path: root/Emacs/.config/emacs/config.org

#+title: Emacs configuration
#+author: Aryadev Chavali
#+description: My Emacs configuration
#+property: header-args:emacs-lisp :tangle config.el :comments link :results none
#+options: toc:nil
#+startup: noindent

#+begin_center
My configuration for (a very specific form of) Emacs
#+end_center
#+latex: \clearpage
#+toc: headlines

* Basics
Firstly, set full name and mail address.  This is used in encryption
and mailing.
#+begin_src emacs-lisp
(setq user-full-name "Aryadev Chavali"
      user-mail-address "aryadev@aryadevchavali.com")
#+end_src

Let's set all yes or no questions to single letter responses.
#+begin_src emacs-lisp
(fset 'yes-or-no-p 'y-or-n-p)
#+end_src

Set the encoding to UTF-8-Unix by default.
#+begin_src emacs-lisp
(use-package emacs
  :straight nil
  :init
  (setq-default buffer-file-coding-system 'utf-8-unix
                save-buffer-coding-system 'utf-8-unix))
#+end_src

Setup no-littering, which cleans up many of the default directories in
Emacs.
#+begin_src emacs-lisp
(use-package no-littering
  :demand t
  :init
  (setq no-littering-etc-directory (expand-file-name ".config/"  user-emacs-directory)
        no-littering-var-directory (expand-file-name ".local/" user-emacs-directory)))
#+end_src
** File saves and custom file
Setup automatic saving for files (in case of system failure) and
auto-revert-mode (which refreshes the buffer on changes to the
underlying file).  Along with that, set the custom-file (which holds
temporary customisation)  in the etc folder.
#+begin_src emacs-lisp
(use-package emacs
  :straight nil
  :init
  (setq backup-directory-alist `(("." . ,(no-littering-expand-var-file-name "saves/")))
        global-auto-revert-non-file-buffers t
        auto-revert-verbose nil)
  (setq custom-file (no-littering-expand-etc-file-name "custom.el"))
  :config
  (global-auto-revert-mode 1))
#+end_src
* Custom functionality
Functions that don't require a packages to work other than Emacs,
which means I can define them early.  These are used much later in the
config.
** Toggle buffer
Like VSCode's toggling feature for just the terminal but now for
any buffer of choice, as long as I can generate it via a command.
#+begin_src emacs-lisp
(with-eval-after-load "window"
  (defmacro +oreo/create-toggle-function (func-name buf-name
                                                    buf-create
                                                    &optional accept-numeric)
    "Generate a function named FUNC-NAME that toggles the buffer with
name BUF-NAME, using BUF-CREATE to generate it if buffer BUF-NAME
does not exist already.

BUF-NAME cannot be a regexp, it must be a fixed name.

ACCEPT-NUMERIC modifies the function to allow numeric arguments
via C-u.  Mostly used in Eshell."
    (let ((interactive-arg
           (if accept-numeric '(interactive "p") '(interactive)))
          (arguments
           (if accept-numeric '(&optional arg) nil))
          (buffer-name (if accept-numeric
                           `(if (= arg 1)
                                ,buf-name
                              (concat ,buf-name "<" (int-to-string arg) ">"))
                         buf-name))
          (buffer-create (if accept-numeric
                             `(if (= arg 1)
                                  (,buf-create)
                                (,buf-create arg))
                           `(,buf-create))))
      `(defun ,func-name ,arguments
         ,interactive-arg
         (let* ((buffer (or (get-buffer ,buffer-name)
                            ,buffer-create))
                (displayed (get-buffer-window buffer)))
           (if displayed
               (delete-window displayed)
             (display-buffer buffer)
             (select-window (get-buffer-window buffer))))))))
#+end_src
** Auto-run command after-save-hook
Define a macro which creates hooks into the ~after-save-hook~.  On
certain ~conditions~ being met, ~to-run~ is evaluated.
#+begin_src emacs-lisp
(use-package simple
  :straight nil
  :config
  (defmacro +oreo/create-auto-save (conditions &rest to-run)
    "Create a hook for after saves, where (on CONDITIONS being met)
TO-RUN is evaluated. "
    `(add-hook 'after-save-hook #'(lambda ()
                                    (interactive)
                                    (when ,conditions
                                      ,@to-run)))))
#+end_src
** Procedure
A ~lambda~ which takes no arguments is a procedure.  This macro
generates procedures, with the parameters of the macro being the body
of the procedure.  It returns it in quoted form, as that is the most
common use of this macro.

