-pdf-tools= installs a better PDF viewer than =DocView=.
#+begin_src emacs-lisp
  (defun jj/setup-pdf-tools ()
    "install pdf-tools"
    (use-package pdf-tools
      :config
      (pdf-tools-install)
      :hook
      (pdf-view-mode . (lambda () (display-line-numbers-mode -1)))
      :init
      (add-hook 'TeX-after-compilation-finished-functions #'TeX-revert-document-buffer)
      :config
      (setq TeX-view-program-selection '((output-pdf "PDF Tools"))
            TeX-view-program-list '(("PDF Tools" Tex-pdf-tools-sync-view))
            TeX-source-correlate-start-server t)))
#+end_src

=jj/setup-fzf= installs and configures =fzf= to be used as a fuzzy finder.
#+begin_src emacs-lisp
  (defun jj/setup-fzf ()
    "install and configure fzf"
    (use-package fzf
      :bind
      ("C-c C-f" . fzf)
      :config
      (setq fzf/args "-x --color 16 --print-query --margin=1,0 --no-hscroll"
            fzf/executable "fzf"
            fzf/git-grep-args "-i --line-number %s"
            fzf/grep-command "grep -nrH"
            fzf/position-bottom nil
            fzf/window-height 15)))
#+end_src

=jj/setup-vterm= configures and installs =vterm= as a terminal emulator in Emacs.
#+begin_src emacs-lisp
  (defun jj/setup-vterm ()
    "install and configure vterm"
    (use-package vterm
      :bind
      ("C-c v" . vterm)))
#+end_src

=jj/setup-completions= installs =company= for completions. It is configured to start with no delay immediately after the first key press. =vertico= is used as a front end for completions. =orderless= is used to allow searching in any portion of a string and =marginalia= gives descriptions of items in the list.
#+begin_src emacs-lisp
  (defun jj/setup-completions ()
    "configure and install company"
    (use-package company
      :config
      (add-hook 'after-init-hook 'global-company-mode)
      (setq company-idle-delay 0
            company-minimum-prefix-length 1
            company-selection-wrap-around t))
    (use-package vertico
      :custom
      (vertico-cycle t)
      :init
      (vertico-mode 1))
    (use-package orderless
      :custom
      (completion-styles '(orderless basic))
      (completion-category-overrides '((file (styles basic partial-completion)))))
    (use-package marginalia
      :bind
      (:map minibuffer-local-map
            ("M-A" . marginalia-cycle))
      :init
      (marginalia-mode 1)))
#+end_src

=jj/setup-checkers= sets up =flycheck= and =flyspell= for syntax and spell checking respectively.
#+begin_src emacs-lisp
  (defun jj/setup-checkers ()
    "Configure and install flycheck and flyspell"
    (use-package flycheck
      :config
      (add-hook 'after-init-hook #'global-flycheck-mode))
    (use-package flyspell
      :hook
      (text-mode . flyspell-mode))
    (use-package flyspell-correct
      :after flyspell
      :bind (:map flyspell-mode-map ("C-;" . flyspell-correct-wrapper))))
#+end_src

=jj/setup-snippets= installs =yasnippet= for managing snippets and =yasnippet-snippets= for a collection of useful snippets.
#+begin_src emacs-lisp
  (defun jj/setup-snippets ()
    "install snippets"
    (use-package yasnippet
      :init
      (yas-global-mode 1)
      :bind
      ("C-c s" . yas-insert-snippet))
    (use-package yasnippet-snippets))
#+end_src

=jj/setup-formatting= installs =apheleia= and =clang-format= to automatically format code on save.
#+begin_src emacs-lisp
  (defun jj/setup-formatting ()
    "setup auto-formatters"
    (use-package apheleia
      :init (apheleia-global-mode 1))
    (use-package clang-format))
#+end_src

=jj/setup-rss= configures and installs =elfeed= to serve as an =rss= feed reader. It stores the feed [[./feed.org.org][here]].
#+begin_src emacs-lisp
  (defun jj/setup-rss ()
    "configure elfeed for rss"
    (use-package elfeed
      :bind
      ("C-c e f" . elfeed)
      ("C-c e u" . elfeed-update))
    (use-package elfeed-goodies
      :after
      elfeed
      :config
      (elfeed-goodies/setup))
    (use-package elfeed-org
      :config
      (elfeed-org)
      (setq rmh-elfeed-org-files (list "~/.config/emacs/feed.org"))))
#+end_src

=jj/setup-note-management= sets up =deft= for quick notes.
#+begin_src emacs-lisp
  (defun jj/setup-note-management ()
    "configure and install deft"
    (use-package deft
      :bind
      ("C-c d" . deft)
      :config
      (setq deft-directory "~/notes/"
            deft-default-extension "org")))
#+end_src

