path: root/share/home/emacs/emacs.el

;;; init.el --- Initalization -*- lexical-binding: t; -*-
;;;
;;; Commentary:
;;; Various resources were used to hack together this config:
;;; - https://sanemacs.com/
;;; - https://rossabaker.com/configs/emacs/
;;;
;;; Code:

;;;;;;;;;;;;;;;;;;;;;;;
;;;     Startup     ;;;
;;;;;;;;;;;;;;;;;;;;;;;

;;; Startup - Use package ;;;

;; Most of this config is broken down into [[https://github.com/jwiegley/use-package][~use-package~]] stanzas. All
;; dependencies are managed by [[https://nixos.org/][Nix]]. Any package with a true ~:ensure~
;; keyword is found by [[https://github.com/nix-community/emacs-overlay#extra-library-functionality][~emacsWithPackagesFromUsePackage~]] to generate
;; the set of Emacs packages to install with Nix.
;;
;; In the brutish non-Nix world, ~:ensure~ triggers Emacs' own package
;; manager with willy nilly downloads. To prevent this, we tell
;; ~use-package~ to assume the package is there and merely look for its
;; autoloads.

(defun ross/use-package-ensure-already-installed
    (name _ensure state &optional _context)
  "Assumes the package is already installed.
Value for `use-package-ensure-function` that assumes the package
is already installed.  This is true in our Nix environment."
  (let ((autoloads-file-name (format "%s-autoloads" name)))
    (with-demoted-errors "Error loading autoloads: %s"
      (load autoloads-file-name t t))))

(setq use-package-ensure-function #'ross/use-package-ensure-already-installed)

;; ~use-package~ also by default appends ~"-hook"~ to all its hooks.
;; This impairs ripgreppability. Let's be explicit:

(setq use-package-hook-name-suffix nil)

;; use-package doesn't use itself. (Well, I think it could, but this
;; is the recommended approach...)

(eval-when-compile
  (require 'use-package))

;; some packages complain if I don't have this
(use-package bind-key
  :demand t
  :bind
  (:prefix-map rab/files-map
   :prefix "C-c f")
  :bind
  (:prefix-map rab/toggles-map
   :prefix "C-c t"))

;;; Startup - Benchmarking ;;;

(use-package benchmark-init
  :ensure t
  :demand t
  :hook (after-init . benchmark-init/deactivate)
  :config
  (benchmark-init/activate))

;;; Startup - Garbage collection ;;;

(use-package gcmh
  :ensure t
  :diminish
  :init (setq gc-cons-threshold (* 80 1024 1024))
  :hook (emacs-startup . gcmh-mode))

;;; Startup - Better cache location ;;;
(use-package no-littering
  :ensure t
  :init
  (setq no-littering-etc-directory "~/.cache/emacs/etc/"
        no-littering-var-directory "~/.cache/emacs/var/")
  (when (fboundp 'startup-redirect-eln-cache)
    (startup-redirect-eln-cache
     (convert-standard-filename
      (expand-file-name  "eln-cache/" no-littering-var-directory))))
  :config
  (no-littering-theme-backups))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;     Customization     ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;; Customization - Scrolling ;;;
;; TODO: Smooth scroll

;;; Customization - Theme ;;;

(use-package doom-themes
  :ensure t
  :config
  ;; Global settings (defaults)
  (setq doom-themes-enable-bold t    ; if nil, bold is universally disabled
        doom-themes-enable-italic t) ; if nil, italics is universally disabled
  (load-theme 'doom-one t)

  ;; Enable flashing mode-line on errors
  (doom-themes-visual-bell-config)
  ;; Corrects (and improves) org-mode's native fontification.
  (doom-themes-org-config))

;;; Customization - General settings ;;;

;; Disable menu-bar, tool-bar, and scroll-bar.
(if (fboundp 'menu-bar-mode)
    (menu-bar-mode -1))
(if (fboundp 'tool-bar-mode)
    (tool-bar-mode -1))
(if (fboundp 'scroll-bar-mode)
    (scroll-bar-mode -1))

;; Useful Defaults
(setq-default cursor-type 'bar)           ; Line-style cursor similar to other text editors
(setq inhibit-startup-screen t)           ; Disable startup screen
(setq initial-scratch-message "")         ; Make *scratch* buffer blank
(setq-default frame-title-format '("%b")) ; Make window title the buffer name
(setq ring-bell-function 'ignore)         ; Disable bell sound
(fset 'yes-or-no-p 'y-or-n-p)             ; y-or-n-p makes answering questions faster
(show-paren-mode 1)                       ; Show closing parens by default
(global-auto-revert-mode t)               ; Auto-update buffer if file has changed on disk
(setopt create-lockfiles nil)             ; Don't create lockfiles
(electric-pair-mode 1)                    ; Autopairs

;;; Customization - Highlight current line ;;;

(use-package hl-line
  :hook (on-first-buffer . global-hl-line-mode))

;;; Customization - Evil ;;;

;; Set up vi keybinds
(use-package evil
  :config
  (evil-mode 1))

;;; Customization - Direnv support ;;;

(use-package envrc
  :ensure t
  :hook (on-first-file . envrc-global-mode))

;;; Customziation - Completion framework ;;;

(use-package helm
  :init
  (helm-mode 1)
  :config
  (setq helm-completion-style 'emacs))

(use-package fussy
  :config
  (push 'fussy completion-styles)
  (setq
   ;; For example, project-find-file uses 'project-files which uses
   ;; substring completion by default. Set to nil to make sure it's using
   ;; flx.
   completion-category-defaults nil
   completion-category-overrides nil))

;;; Customization - Project management ;;;

(use-package projectile
  :bind-keymap ("C-c p" . projectile-command-map)
  :config
  (projectile-mode +1))

;;; Customization - Completions ;;;

(use-package company
  :init (global-company-mode))

;;; Customization - Syntax checking ;;;

(use-package flycheck
  :init (global-flycheck-mode))

;;; Customization - Line numbers ;;;

(when (version<= "26.0.50" emacs-version )
  (global-display-line-numbers-mode))

;;; Customization - Which key ;;;

(use-package which-key
  :init (which-key-mode +1))

;;;;;;;;;;;;;;;;;;;;;;;;;
;;;     Languages     ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;

;;; Langauges - Emacs lisp ;;;

;; Preserve indentation in org mode source blocks
(dolist (pair '((org-src-preserve-indentation . t) (org-src-tab-acts-natively . t)))
  (add-to-list 'safe-local-variable-values pair))

;;; Languages - Nix ;;;

(use-package nix-mode
  :mode "\\.nix\\'")

;;; Languages - Coq ;;;

(use-package proof-general
  :mode ("\\.v\\'" . coq-mode))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;     Useful modes     ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;; Useful modes - magit ;;;

(use-package magit)

;;; emacs.el ends here