(You may notice ~proc~ is used where the return value is irrelevant).
#+begin_src emacs-lisp
(defmacro proc (&rest BODY)
  "For a given list of forms BODY, return a quoted 0 argument
lambda."
  `(quote (lambda nil ,@BODY)))
#+end_src
** System specificity
A macro that acts as a switch case on ~(system-name)~ which allows the
writing of system specific code.  For me this is for my desktop and
laptop, particularly for font sizes.  Though there may be an easier
solution than this, this seems simple enough.
#+begin_src emacs-lisp
(defmacro +oreo/sys-name-cond (&rest pairs)
  "Switch case on result of function `system-name'.

Each pair in PAIRS is typed as: (string . (forms...)) where the
string represents the system name to test, and forms being the
consequence if true."
  `(cond
    ,@(mapcar #'(lambda (pair)
      ;; (str . forms..) -> ((string= str (system-name))
      ;; forms...)
      (let ((name (car pair))
      (body (cdr pair)))
        `((string= ,name (system-name)) ,@body)))
  pairs)))
#+end_src

In [[file:early-init.el][early-init.el]] I set the number of
native-workers to 4, which isn't necessarily optimal when
loading/compiling the rest of this file depending on the machine I
use:
- On my laptop (=spiderboy=) I'd prefer to have it use 2-3 threads so I
  can actually use the rest of the laptop while waiting for
  compilation
- On my desktop (=oldboy=) I'd prefer to use 4-6 threads as I can
  afford more, so I can get a faster load up.
#+begin_src emacs-lisp
(+oreo/sys-name-cond
 ("spiderboy"
  (setq native-comp-async-jobs-number 3))
 ("oldboy"
  (setq native-comp-async-jobs-number 6)))
#+end_src
** Clean buffer list
Instead of cleaning my buffer list manually, selectively preserving
some fixed set of buffers, this function does it for me.  Preserves
any buffers in ~+oreo/keep-buffer~ and kills the rest.
#+begin_src emacs-lisp
(defconst +oreo/keep-buffers
  (list "config.org" "*scratch*"
        "*dashboard*" "*Messages*"
        "*Warnings*")
  "List of buffer names to preserve.")

(defun +oreo/clean-buffer-list ()
  "Kill all buffers except any with names in +oreo/keep-buffers."
  (interactive)
  (mapcar #'(lambda (buf)
              (if (not (member (buffer-name buf) +oreo/keep-buffers))
                  (kill-buffer buf)))
          (buffer-list)))
#+end_src
* Aesthetics
General look and feel of Emacs (mostly disabling stuff I don't like).
** Themes
*** Dark theme
My preferred dark theme is my own "personal-primary" theme which is
stored in the Emacs lisp folder (look at [[file:elisp/personal-primary-theme.el][this file]]).  It tries to use
the primary colours for everything, leading to a colour -> meaning
relation.

I have an older version of this theme that uses a homogeneous colour
scheme ([[file:elisp/personal-theme.el][this file]])
#+begin_src emacs-lisp
(use-package custom
  :demand t
  :straight nil
  :init
  (setq custom-theme-directory (concat user-emacs-directory "elisp/"))
  :config
  (load-theme 'personal-primary t))
#+end_src
*** Light theme
I'm not very good at designing light themes as I don't really use
them.  However they are necessary in high light situations where a
dark mode would strain the eyes too much.  So I built a custom theme
on top of the default Emacs theme, "personal-light" (look at [[file:elisp/personal-light-theme.el][this
file]]).

I don't use it by default but I may need to switch between light and
dark easily, so here's a command to switch between them.

#+begin_src emacs-lisp
(use-package custom
  :defer t
  :straight nil
  :commands +oreo/switch-theme
  :init
  (defvar +oreo/theme 'dark)
  :config
  (defun +oreo/switch-theme ()
    (interactive)
    (cond
     ((eq +oreo/theme 'dark)
      (load-theme 'personal-light t)
      (setq +oreo/theme 'light))
     ((eq +oreo/theme 'light)
      (load-theme 'personal-primary t)
      (setq +oreo/theme 'dark)))))

#+end_src
** Font size
Set font size to 140 if on my desktop (oldboy) or 175 if on my laptop
(spiderboy).
#+begin_src emacs-lisp
(use-package faces
  :straight nil
  :config
  (+oreo/sys-name-cond
   ("spiderboy" (set-face-attribute 'default nil :height 175))
   ("oldboy" (set-face-attribute 'default nil :height 140))))
#+end_src
** Startup screen
The default startup screen is quite bad in all honesty, great for
first time users who have no idea what is going on but terrible for
regular users.

