dotfiles/lain/.emacs.d/sandbox.org

* Packaging
** Package.el
[[http://wikemacs.org/wiki/Package.el][Package.el]] is the built-in package manager in Emacs. This is where the fun begins.
#+BEGIN_SRC emacs-lisp
  (require 'package)
  (setq package-archives
        '(("gnu"          . "https://elpa.gnu.org/packages/")
          ("melpa"        . "https://melpa.org/packages/")
          ("melpa-stable" . "https://stable.melpa.org/packages/")
          ("marmalade"    . "https://marmalade-repo.org/packages/")
          ("org"          . "https://orgmode.org/elpa/")))
  (setq package-enable-at-startup nil)
  (package-initialize)
#+END_SRC
** use-package
[[https://github.com/jwiegley/use-package][use-package]] is a nifty macro that interfaces with =Package.el=, keeping package-specific
configuration all in once place. It's pretty much the basis of this entire config.
#+BEGIN_SRC emacs-lisp
  (unless (package-installed-p 'use-package)
    (package-refresh-contents)
    (package-install 'use-package))

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

  (setq use-package-compute-statistics t)
  (setq use-package-always-ensure t)
  (setq use-package-always-pin "melpa")
  (setq use-package-verbose t)
#+END_SRC
*** Custom Keywords
A few useful =:keyword= macros that extend the vanilla =use-package= functionality.
**** :company
#+BEGIN_SRC emacs-lisp
  (defun use-package-company-normalize (name keyword args)
    "Normalize the KEYWORD with NAME :company with arguments ARGS into a list of pairs for the handler."
    (use-package-as-one (symbol-name keyword) args
      (lambda (label arg)
        (unless (or (consp arg) (use-package-non-nil-symbolp arg))
          (use-package-error
            (concat
              label
              "<symbol> or "
              "(<symbol or list of symbols> . <symbol or function>) or "
              "a list of these")))
        (use-package-normalize-pairs
          (lambda (k)
            (or (use-package-non-nil-symbolp k)
                (and (consp k)
                     (not (cdr (last k)))
                     (seq-every-p 'use-package-non-nil-symbolp k))))
          #'use-package-recognize-function
          name label arg))))

  ;;;###autoload
  (defun use-package-company-handler (name _keyword args rest state)
    "Generate a function and hook from each pair in NAME ARGS for the keyword with NAME :company, appending the forms to the ‘use-package’ declaration specified by REST and STATE."
    (use-package-concat
     (use-package-process-keywords name rest state)
     (mapcan
      (lambda (def)
        (let ((modes (car def))
              (backend (cdr def))
              (fun (intern (concat "use-package-company-add-" (symbol-name (cdr def))))))
          (when backend
            (append
             `((defun ,fun ()
                 (setq-local company-backends
                             (append company-backends '(,backend)))))
             (mapcar
              (lambda (mode)
                `(add-hook
                  ',(derived-mode-hook-name mode)
                  #',fun))
              (if (use-package-non-nil-symbolp modes) (list modes) modes))))))
      (use-package-normalize-commands args))))

  (defalias 'use-package-normalize/:company 'use-package-company-normalize)
  (defalias 'use-package-handler/:company 'use-package-company-handler)
  (defalias 'use-package-autoloads/:company 'use-package-autoloads-mode)

  (setq use-package-keywords
    (let ((idx (+ 1 (cl-position :hook use-package-keywords))))
      (append
        (seq-subseq use-package-keywords 0 idx)
        (list :company)
        (nthcdr idx use-package-keywords))))
#+END_SRC
* Keybinds
** which-key
[[https://github.com/justbur/emacs-which-key][which-key]] displays a popup in the minibuffer that shows 
keybindings following incomplete commands.
#+BEGIN_SRC emacs-lisp
  (use-package which-key
    :diminish
    :config
    (which-key-mode))
#+END_SRC
** General
[[https://github.com/noctuid/general.el][General]] is an excellent keybind manager that adds *tons* of useful macros.
Also set up a leader key and prefixes, like =\= in Vim.
#+BEGIN_SRC emacs-lisp
  (use-package general
    :config
    (general-create-definer jf-leader-def
      :keymaps 'override
      :states '(normal insert emacs)
      :prefix "SPC"
      :non-normal-prefix "M-SPC")

    (defun jf-create-wk-prefix (desc)
      "Helper for creating which-key prefix descriptions.
  Bind to a key with general to make which-key show DESC
  as the prefix's description"
      `(:ignore t :wk ,desc))