=jj/tools= installs and configures all tools specified above.
#+begin_src emacs-lisp
  (defun jj/tools ()
    "configure and install tools"
    (jj/setup-dumb-jump)
    (jj/setup-magit)
    (jj/setup-fzf)
    (jj/setup-pdf-tools)
    (jj/setup-vterm)
    (jj/setup-completions)
    (jj/setup-checkers)
    (jj/setup-snippets)
    (jj/setup-formatting)
    (jj/setup-rss)
    (jj/setup-note-management))
#+end_src

** Languages

=jj/setup-org-mode= configures =org-mode=. I use =~/org= as my =org= directory and hide emphasis markers because it's much easier to read that way. I enable =org-crypt= to allow reading and writing encrypted =org= files. I also replace bullets in bulleted lists with nicer looking icons. I configure faces to default to variable-width font, but switching to monospace where it is necessary. Finally, I use =visual-fill-column= to make =org= files display with a relatively narrow window centred in the frame.
#+begin_src emacs-lisp
  (defun jj/setup-org-mode ()
    "setup org-mode"
    (use-package org
      :hook
      (org-mode . (lambda ()
                    (variable-pitch-mode)
                    (display-line-numbers-mode -1)))
      :config
      (org-crypt-use-before-save-magic)
      (setq org-directory "~/org"
            org-hide-emphasis-markers t
            org-format-latex-options (plist-put org-format-latex-options :scale 2.0)
            org-return-follows-link t
            org-tags-exclude-from-inheritance '("crypt")
            org-crypt-key nil
            auto-save-default nil)
      (font-lock-add-keywords 'org-mode
                              '(("^ *\\([-]\\) "
                                 (0 (prog1 () (compose-region (match-beginning 1) (match-end 1) "•"))))))
      :custom-face
      (org-block ((t :font ,jj/mono-font)))
      (org-code ((t :font ,jj/mono-font (:inherit (shadow)))))
      (org-document-info-keyword ((t :font ,jj/mono-font (:inherit (shadow)))))
      (org-meta-line ((t :font ,jj/mono-font (:inherit (font-lock-comment-face)))))
      (org-verbatim ((t :font ,jj/mono-font (:inherit (shadow)))))
      (org-table ((t :font ,jj/mono-font (:inherit (shadow)))))
      (org-document-title ((t (:inherit title :height 2.0 :underline nil))))
      (org-level-1 ((t (:inherit outline-1 :weight bold :height 1.75))))
      (org-level-2 ((t (:inherit outline-2 :weight bold :height 1.5))))
      (org-level-3 ((t (:inherit outline-3 :weight bold :height 1.25))))
      (org-level-4 ((t (:inherit outline-4 :weight bold :height 1.1))))
      (org-level-5 ((t (:inherit outline-5 :height 1.1))))
      (org-level-6 ((t (:inherit outline-6))))))
#+end_src

=jj/setup-cmake= installs =cmake-mode=.
#+begin_src emacs-lisp
  (defun jj/setup-cmake ()
      "install cmake-mode"
      (use-package cmake-mode))
#+end_src

=jj/setup-go= installs =go-mode= and tools for =go= source code. Namely, =go-eldoc= gets documentation for =go= variables, functions, and arguments, =go-gen-tests= automatically generates tests for =go= code, and =go-guru= helps with refactoring =go= code.
#+begin_src emacs-lisp
  (defun jj/setup-go ()
    "install go-mode and tools for go"
    (use-package go-mode)
    (use-package go-eldoc
      :hook
      (go-mode . go-eldoc-setup))
    (use-package go-gen-test)
    (use-package go-guru
      :hook
      (go-mode . go-guru-hl-identifier-mode)))
#+end_src

=jj/setup-lua= installs =lua-mode=.
#+begin_src emacs-lisp
  (defun jj/setup-lua ()
    "install lua-mode"
    (use-package lua-mode))
#+end_src

=jj/setup-lisp= installs tools for Emacs Lisp. Namely =parinfer-rust-mode= which handles parentheses nicely in Emacs Lisp.
#+begin_src emacs-lisp :tangle yes
  (defun jj/setup-lisp ()
    "install tools for lisp"
    (use-package parinfer-rust-mode
      :hook
      (emacs-lisp-mode . parinfer-rust-mode)
      :init
      (setq parinfer-rust-auto-download t)))
#+end_src