The scratch buffer is an interaction buffer made when Emacs is first
started, as a way to quickly prototype Emacs Lisp code.  When startup
screen is disabled, this buffer is the first thing presented on boot
for Emacs.  So we can use it to store some useful information.

As I use [[*Org mode][org-mode]] to compile my Emacs, it is available
essentially at startup, so I use it for the scratch buffer.  That way,
I can use all the abilities of org-mode (particularly writing a system
of code using =#+RESULTS=) in an ephemeral buffer at startup!
#+begin_src emacs-lisp
(use-package emacs
  :straight nil
  :init
  (setq
   inhibit-startup-screen t
   initial-major-mode 'org-mode
   initial-scratch-message (format "#+title: Scratch buffer
,#+author: %s
,#+description: Emacs v%s

Booted in %s!
" user-full-name emacs-version (emacs-init-time))
   ring-bell-function 'ignore))
#+end_src
** Blinking cursor
Turn off blinking-cursor-mode as [[*Hl-line][hl-line]] is better.
#+begin_src emacs-lisp
(use-package frame
  :straight nil
  :config
  (blink-cursor-mode 0))
#+end_src
** Fringes
Turning off borders in my window manager was a good idea, so turn off
the borders for Emacs.
#+begin_src emacs-lisp
(use-package fringe
  :after dashboard
  :straight nil
  :config
  (fringe-mode 0))
#+end_src
** Mode line
A mode line in an editor can provide a LOT of information, or very
little.  I customised the Emacs modeline to give me a bit of info,
~telephone-line~ to give me a lot.

Currently I use the default mode line with some customisation;
simplicity is above all.
*** Emacs Mode-line
#+begin_src emacs-lisp
(defun +mode-line/generate-padding ()
  (let ((wid (frame-width))
        (str ""))
    (dotimes (n (floor (/ wid 7)))
      (setq str (concat str " ")))
    str))

(setq-default
 mode-line-format
 (list
  "%l:%c    " ;; Line and column
  "%p[" ;; Where in file + Evil state
  '(:eval (upcase
           (substring
            (format "%s" (if (bound-and-true-p evil-state)
                             evil-state
                           ""))
            0 1)))
  "]    "
  "%+%b("
  '(:eval (format "%s" major-mode))
  ")    "
  "%I    "
  '(:eval (+mode-line/generate-padding))
  '(vc-mode vc-mode)
  mode-line-misc-info
  mode-line-end-spaces))
#+end_src
*** WIP Telephone-line
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Telephone-line is a mode-line package for Emacs which prioritises
extensibility.  It also looks much nicer than the default mode line
with colouring and a ton of presentations to choose from.
#+begin_src emacs-lisp
(use-package telephone-line
  :init
  (defface +telephone/position-face '((t (:foreground "red" :background "grey10"))) "")
  (defface +telephone/mode-face '((t (:foreground "white" :background "dark green"))) "")
  (defface +telephone/file-info-face '((t (:foreground "white" :background "Dark Blue"))) "")
  :custom
  (telephone-line-faces
   '((evil      . telephone-line-modal-face)
     (modal     . telephone-line-modal-face)
     (ryo       . telephone-line-ryo-modal-face)
     (accent    . (telephone-line-accent-active . telephone-line-accent-inactive))
     (nil         . (mode-line                    . mode-line-inactive))
     (position  . (+telephone/position-face     . mode-line-inactive))
     (mode      . (+telephone/mode-face         . mode-line-inactive))
     (file-info . (+telephone/file-info-face    . mode-line-inactive))))
  (telephone-line-primary-left-separator    'telephone-line-halfcos-left)
  (telephone-line-secondary-left-separator  'telephone-line-halfcos-hollow-left)
  (telephone-line-primary-right-separator   'telephone-line-identity-right)
  (telephone-line-secondary-right-separator 'telephone-line-identity-hollow-right)
  (telephone-line-height 24)
  (telephone-line-evil-use-short-tag nil)
  :config
  (telephone-line-defsegment +telephone/buffer-or-filename ()
                             (cond
                              ((buffer-file-name)
                               (if (and (fboundp 'projectile-project-name)
                                        (fboundp 'projectile-project-p)
                                        (projectile-project-p))
                                   (list ""
                                         (funcall (telephone-line-projectile-segment) face)
                                         (propertize
                                          (concat "/"
                                                  (file-relative-name (file-truename (buffer-file-name))
                                                                      (projectile-project-root)))
                                          'help-echo (buffer-file-name)))
                                 (buffer-file-name)))
                              (t (buffer-name))))