    (defmacro jf-create-definers (definitions)
      "A wrapper for general-create-definer.
    For every pair in DEFINITIONS, creates a leader
    with name jf-NAME-def and keybind SPC KEY or M-SPC KEY in normal mode."
      `(progn
         ,@(mapcan
            (lambda (def)
              (let ((key  (car def))
                    (name (cdr def)))
                `((general-create-definer ,(intern (concat "jf-" name "-def"))
                    :keymaps 'override
                    :states '(normal insert emacs)
                    :prefix ,(concat "SPC " key)
                    :non-normal-prefix ,(concat "M-SPC " key))
                  (jf-leader-def ,key ',(jf-create-wk-prefix name)))))
            definitions)))

    (jf-create-definers
     (("a" . "apps")
      ("b" . "buffers")
      ("f" . "files")
      ("g" . "git")
      ("h" . "help")
      ("m" . "major")
      ("o" . "org")
      ("p" . "projects")
      ("w" . "windows"))))
#+END_SRC
* Vim Emulation
** Evil
[[https://github.com/emacs-evil/evil][Evil]] is pretty much the entirety of Vim in Emacs.
#+BEGIN_SRC emacs-lisp
  (use-package evil
    :diminish undo-tree-mode

    :init
    (setq evil-want-integration t)
    (setq evil-want-keybinding nil)

    (defun jf-window-split ()
      (interactive)
      (evil-window-split)
      (evil-window-down 1))
    (defun jf-window-vsplit ()
      (interactive)
      (evil-window-vsplit)
      (evil-window-right 1))

    :config
    (evil-mode t)

    (jf-windows-def
     "-" #'jf-window-split
     "=" #'jf-window-vsplit
     "b" #'balance-windows
     "H" #'evil-window-far-left
     "J" #'evil-window-bottom
     "K" #'evil-window-top
     "L" #'evil-window-far-right
     "h" #'evil-window-left
     "j" #'evil-window-right
     "k" #'evil-window-down
     "l" #'evil-window-right
     "o" #'other-frame))
#+END_SRC
** Evil Collection
[[https://github.com/emacs-evil/evil-collection][Evil Collection]] adds Evil bindings for all the parts of Emacs that Evil
doesn't cover properly by default.
#+BEGIN_SRC emacs-lisp
  (use-package evil-collection
    :after evil
    :config
    (evil-collection-init
     '(calendar
       cmake-mode
       company
       custom
       debug
       dired
       doc-view
       elisp-mode
       elisp-refs
       eshell
       eval-sexp-fu
       flycheck
       flymake
       grep
       help
       ibuffer
       image
       image-dired
       info
       ivy
       js2-mode
       log-view
       man
       neotree
       python
       racer
       realgud
       which-key)))
#+END_SRC
** Evil Extensions
*** Avy
An enhanced version of =f= in Vim.
#+BEGIN_SRC emacs-lisp
  (use-package avy
    :general
    (:keymaps 'override
      :states 'normal
      "C-f" 'avy-goto-char-in-line
      "C-F" 'avy-goto-char))
#+END_SRC
*** evil-surround
Use =S= and a delimiter to surround in visual mode.
#+BEGIN_SRC emacs-lisp
(use-package evil-surround
    :after evil
    :diminish
    :config
    (global-evil-surround-mode 1))
#+END_SRC
* Emacs
** Defaults
*** Configuration Editing
Add functions for editing and reloading the Emacs config files.
#+BEGIN_SRC emacs-lisp
  (defun jf-edit-config ()
    (interactive)
    (find-file jf-config-file))

  (defun jf-edit-init ()
    (interactive)
    (find-file jf-init-file))

  (defun jf-reload-config ()
    (interactive)
    (org-babel-load-file jf-config-file))

  (jf-files-def
    "e"  (jf-create-wk-prefix "emacs files")
    "ec" #'jf-edit-config
    "ei" #'jf-edit-init
    "er" #'jf-reload-config)
#+END_SRC
*** Add to Load Path
Create and add a folder to the load path for local lisp files.
The folder itself and all descendants will be added to the path.
These packages will take precedence over other libraries with the same name.
#+BEGIN_SRC emacs-lisp
  (unless (file-exists-p jf-load-path)
    (make-directory jf-load-path))

  (let ((default-directory jf-load-path))
    (setq load-path
          (append
           (let ((load-path (copy-sequence load-path)))
             (append
              (copy-sequence (normal-top-level-add-to-load-path '(".")))
              (normal-top-level-add-subdirs-to-load-path)))
           load-path)))
#+END_SRC
*** File Not Found Functions
Offer to create parent folders when a file is opened
Offer to create nonexistant parent directories.
#+BEGIN_SRC emacs-lisp
  (defun jf-create-nonexistant-directories ()
    (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)))) ; last argument specifies to behave like `mkdir -p'