=jj/setup-markdown= configures how Markdown is displayed (default to variable-width font and use monospace where necessary) and installs =markdown-mode=.
#+begin_src emacs-lisp
  (defun jj/setup-markdown ()
    "configure and install markdown-mode"
    (use-package markdown-mode
      :hook
      (markdown-mode . (lambda ()
                         (variable-pitch-mode)
                         (display-line-numbers-mode -1)))
      :config
      (setq markdown-hide-markup t)
      :custom-face
      (markdown-header-face ((t :font ,jj/var-font :weight bold)))
      (markdown-header-face-1 ((t (:inherit markdown-header-face :height 2.0))))
      (markdown-header-face-2 ((t (:inherit markdown-header-face :height 1.75))))
      (markdown-header-face-3 ((t (:inherit markdown-header-face :height 1.5))))
      (markdown-header-face-4 ((t (:inherit markdown-header-face :height 1.25))))
      (markdown-header-face-5 ((t (:inherit markdown-header-face :height 1.1))))
      (markdown-header-face-6 ((t (:inherit markdown-header-face :height 1.1))))
      (markdown-blockquote-face ((t :font ,jj/var-font)))
      (markdown-code-face ((t :font ,jj/mono-font)))
      (markdown-html-attr-name-face ((t :font ,jj/mono-font)))
      (markdown-html-attr-value-face ((t :font ,jj/mono-font)))
      (markdown-html-entity-face ((t :font ,jj/mono-font)))
      (markdown-html-tag-delimiter-face ((t :font ,jj/mono-font)))
      (markdown-html-tag-name-face ((t :font ,jj/mono-font)))
      (markdown-html-comment-face ((t :font ,jj/mono-font)))
      (markdown-header-delimiter-face ((t :font ,jj/mono-font)))
      (markdown-hr-face ((t :font ,jj/mono-font)))
      (markdown-inline-code-face ((t :font ,jj/mono-font)))
      (markdown-language-info-face ((t :font ,jj/mono-font)))
      (markdown-language-keyword-face ((t :font ,jj/mono-font)))
      (markdown-link-face ((t :font ,jj/mono-font)))
      (markdown-markup-face ((t :font ,jj/mono-font)))
      (markdown-math-face ((t :font ,jj/mono-font)))
      (markdown-metadata-key-face ((t :font ,jj/mono-font)))
      (markdown-metadata-value-face ((t :font ,jj/mono-font)))
      (markdown-missing-link-face ((t :font ,jj/mono-font)))
      (markdown-plain-url-face ((t :font ,jj/mono-font)))
      (markdown-reference-face ((t :font ,jj/mono-font)))
      (markdown-table-face ((t :font ,jj/mono-font)))
      (markdown-url-face ((t :font ,jj/mono-font)))))
#+end_src

=jj/setup-latex= installs tools for LaTeX. Namely, =auctex= for better integration with Emacs and =cdlatex= for environment and macro insertion.
#+begin_src emacs-lisp
  (defun jj/setup-latex ()
    "install tools for LaTeX"
    (use-package auctex
      :hook
      (LaTeX-mode . (lambda () (put 'LaTeX-mode 'eglot-language-id "latex"))))
    (use-package cdlatex
      :hook
      (LaTeX-mode . turn-on-cdlatex)))
#+end_src

=jj/setup-yaml= installs =yaml-mode=.
#+begin_src emacs-lisp :tangle yes
  (defun jj/setup-yaml ()
    "install yaml-mode"
    (use-package yaml-mode))
#+end_src

=jj/setup-nix= installs =nix-mode=.
#+begin_src emacs-lisp
  (defun jj/setup-nix ()
    "install nix-mode"
    (use-package nix-mode
      :mode
      "\\.nix\\'"))
#+end_src

=jj/languages= installs language modes and tools in addition to setting up =eglot= to run on those languages.
#+begin_src emacs-lisp
  (defun jj/languages ()
    "install language tools and configure eglot"
    (jj/setup-org-mode)
    (jj/setup-cmake)
    (jj/setup-go)
    (jj/setup-lua)
    (jj/setup-lisp)
    (jj/setup-markdown)
    (jj/setup-latex)
    (jj/setup-yaml)
    (jj/setup-nix)

    (global-set-key (kbd "C-c r") 'eglot-rename)
    (global-set-key (kbd "C-c a") 'eglot-code-actions)
    (use-package tree-sitter)
    (use-package tree-sitter-langs)
    (dolist (lang-hook '(sh-mode-hook
                         c-mode-hook
                         c++-mode-hook
                         cc-mode-hook
                         cmake-mode-hook
                         html-mode-hook
                         css-mode-hook
                         js-json-mode-hook
                         js-mode-hook
                         python-mode-hook
                         go-mode-hook
                         lua-mode-hook
                         markdown-mode-hook
                         tex-mode-hook
                         LaTeX-mode-hook
                         yaml-mode-hook
                         nix-mode-hook))
      (add-hook lang-hook (lambda ()
                            (eglot-ensure)
                            (tree-sitter-mode 1)
                            (tree-sitter-hl-mode 1)))))
#+end_src

** Main

#+begin_src emacs-lisp
  (jj/appearance)
  (jj/behaviour)
  (jj/tools)
  (jj/languages)
#+end_src