  (telephone-line-defsegment +telephone/get-position ()
                             `(,(concat "%lL:%cC"
                                        (if (not mark-active)
                                            ""
                                          (format " | %dc" (- (+ 1 (region-end)) (region-beginning)))))))

  (setq-default
   telephone-line-lhs '((mode telephone-line-major-mode-segment)
                        (file-info telephone-line-input-info-segment)
                        (position +telephone/get-position)
                        (accent   +telephone/buffer-or-filename
                                  telephone-line-process-segment))
   telephone-line-rhs '((accent telephone-line-flycheck-segment telephone-line-misc-info-segment
                                telephone-line-projectile-segment)
                        (file-info telephone-line-filesize-segment)
                        (evil  telephone-line-evil-tag-segment)))
  (telephone-line-mode))
#+end_src
* Core packages
Packages that are absolutely necessary for the rest of the
configuration.  These yield core functionality such as keybinding,
modal editing, completion, auto typing to name a few.
** General
General provides a great solution for binding keys.  It has evil and
use-package support so it fits nicely into configuration.  In this
case, I define a "definer" for the "LEADER" keys.  Leader is bound to
~SPC~ and it's functionally equivalent to the doom/spacemacs leader.
Local leader is bound to ~SPC ,~ and it's similar to doom/spacemacs
leader but doesn't try to fully assimilate the local-leader map,
instead just picking stuff I think is useful.  This forces me to learn
only as many bindings as I find necessary; no more, no less.

I also define prefix leaders for differing applications.  These are
quite self explanatory by their name and provide a nice way to
visualise all bindings under a specific heading just by searching the
code.
#+begin_src emacs-lisp
(use-package general
  :demand t
  :config
  ;; General which key definitions for leaders
  (general-def
    :states '(normal motion)
    "SPC"   'nil
    "\\"    '(nil :which-key "Local leader")
    "SPC c" '(nil :which-key "Code")
    "SPC f" '(nil :which-key "File")
    "SPC t" '(nil :which-key "Shell")
    "SPC m" '(nil :which-key "Toggle modes")
    "SPC a" '(nil :which-key "Applications")
    "SPC s" '(nil :which-key "Search")
    "SPC b" '(nil :which-key "Buffers")
    "SPC q" '(nil :which-key "Quit/Literate")
    "SPC i" '(nil :which-key "Insert")
    "SPC d" '(nil :which-key "Directories"))

  (general-create-definer leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC")

  (general-create-definer local-leader
    :states '(normal motion)
    :prefix "\\")

  (general-create-definer code-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC c")

  (general-create-definer file-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC f")

  (general-create-definer shell-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC t")

  (general-create-definer mode-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC m")

  (general-create-definer app-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC a")

  (general-create-definer search-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC s")

  (general-create-definer buffer-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC b")

  (general-create-definer quit-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC q")

  (general-create-definer insert-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC i")

  (general-create-definer dir-leader
    :states '(normal motion)
    :keymaps 'override
    :prefix "SPC d")

  (general-create-definer general-nmmap
    :states '(normal motion))

  (defalias 'nmmap #'general-nmmap)

  (general-evil-setup t))
#+end_src
*** Some binds in Emacs
Some bindings that I couldn't fit elsewhere easily.
#+begin_src emacs-lisp
(use-package emacs
  :straight nil
  :general
  (general-def
    "C-x d" #'delete-frame)

  (nmmap
    "C--" #'text-scale-decrease
    "C-=" #'text-scale-increase)

  (leader
    "SPC" '(execute-extended-command :which-key "M-x")
    "'"   '(browse-url-emacs :which-key "Open url in Emacs")
    ";"   'eval-expression
    ":"   `(,(proc (interactive) (switch-to-buffer "*scratch*"))
            :which-key "Switch to *scratch*")
    "!"   '(async-shell-command :which-key "Async shell command")
    "h" '(help-command :which-key "Help"))