  (add-to-list 'find-file-not-found-functions #'jf-create-nonexistant-directories)
#+END_SRC
*** Customize Location
Make changes in =M-x customize= go somewhere other than being schlunked into =init.el=.
#+BEGIN_SRC emacs-lisp
  (setq custom-file (concat user-emacs-directory "_customize.el"))
  (load custom-file t)
#+END_SRC
*** Disable Bell
Shut up, emacs.
#+BEGIN_SRC emacs-lisp
  (setq ring-bell-function #'ignore)
#+END_SRC
*** Shorter Prompts
Make =yes-or-no= prompts ask for =y-or-n= instead. Saves loads of time™.
#+BEGIN_SRC emacs-lisp
  (defalias 'yes-or-no-p #'y-or-n-p)
#+END_SRC
*** Move Backup Files
By default, emacs gunks up every folder with =file~= backups 
and =#file#= lockfiles. Schlunk them all in =/tmp= instead.
#+BEGIN_SRC emacs-lisp
  (setq backup-directory-alist
        `((".*" . ,temporary-file-directory)))
  (setq auto-save-file-name-transforms
        `((".*" ,temporary-file-directory t)))
#+END_SRC
*** Secure auth-source
GPG encrypt stored auth tokens from [[https://www.gnu.org/software/emacs/manual/html_mono/auth.html][auth-source]] instead of storing them in plaintext.
#+BEGIN_SRC emacs-lisp
  (setq auth-sources '("~/.emacs.d/authinfo.gpg"))
#+END_SRC
*** Use UTF-8
Pleeeease default to UTF-8, Emacs.
#+BEGIN_SRC emacs-lisp
  (setq locale-coding-system 'utf-8)
  (set-terminal-coding-system 'utf-8)
  (set-keyboard-coding-system 'utf-8)
  (set-selection-coding-system 'utf-8)
  (prefer-coding-system 'utf-8)
#+END_SRC
*** Trash when Deleting
Don't permanently delete stuff unless asked.
#+BEGIN_SRC emacs-lisp
  (setq delete-by-moving-to-trash t)
#+END_SRC
*** Open Compressed Files
...automatically.
#+BEGIN_SRC emacs-lisp
  (setq auto-compression-mode t)
#+END_SRC
*** Save Minibuffer History
#+BEGIN_SRC emacs-lisp
  (savehist-mode 1)
  (setq history-length 1000)
#+END_SRC
*** Double Spaces
Why sentences would need double spaces to end I do not know.
#+BEGIN_SRC emacs-lisp
  (set-default 'sentence-end-double-space nil)
#+END_SRC
*** Eval Print Level
Print more stuff when running =C-x C-e= or =(eval-last-sexp)=
#+BEGIN_SRC emacs-lisp
  (setq eval-expression-print-level 100)
#+END_SRC
** UI
*** Font
Engage a nice coding font.
#+BEGIN_SRC emacs-lisp
  (add-to-list 'default-frame-alist '(font . "Fira Code 12"))
  (set-face-attribute 'default t :font "Fira Code 12")
#+END_SRC
*** Menu Bar
Disable the useless cruft at the top of the screen.
#+BEGIN_SRC emacs-lisp
  (menu-bar-mode -1)
  (tool-bar-mode -1)
  (scroll-bar-mode -1)
#+END_SRC
*** Modeline
**** Diminish
Adds support for =:diminish= in use-package declarations, which hides a mode from the modeline.
#+BEGIN_SRC emacs-lisp
(use-package diminish)
#+END_SRC
**** Column Number
Show line and column numbers in the modeline.
#+BEGIN_SRC emacs-lisp
(setq line-number-mode t)
(setq column-number-mode t)
#+END_SRC
*** Line Numbers
Use the default emacs relative line numbers, but switch to absolute lines when in insert mode.
#+BEGIN_SRC emacs-lisp
  (use-package nlinum-relative
    :config
    (nlinum-relative-setup-evil)
    :hook (prog-mode . nlinum-relative-mode))
#+END_SRC

*** Show Matching Parens
Shows matching parenthesis  
#+BEGIN_SRC emacs-lisp
(require 'paren)
(setq show-paren-delay 0)
(show-paren-mode)
#+END_SRC
*** Scrolling
Scroll smooth-ish-ly instead of jarring jumps.
#+BEGIN_SRC emacs-lisp
  (use-package smooth-scroll
    :config
    (smooth-scroll-mode t))
#+END_SRC
*** Dashboard
Show a cool custom dashboard buffer on startup.
#+BEGIN_SRC emacs-lisp
  (use-package dashboard
    :diminish page-break-lines-mode
    :config
    (dashboard-setup-startup-hook)
    (setq initial-buffer-choice (lambda () (get-buffer "*dashboard*")))

    :custom
    (dashboard-startup-banner 'logo)
    (dashboard-banner-logo-title "Welcome to Electronic Macs")
    (dashboard-items
     '((recents . 5)
       (agenda)
       (bookmarks . 5)
       (registers . 5))))
#+END_SRC
** Themes
*** pywal
Fancy dynamic color scheme generation from desktop wallpapers.
Requires additional setup on the machine itself.
#+BEGIN_SRC emacs-lisp
  (defvar jf-theme-pywal-path "~/.cache/wal/colors.el" "Path to the colorscheme generated by pywal.")

  (defun jf-theme-pywal ()
    (load-file jf-theme-pywal-path))

  (when (eq 'jf-theme 'jf-theme-pywal)
    (require 'filenotify)
    (file-notify-add-watch jf-theme-pywal-path '(change) #'jf-theme-pywal))
#+END_SRC
*** spacemacs
This theme is pretty fancy and has lots of supported modes.
#+BEGIN_SRC emacs-lisp
  (unless (package-installed-p 'spacemacs-theme)
    (package-install 'spacemacs-theme))

  (defun jf-theme-spacemacs ()
    (load-theme 'spacemacs-dark))
#+END_SRC
*** Transparency
Sets the window's transparency, to better admire choice wallpapers.
The first number in the alpha section applies when the window is
active, the second when it's inactive.
#+BEGIN_SRC emacs-lisp
(set-frame-parameter (selected-frame) 'alpha 85)
(add-to-list 'default-frame-alist '(alpha . 85))
#+END_SRC
    
*** Helpers
#+BEGIN_SRC emacs-lisp
  (defvar jf-theme #'jf-theme-pywal "Theme function to call.")

  (defun jf-apply-theme ()
    "Apply the current theme as set by jf-theme."
    (funcall jf-theme))

  (jf-apply-theme)
#+END_SRC
* Organization
** Capture Templates
All capture templates, from tasks to bookmarks.
*** Refile Targets
Goodize the refiling targets to allow refiling to arbitrary subtrees.
#+BEGIN_SRC emacs-lisp
  (defun jf-org-capture-refile ()
    (interactive)
    (setq-local org-refile-targets '((nil :maxlevel . 5)))
    (setq-local org-refile-use-outline-path t)
    (org-refile))
#+END_SRC
*** Tasks
#+BEGIN_SRC emacs-lisp
  (setq jf-org-capture-task-templates
        '(("t" "Todo")
          ("tg" "General" entry
           (file+headline "notes.org" "Todo")
           "** TODO %^{todo}\nNotes: %?\n")
          ("tt" "General (Date)" entry
           (file+olp+datetree "notes.org")
           "*** TODO %^{todo}\nDue: %^t\nNotes: %?\n")
          ("tT" "General (Date+Time)" entry
           (file+olp+datetree "notes.org")
           "*** TODO %^{todo}\nDue: %^T\nNotes: %?\n")
          ("ts" "School (Date)" entry
           (file+olp+datetree "notes.org")
           "*** TODO %^{todo}\nDue: %^t\nClass: %^{class}\nNotes: %?\n")
          ("tS" "School (Date+Time)" entry
           (file+olp+datetree "notes.org")
           "*** TODO %^{todo}\nDue: %^T\nClass: %^{class}\nNotes: %?\n")))
#+END_SRC
*** Bookmarks
#+BEGIN_SRC emacs-lisp
  (setq jf-org-capture-bookmark-templates
        '(("b" "Bookmark" entry
           (file+headline "links.org" "Unsorted Links")
           "** [[%^{link}][%^{name}]]\nCreated: %U\nAbout: %^{description}%?\n")))
#+END_SRC
*** Personal
#+BEGIN_SRC emacs-lisp
  (setq jf-org-capture-personal-templates
        '(("j" "Journal")
          ("jj" "Journal Entry" entry
           (file+olp+datetree "journal.org")
           "**** Today's Events\n%?")
          ("jt" "Thoughts" entry
           (file+headline "notes.org" "Thoughts")
           "** %^{summary}\n%U\n%?")
          ("jd" "Dream Journal Entry" entry
           (file+olp+datetree "dreams.org")
           "**** Dream\n%?")))
#+END_SRC
*** Protocol
#+BEGIN_SRC emacs-lisp
  (setq jf-org-capture-protocol-templates
        '(("w" "Website" entry
           (file+headline "sites.org" "Unsorted Sites")
           "** [[%:link][%:description%?]]\nCreated: %U\nAbout: %^{description}%?\n%:initial")))
#+END_SRC
*** All
Tie it all together.
#+BEGIN_SRC emacs-lisp
  (setq jf-org-capture-templates
        (append
         jf-org-capture-task-templates
         jf-org-capture-personal-templates
         jf-org-capture-bookmark-templates
         jf-org-capture-protocol-templates))
#+END_SRC
** Structure Templates
Defines expansions with =<= followed by a string in org-mode.
*** Source Blocks
#+BEGIN_SRC emacs-lisp
  (setq jf-org-source-structure-templates
        '(("el" "#+BEGIN_SRC emacs-lisp\n?\n#+END_SRC")))
#+END_SRC
*** All
Tie it all together.
#+BEGIN_SRC emacs-lisp
(setq jf-org-structure-templates
    (append
        jf-org-source-structure-templates))
#+END_SRC