  (mode-leader
    "t" #'+oreo/switch-theme)

  (code-leader
    "F" `(,(proc (interactive) (find-file "~/Code/"))
          :which-key "Open ~/Code/"))

  (file-leader
    "f" #'find-file
    "F" #'find-file-other-frame
    "s" #'save-buffer
    "p" `(,(proc (interactive)
                 (find-file (concat user-emacs-directory "config.org")))
          :which-key "Open config.org"))

  (quit-leader
    "q" #'save-buffers-kill-terminal
    "c" #'+literate/compile-config
    "l" #'+literate/load-config
    "d" #'delete-frame)

  (search-leader "i" #'imenu))
#+end_src
** Evil
My editor journey started off with Vim rather than Emacs, so my brain
has imprinted on its style.  Thankfully Emacs is super extensible so
there exists a package (more of a supreme system) for porting Vim's
modal editing style to Emacs, called Evil (Emacs Vi Layer).

However there are a lot of packages in Vim that provide greater
functionality, for example 'vim-surround'.  Emacs, by default, has
these capabilities but there are further packages which integrate them
into Evil.
*** Evil core
Setup the evil package, with some opinionated keybindings:
- Switch ~evil-upcase~ and ~evil-downcase~ because I use ~evil-upcase~
  more
- Switch ~evil-goto-mark~ and ~evil-goto-mark-line~ as I'd rather have
  the global one closer to the home row
- Use 'T' character as an action for transposing objects
#+begin_src emacs-lisp
(use-package evil
  :demand t
  :hook (after-init-hook . evil-mode)
  :general
  (leader
    "w"  '(evil-window-map :which-key "Window")
    "wd" #'delete-frame)

  (nmmap
    "TAB" #'evil-jump-item
    "r"   #'evil-replace-state
    "zC"  #'hs-hide-level
    "'"   #'evil-goto-mark
    "`"   #'evil-goto-mark-line
    "C-w" #'evil-window-map
    "gu"  #'evil-upcase
    "gU"  #'evil-downcase
    "T"   nil)

  (nmmap
    :infix "T"
    "w" #'transpose-words
    "c" #'transpose-chars
    "s" #'transpose-sentences
    "p" #'transpose-paragraphs
    "e" #'transpose-sexps
    "l" #'transpose-lines)
  :init
  (setq evil-want-keybinding nil
        evil-split-window-below t
        evil-vsplit-window-right t
        evil-want-abbrev-expand-on-insert-exit t
        evil-undo-system #'undo-tree)
  :config
  (fset #'evil-window-vsplit #'make-frame))
#+end_src
*** Evil surround
Evil surround is a port for vim-surround.
#+begin_src emacs-lisp
(use-package evil-surround
  :after evil
  :config
  (global-evil-surround-mode))
#+end_src
*** Evil commentary
Allows generalised commenting of objects easily.
#+begin_src emacs-lisp
(use-package evil-commentary
  :after evil
  :config
  (evil-commentary-mode))
#+end_src
*** Evil multi cursor
Setup for multi cursors in Evil mode.  Don't let evil-mc setup it's own
keymap because it uses 'gr' as its prefix, which I don't like.
#+begin_src emacs-lisp
(use-package evil-mc
  :after evil
  :init
  (defvar evil-mc-key-map (make-sparse-keymap))
  :general
  (nmap
    :infix "gz"
    "q" #'evil-mc-undo-all-cursors
    "d" #'evil-mc-make-and-goto-next-match
    "j" #'evil-mc-make-cursor-move-next-line
    "k" #'evil-mc-make-cursor-move-prev-line
    "j" #'evil-mc-make-cursor-move-next-line
    "m" #'evil-mc-make-all-cursors
    "z" #'evil-mc-make-cursor-here
    "r" #'evil-mc-resume-cursors
    "s" #'evil-mc-pause-cursors
    "u" #'evil-mc-undo-last-added-cursor)
  :config
  ;; (evil-mc-define-vars)
  ;; (evil-mc-initialize-vars)
  ;; (add-hook 'evil-mc-before-cursors-created #'evil-mc-pause-incompatible-modes)
  ;; (add-hook 'evil-mc-before-cursors-created #'evil-mc-initialize-active-state)
  ;; (add-hook 'evil-mc-after-cursors-deleted  #'evil-mc-teardown-active-state)
  ;; (add-hook 'evil-mc-after-cursors-deleted  #'evil-mc-resume-incompatible-modes)
  ;; (advice-add #'evil-mc-initialize-hooks :override #'ignore)
  ;; (advice-add #'evil-mc-teardown-hooks :override #'evil-mc-initialize-vars)
  ;; (advice-add #'evil-mc-initialize-active-state :before #'turn-on-evil-mc-mode)
  ;; (advice-add #'evil-mc-teardown-active-state :after #'turn-off-evil-mc-mode)
  ;; (add-hook 'evil-insert-state-entry-hook #'evil-mc-resume-cursors)
  (global-evil-mc-mode))
#+end_src