** Org-mode
Keep org-mode up to date straight from the cow's utters.
If the manual is not on your computer, it's [[https://orgmode.org/manual/][here]].
#+BEGIN_SRC emacs-lisp
  (use-package org
    :pin org
    :mode ("\\.org\\'" . org-mode)
    :hook ((org-mode . org-indent-mode)
           (org-capture-mode . evil-insert-state))

    :general
    (jf-major-def
     :keymaps 'org-mode-map
     "e" 'org-export-dispatch
     "a" 'org-attach)
    (jf-org-def
     "a" 'org-agenda
     "c" 'org-capture
     "l" 'org-store-link
     "b" 'org-switchb
     "r" 'jf-org-capture-refile)
    :custom
    (org-directory "~/Documents/org")
    (org-agenda-files '("~/Documents/org/"))
    (org-default-notes-file "notes.org")
    (org-agenda-include-diary t)
    (org-src-window-setup 'current-window "Edit source code in the current window")
    (org-src-fontify-natively t "Highlight syntax in source blocks")
    (org-latex-to-pdf-process '("latexmk -f pdf %f") "Use pdflatex for export")
    (org-capture-templates jf-org-capture-templates)
    (org-structure-template-alist (append org-structure-template-alist jf-org-structure-templates)))
#+END_SRC
** Pretty org-mode bullets
Make bullets look choice
#+BEGIN_SRC emacs-lisp
  (use-package org-bullets
    :hook (org-mode . org-bullets-mode))
#+END_SRC
* Communication
* Web
* Tools
** Fuzzy Matching
Most facilities are provided by [[https://github.com/abo-abo/swiper][Ivy]] and friends, which build on existing emacs commands.
*** Smex
While the actual smex command is not in use, 
counsel-M-x will use it for sorting by usage.
#+BEGIN_SRC emacs-lisp
(use-package smex)
#+END_SRC
*** Ivy
#+BEGIN_SRC emacs-lisp
  (use-package ivy
    :init
    (defun jf-kill-current-buffer ()
      (interactive)
      (kill-buffer (current-buffer)))
    (defun jf-kill-all-buffers ()
      (interactive)
      (seq-do 'kill-buffer (buffer-list)))

    :general
    (jf-buffers-def
      "b" 'ivy-switch-buffer
      "v" 'ivy-push-view
      "V" 'ivy-pop-view
      "c" 'jf-kill-current-buffer
      "C" 'jf-kill-all-buffers)

    :custom
    (ivy-use-virtual-buffers t)
    (ivy-count-format "%d/%d"))
#+END_SRC
*** Counsel
A collection of ivy enhanced versions of common Emacs commands.
#+BEGIN_SRC emacs-lisp
  (use-package counsel
    :general
    ("M-x" 'counsel-M-x)
    (jf-leader-def
      :states 'normal
      "x" 'counsel-M-x)
    (jf-files-def
      "f" 'counsel-find-file)
    (jf-help-def
      "a" 'counsel-apropos
      "f" 'counsel-describe-function
      "k" 'counsel-descbinds
      "l" 'counsel-find-library
      "s" 'counsel-info-lookup-symbol
      "u" 'counsel-unicode-char
      "v" 'counsel-describe-variable))
#+END_SRC
*** Swiper
An ivy-ified replacement for isearch.
#+BEGIN_SRC emacs-lisp
  (use-package swiper
    :after evil
    :general
    (:keymaps 'override
      :states 'normal
      "/" 'swiper
      "n" 'evil-search-previous
      "N" 'evil-search-next))
#+END_SRC

** Neotree
A cool toggleable directory structure sidebar.
It needs icon fonts, installed with =M-x all-the-icons-install-fonts=.
#+BEGIN_SRC emacs-lisp
  (use-package all-the-icons)
  (use-package neotree
    :after all-the-icons
    :general
    (jf-apps-def
      "t" 'neotree-toggle)
    :custom
    (neo-theme (if (display-graphic-p) 'icons 'arrow)))
#+END_SRC
** Ranger
Brings the glory of [[https://github.com/ralesi/ranger.el][Ranger]] to Emacs.
#+BEGIN_SRC emacs-lisp
  (use-package ranger
    :commands (ranger deer))
#+END_SRC
** Sunshine
Allows retrieving OpenWeatherMap forecasts in the minibuffer.
#+BEGIN_SRC emacs-lisp
  (use-package sunshine
    :commands sunshine-forecast
    :general
    (jf-apps-def
     "w" #'sunshine-forecast)
    :custom
    (sunshine-location "New York, US")
    (sunshine-appid "7caf100277f14845e7f354c6590a09cb")
    (sunshine-show-icons t))
#+END_SRC
* Programming
** Formatting
*** Indentation
Set some *sane* defaults
#+BEGIN_SRC emacs-lisp
(setq jf-tab-width 4)
(setq-default python-indent-offset jf-tab-width)
(setq-default evil-shift-width jf-tab-width)
(setq-default c-basic-offset jf-tab-width)
; Disable annoying electric indent of previous lines
(setq-default electric-indent-inhibit t)
; Eat the whole tab when I press backspace
(setq backward-delete-char-untabify-method 'hungry)
#+END_SRC
Define some *useful* helper functions
#+BEGIN_SRC emacs-lisp
  (defun jf-indent-tabs (width)
    (interactive "nTab width: ")
    (setq tab-width width)
    (local-set-key (kbd "TAB") 'tab-to-tab-stop)
    (setq indent-tabs-mode t))

  (defun jf-indent-spaces (num)
    (interactive "nNumber of spaces: ")
    (setq tab-width num)
    (setq indent-tabs-mode nil))

  ;; Default
  (jf-indent-spaces 4)

  ;; Define functions for every level of indent that might need hooking
  (cl-macrolet
      ((jf-define-indent-funs (widths)
         `(progn
            ,@(mapcan
               (lambda (num)
                 `((defun ,(intern (concat "jf-indent-" (number-to-string num) "-spaces")) ()
                     (jf-indent-spaces ,num))
                   (defun ,(intern (concat "jf-indent-tabs-" (number-to-string num))) ()
                     (jf-indent-tabs ,num))))
               widths))))
    (jf-define-indent-funs (2 4 8)))

  ;; TODO: Replace with dedicated whitespace config
  (setq whitespace-style '(face tabs tab-mark trailing))
  (custom-set-faces
     '(whitespace-tab ((t (:foreground "#636363")))))

  ;; Make tabs visible
  (setq whitespace-display-mappings
     '((tab-mark 9 [124 9] [92 9])))

  (add-hook 'prog-mode-hook #'whitespace-mode)
#+END_SRC
*** Parentheses
**** Smartparens
[[https://github.com/Fuco1/smartparens][Smartparens]] handles parens for languages that aren't lispy.
#+BEGIN_SRC emacs-lisp
  (use-package smartparens
    :diminish
    :commands smartparens-mode
    :config
    (require 'smartparens-config))
#+END_SRC
**** ParEdit
And [[https://www.emacswiki.org/emacs/ParEdit][ParEdit]] handles the rest.
#+BEGIN_SRC emacs-lisp
  (use-package paredit
    :diminish
    :commands enable-paredit-mode)
#+END_SRC
**** Evil-Cleverparens
[[https://github.com/luxbock/evil-cleverparens][Evil-Cleverparens]] adds additional features to Evil all about
working with sexps, including keeping parens balanced when
using commands like =dd=.
#+BEGIN_SRC emacs-lisp
  (use-package evil-cleverparens
    :diminish
    :commands evil-cleverparens-mode)
#+END_SRC
**** Activation
Pick a suitable parenthesis editing mode for the
current major mode when entering any prog-mode derivative.
#+BEGIN_SRC emacs-lisp
  (defun jf-paren-mode ()
    (if (member major-mode '(emacs-lisp-mode
                             lisp-mode
                             lisp-interaction-mode
                             scheme-mode))
        (enable-paredit-mode)
      (smartparens-mode)))

  (add-hook 'prog-mode-hook #'jf-paren-mode)
#+END_SRC
*** Whitespace
**** ws-butler
Unobtrusively cleans up whitespace before EOLs 
as you edit, stopping the noisy commits generated 
from blanket trimming entire files.
#+BEGIN_SRC emacs-lisp
  (use-package ws-butler
    :hook (prog-mode . ws-butler-mode))
#+END_SRC
*** pretty-mode
[[https://github.com/pretty-mode/pretty-mode][pretty-mode]] redisplays parts of the Emacs buffer as pretty symbols.
#+BEGIN_SRC emacs-lisp
  (use-package pretty-mode
    :hook (prog-mode . pretty-mode)
    :config
    (pretty-deactivate-groups '(:arithmetic
                                :sub-and-superscripts))
    (pretty-activate-groups '(:equality
                              :ordering
                              :ordering-double
                              :ordering-triple
                              :arrows
                              :arrows-twoheaded
                              :punctuation
                              :logic
                              :sets)))
#+END_SRC

*** Prettify-Symbols-Mode
Allows custom unicode replacement of symbols. Fill in the gaps where
pretty-mode left off.
**** Python
#+BEGIN_SRC emacs-lisp
  (defun jf-prettify-python ()
    (dolist (pair '(;; Syntax
           ("in" .       #x2208)
           ("not in" .   #x2209)
           ("return" .   #x27fc)
           ("yield" .    #x27fb)
           ("for" .      #x2200)
           ;; Base Types
           ("int" .      #x2124)
           ("float" .    #x211d)
           ("str" .      #x1d54a)
           ("True" .     #x1d54b)
           ("False" .    #x1d53d)))
      (push pair prettify-symbols-alist)))