*** Evil collection
Provides a community based set of keybindings for most modes in
Emacs.  I don't necessarily like all my modes having these bindings
though, as I may disagree with some.  So I use it in a mode to mode basis.
#+begin_src emacs-lisp
(use-package evil-collection
  :after evil)
#+end_src
** Completion
Emacs is a text based interface.  Completion is its bread and butter
in providing good user experience.  By default Emacs provides
'completions-list' which produces a buffer of options which can be
searched and selected.  We can take this further though!

Ido and Icomplete are packages distributed with Emacs to provide
greater completion interfaces.  They utilise the minibuffer to create
a more interactive experience, allowing incremental searches and
option selection.

Ivy and Helm provide more modern interfaces, though Helm is quite
heavy.  Ivy, on the other hand, provides an interface similar to Ido
with less clutter and better customisation options.
*** Ivy
Ivy is a completion framework for Emacs, and my preferred one.  It has
a great set of features with little to no pain with setting up.
**** Ivy Core
Setup for ivy, in preparation for counsel.  Turn on ivy-mode just
after init.

Setup vim-like bindings for the minibuffer ("M-(j|k)" for down|up the
selection list).
#+begin_src emacs-lisp
(use-package ivy
  :defer t
  :hook (after-init-hook . ivy-mode)
  :general
  (general-def
    :keymaps  'ivy-minibuffer-map
    "C-j"     #'ivy-yank-symbol
    "M-j"     #'ivy-next-line-or-history
    "M-k"     #'ivy-previous-line-or-history
    "C-c C-e" #'ivy-occur)
  (general-def
    :keymaps  'ivy-switch-buffer-map
    "M-j"     #'ivy-next-line-or-history
    "M-k"     #'ivy-previous-line-or-history)
  (nmap
    :keymaps '(ivy-occur-mode-map ivy-occur-grep-mode-map)
    "RET" #'ivy-occur-press-and-switch
    "J" #'ivy-occur-press
    "g" #'ivy-occur-revert-buffer
    "q" #'quit-window
    "D" #'ivy-occur-delete-candidate
    "W" #'ivy-wgrep-change-to-wgrep-mode
    "{" #'compilation-previous-file
    "}" #'compilation-next-file)
  :config
  (require 'counsel nil t)
  (setq ivy-height 10
        ivy-wrap t
        ivy-fixed-height-minibuffer t
        ivy-use-virtual-buffers nil
        ivy-virtual-abbreviate 'full
        ivy-on-del-error-function #'ignore
        ivy-use-selectable-prompt t)
  (with-eval-after-load "amx"
    (setq amx-backend 'ivy))
  (with-eval-after-load "evil"
    (evil-set-initial-state 'ivy-occur-mode 'normal)
    (evil-set-initial-state 'ivy-occur-grep-mode 'normal)))
#+end_src
**** Counsel
Setup for counsel.  Load after ivy and helpful.
#+begin_src emacs-lisp
(use-package counsel
  :after ivy
  :general
  (search-leader
    "s" #'counsel-grep-or-swiper
    "r" #'counsel-rg)
  (file-leader
    "r" #'counsel-recentf)
  (insert-leader
    "c" #'counsel-unicode-char)
  (general-def
    [remap describe-bindings]        #'counsel-descbinds
    [remap load-theme]               #'counsel-load-theme)
  :config
  (setq ivy-initial-inputs-alist '((org-insert-link . "^"))
        counsel-describe-function-function #'helpful-callable
        counsel-describe-variable-function #'helpful-variable
        counsel-grep-swiper-limit 1500000
        ivy-re-builders-alist '((swiper . ivy--regex-plus)
                                (counsel-grep-or-swiper . ivy--regex-plus)
                                (counsel-rg . ivy--regex-plus)
                                (t . ivy--regex-ignore-order)))
  (counsel-mode))
#+end_src
**** WIP Ivy posframe
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
This makes ivy minibuffer windows use child frames.
Very nice eyecandy, but can get kinda annoying.
#+begin_src emacs-lisp
(use-package ivy-posframe
  :hook (ivy-mode-hook . ivy-posframe-mode)
  :straight t
  :init
  (setq ivy-posframe-parameters
        '((left-fringe      . 0)
          (right-fringe     . 0)
          (background-color . "grey7")))

  (setq ivy-posframe-display-functions-alist
        '((t . ivy-posframe-display-at-window-center))))
#+end_src
**** WIP Counsel etags
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Counsel etags allows me to search generated tag files for tags.  I
already have a function defined to generate the tags, so it's just
searching them which I find to be a bit of a hassle, and where this
package comes in.

This has been replaced by [[*xref][xref]] which is inbuilt.
#+begin_src emacs-lisp
(use-package counsel-etags
  :after counsel
  :general
  (search-leader
    "t" #'counsel-etags-find-tag))
#+end_src
*** WIP Ido
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Ido is a very old completion package that still works great to this
day.  Though it is limited in its scope (and may thus be called a
completion add-on rather than a full on framework), it is still a very
powerful package.  With the use of ido-completing-read+, it may be used
similarly to a fully fledged completion framework.

#+begin_src emacs-lisp
(use-package ido
  :demand t
  :general
  (general-def
    :keymaps '(ido-buffer-completion-map
               ido-file-completion-map
               ido-file-dir-completion-map
               ido-common-completion-map)
    (kbd "M-j")   #'ido-next-match
    (kbd "M-k")   #'ido-prev-match
    (kbd "C-x o") #'evil-window-up)
  :init
  (setq ido-decorations
        (list "{" "}" " \n" " ..." "[" "]" " [No match]" " [Matched]"
              " [Not readable]" " [Too big]" " [Confirm]")
        completion-styles '(flex partial-completion intials emacs22))
  (setq-default ido-enable-flex-matching t
                ido-enable-dot-prefix t
                ido-enable-regexp nil)
  (with-eval-after-load "magit"
    (setq magit-completing-read-function 'magit-ido-completing-read))
  :config
  (ido-mode)
  (ido-everywhere))
#+end_src
**** Ido ubiquitous
Ido completing-read+ is a package that extends the ido package to work
with more text based functions.
#+begin_src emacs-lisp
(use-package ido-completing-read+
  :after ido
  :config
  (ido-ubiquitous-mode +1))
#+end_src
*** Amx
Amx is a fork of Smex that works to enhance the
execute-extended-command interface.  It also provides support for ido
or ivy (though I'm likely to use ido here) and allows you to switch
between them.

It provides a lot of niceties such as presenting the key bind when
looking for a command.

#+begin_src emacs-lisp
(use-package amx
  :config
  (amx-mode))
#+end_src
*** Orderless
Orderless sorting method for completion, probably one of the best
things ever.
#+begin_src emacs-lisp
(use-package orderless
  :after (ivy ido)
  :config
  (setf (alist-get t ivy-re-builders-alist) 'orderless-ivy-re-builder))
#+end_src
*** Completions-list
In case I ever use the completions list, some basic commands to look
around.
#+begin_src emacs-lisp
(use-package simple
  :straight nil
  :general
  (nmmap
    :keymaps 'completion-list-mode-map
    "l"   #'next-completion
    "h"   #'previous-completion
    "ESC" #'delete-completion-window
    "q"   #'quit-window
    "RET" #'choose-completion)
  :config
  (with-eval-after-load "evil"
    (setq evil-emacs-state-modes (cl-remove-if
                                  #'(lambda (x) (eq 'completions-list-mode x))
                                  evil-emacs-state-modes))
    (add-to-list 'evil-normal-state-modes 'completions-list-mode)))
#+end_src
*** Company
Company is the auto complete system I use.  I don't like having heavy
setups for company as it only makes it slower to use.  In this case,
just setup some evil binds for company.
#+begin_src emacs-lisp
(use-package company
  :straight t
  :hook
  (prog-mode-hook   . company-mode)
  (eshell-mode-hook . company-mode)
  :general
  (imap
    "C-SPC" #'company-complete)
  (general-def
    :states '(normal insert)
    "M-j" #'company-select-next
    "M-k" #'company-select-previous))
#+end_src
** Pretty symbols
Prettify symbols mode allows for users to declare 'symbols' that
replace text within certain modes.  Though this may seem like useless
eye candy, it has aided my comprehension and speed of recognition
(recognising symbols is easier than words).