  (add-hook 'python-mode-hook #'prettify-symbols-mode)
  (add-hook 'python-mode-hook #'jf-prettify-python)
#+END_SRC

** Checkers
*** Flycheck
Flycheck highlights syntax errors in a few languages.
#+BEGIN_SRC emacs-lisp
  (use-package flycheck
    :hook (prog-mode . flycheck-mode))
#+END_SRC
*** Column 80 Highlight
Add a hotkey for highlighting column 80
and activate it in =prog-mode=
#+BEGIN_SRC emacs-lisp
  (use-package fill-column-indicator
    :init
    (setq fci-rule-use-dashes t)
    (setq fci-rule-column 80)
    :general
    (jf-major-def
      :keymaps 'prog-mode-map
      "8" 'fci-mode))
#+END_SRC

** Completion
*** Company
Company auto-completes stuff in the buffer, and company-quickhelp shows 
documentation popups when idling on a completion candidate.
#+BEGIN_SRC emacs-lisp
  (use-package company
    :hook (prog-mode . company-mode)
    :general
    (:keymaps 'company-active-map
              "C-SPC" 'company-abort)

    :custom
    (company-maximum-prefix-length 2)
    (company-idle-delay 0.2 "Decrease idle delay"))

  (use-package company-quickhelp
    :after company
    :hook (company-mode . company-quickhelp-mode))
#+END_SRC
** Snippets
Yasnippet adds support for custom snippets
#+BEGIN_SRC emacs-lisp
  (use-package yasnippet
    :hook (prog-mode . yas-minor-mode)
    :custom
    (yas-snippet-dirs
     '("~/.emacs.d/snippets"
       "~/.emacs.d/elpa/yasnippet-snippets-0.6/snippets")))
#+END_SRC

** Debugging
*** Realgud
[[https://github.com/realgud/realgud][Realgud]] is a modular frontend for many debuggers, right in Emacs.
#+BEGIN_SRC emacs-lisp
  (use-package realgud
    :commands
    (realgud:gdb
     realgud:lldb
     realgud:node-inspect
     realgud:pdb
     realgud:trepan3k))
#+END_SRC
*** RMSbolt
[[https://github.com/emacsmirror/rmsbolt][RMSbolt]] Shows disassembly in a buffer next to code, highlighting relevant regions.
#+BEGIN_SRC emacs-lisp
  (use-package rmsbolt
    :commands rmsbolt-mode)
#+END_SRC
** Git
*** Magit
It's magic git!
Keybinds [[https://github.com/emacs-evil/evil-magit][here]]
#+BEGIN_SRC emacs-lisp
  (use-package magit
    :general
    (jf-git-def
      "b" 'magit-blame-addition
      "B" 'magit-blame-reverse
      "s" 'magit-status))
#+END_SRC
It's *evil* magic git!
#+BEGIN_SRC emacs-lisp
(use-package evil-magit
  :after (evil magit))
#+END_SRC
*** Forge
Magic GitHub facilities for git forges such as GitHub and GitLab!
#+BEGIN_SRC emacs-lisp
  (use-package forge
    :after magit
    :preface
    (defvar jf-lcsr-git-host
          '("git.lcsr.rutgers.edu" "git.lcsr.rutgers.edu/api/v4" "git.lcsr.rutgers.edu" forge-gitlab-repository))
    :config
    (setq forge-alist (append forge-alist (list jf-lcsr-git-host))))
#+END_SRC
*** Smeargle
Highlights regions in files by last update time.
Older regions are more whitey and newer regions are more blacky.
#+BEGIN_SRC emacs-lisp
  (use-package smeargle
    :general
    (jf-git-def
      "H t" 'smeargle
      "H h" 'smeargle-commits
      "H c" 'smeargle-clear))
#+END_SRC
** Projects
Projectile provides project-level features like
make shortcuts and file switching
#+BEGIN_SRC emacs-lisp
  (use-package projectile
    :defer t
    :preface
    (defvar jf-projects-path "~/Documents/dev")

    :general
    (jf-leader-def
     "p" '(:keymap projectile-command-map))

    :config
    (projectile-mode 1)
    ;; Discover projects in jf-projects-path
    (let ((subdirs (directory-files jf-projects-path t)))
      (dolist (dir subdirs)
        (unless (member (file-name-nondirectory dir) '(".." "."))
          (when (file-directory-p dir)
            (let ((default-directory dir)
                  (projectile-cached-project-root dir))
              (when (projectile-project-p)
                (projectile-add-known-project (projectile-project-root))))))))

    :custom
    (projectile-completion-system 'ivy)
    (projectile-project-search-path (list jf-projects-path)))
#+END_SRC
** Languages
*** Fish
Mode for editing of scripts for the fish shell.
#+BEGIN_SRC emacs-lisp
  (use-package fish-mode
    :mode "\\.fish\\'")
#+END_SRC
*** Markdown
Mode for editing markdown.
#+BEGIN_SRC emacs-lisp
  (use-package markdown-mode
    :mode "\\.md\\'")
#+END_SRC

*** Python
Jedi for autocompletion sources in python-mode.
#+BEGIN_SRC emacs-lisp
  (use-package company-jedi
    :company python-mode)
#+END_SRC
*** Javascript
[[https://github.com/mooz/js2-mode][js2-mode]] improves the default js mode.
#+BEGIN_SRC emacs-lisp
  (use-package js2-mode
    :mode "\\.js\\'"
    :interpreter "node")
#+END_SRC
*** Web
Web-mode should give everything you need for a web-dev major mode.
Company integration is done with company-web.
#+BEGIN_SRC emacs-lisp
  (use-package web-mode
    :mode ("\\.html\\'"
           "\\.php\\'"
           "\\.blade\\.")
    :custom
    (web-mode-code-indent-offset 4)
    (web-mode-indent-style 4))

  (use-package company-web
    :company web-mode)
#+END_SRC

*** JSON
Mode for editing JSON files.
#+BEGIN_SRC emacs-lisp
  (use-package json-mode
    :mode "\\.json\\'")
#+END_SRC
*** YAML
Mode for editing YAML files.
#+BEGIN_SRC emacs-lisp
  (use-package yaml-mode
    :mode "\\.yaml\\'")
#+END_SRC

*** Arch PKGBUILD
Mode for editing PKGBUILD files.
#+BEGIN_SRC emacs-lisp
  (use-package pkgbuild-mode
    :mode ".*PKGBUILD\\'")
#+END_SRC

*** LaTeX
**** AUCTeX
AUCTeX is a major mode for editing TeX.
Company completions are handled by company-auctex and company-math.
#+BEGIN_SRC emacs-lisp
  (use-package tex
    :defer t
    :ensure auctex
    :general
    (jf-major-def
     :keymaps 'TeX-mode-map
     "e" 'TeX-command-run-all)

    :custom
    (TeX-auto-save t))

  (use-package company-auctex
    :company LaTeX-mode)

  (use-package company-math
    :company ((TeX-mode . company-math-symbols-latex)
              (TeX-mode . company-math-symbols-unicode)
              (TeX-mode . company-latex-commands)))
#+END_SRC
**** Cdlatex
cdlatex adds better TeX-specific template expansions and other niceties.
***** Environment
#+BEGIN_SRC emacs-lisp
  (setq jf-cdlatex-envs nil)
#+END_SRC
***** Commands
#+BEGIN_SRC emacs-lisp
  (setq jf-cdlatex-commands nil)
#+END_SRC
***** Math Symbols
#+BEGIN_SRC emacs-lisp
  (setq jf-cdlatex-symbols
        '((?I ("\\infty"))))
#+END_SRC
***** Setup
#+BEGIN_SRC emacs-lisp
  (use-package cdlatex
    :hook (LaTeX-mode . cdlatex-mode)
    :custom
    (cdlatex-env-alist jf-cdlatex-envs)
    (cdlatex-command-alist jf-cdlatex-commands)
    (cdlatex-math-symbol-alist jf-cdlatex-symbols))
#+END_SRC
*** Rust
#+BEGIN_SRC emacs-lisp
  (use-package rust-mode
    :mode "\\.rs\\'"
    :general)

  (use-package flycheck-rust
    :after flycheck
    :hook (rust-mode . flycheck-rust-setup))

  (use-package racer
    :hook ((rust-mode . racer-mode)
           (rust-mode . eldoc-mode))
    :custom
    (racer-cmd "~/.cargo/bin/racer")
    (racer-rust-src-path "~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src"))

  (use-package cargo
    :hook (rust-mode . cargo-minor-mode)
    :general
    (jf-major-def
     :keymaps 'rust-mode-map
     "b" #'cargo-process-build
     "r" #'cargo-process-run
     "t" #'cargo-process-test))
#+END_SRC
*** C/C++
**** Irony
Irony handles enhanced C/C++ operations powered by clang
company-irony for company integration
#+BEGIN_SRC emacs-lisp
  (use-package irony
    :hook ((c-mode c++-mode) . irony-mode)
           (irony-mode . irony-cdb-autosetup-compile-options))

  (use-package flycheck-irony
    :after flycheck
    :hook (irony-mode . flycheck-irony-setup))

  (use-package company-irony
    :company irony-mode)

  (use-package company-irony-c-headers
    :company irony-mode)
#+END_SRC