Essentially a use-package keyword which makes declaring pretty symbols
for language modes incredibly easy.  Checkout my [[C/C++][C/C++]] configuration
for an example.
#+begin_src emacs-lisp
(use-package prog-mode
  :straight nil
  :init
  (setq prettify-symbols-unprettify-at-point t)
  :config
  (with-eval-after-load "use-package-core"
    (add-to-list 'use-package-keywords ':pretty)
    (defun use-package-normalize/:pretty (_name-symbol _keyword args)
      args)

    (defun use-package-handler/:pretty (name _keyword args rest state)
      (use-package-concat
       (use-package-process-keywords name rest state)
       (mapcar
        #'(lambda (arg)
            (let ((mode (car arg))
                  (rest (cdr arg)))
              `(add-hook
                ',mode
                #'(lambda nil
                    (setq prettify-symbols-alist ',rest)
                    (prettify-symbols-mode)))))
        args)))))
#+end_src

Here's a collection of keywords and possible associated symbols for
any prog language of choice.  Mostly for reference and copying.
#+begin_example
("null"   . "Ø")
("list"   . "ℓ")
("string" . "𝕊")
("true"   . "⊤")
("false"  . "⊥")
("char"   . "ℂ")
("int"    . "ℤ")
("float"  . "ℝ")
("!"      . "¬")
("&&"     . "∧")
("||"      . "∨")
("for"    . "∀")
("return" . "⟼")
("print"  . "ℙ")
("lambda" . "λ")
#+end_example
** Window management
Emacs' default window management is quite bad, eating other windows on
a whim and not particularly caring for the current window setup.
Thankfully you can change this via the ~display-buffer-alist~ which
matches buffer names with how the window for the buffer should be
displayed.  I add a use-package keyword to make ~display-buffer-alist~
records within use-package.

I have no idea whether it's optimal AT ALL, but it works for me.
#+begin_src emacs-lisp
(use-package window
  :straight nil
  :general
  (buffer-leader
    "b" #'switch-to-buffer
    "d" #'kill-current-buffer
    "K" #'kill-buffer
    "j" #'next-buffer
    "k" #'previous-buffer
    "D" '(+oreo/clean-buffer-list :which-key "Kill most buffers"))
  :init
  (with-eval-after-load "use-package-core"
    (add-to-list 'use-package-keywords ':display)
    (defun use-package-normalize/:display (_name-symbol _keyword args)
      args)

    (defun use-package-handler/:display (name _keyword args rest state)
      (use-package-concat
       (use-package-process-keywords name rest state)
       (mapcar
        #'(lambda (arg)
            `(add-to-list 'display-buffer-alist
                          ',arg))
        args)))))
#+end_src
*** Some display records
Using the ~:display~ keyword, setup up some ~display-buffer-alist~
records.  This is mostly for packages that aren't really configured
(like [[info:woman][woman]]) or packages that were configured before
(like [[Ivy][Ivy]]).
#+begin_src emacs-lisp
(use-package window
  :straight nil
  :defer t
  :display
  ("\\*Process List\\*"
   (display-buffer-at-bottom)
   (window-height . 0.25))

  ("\\*\\(Ido \\)?Completions\\*"
   (display-buffer-in-side-window)
   (window-height . 0.25)
   (side . bottom))

  ("\\*ivy-occur.*"
   (display-buffer-at-bottom)
   (window-height . 0.25))

  ("\\*Async Shell Command\\*"
   (display-buffer-at-bottom)
   (window-height . 0.25)))
#+end_src
** Auto typing
Snippets are a pretty nice way of automatically inserting code.  Emacs
provides a ton of packages by default to do this, but there are great
packages to install as well.

Abbrevs and skeletons make up a popular solution within Emacs default.
Abbrevs are for simple expressions wherein the only input is the key,
and the output is some Elisp function.  They provide a lot of inbuilt
functionality and are quite useful.  Skeletons, on the other hand, are
for higher level insertions

The popular external solution is Yasnippet.  Yasnippet is a great
package for snippets, which I use heavily in programming and org-mode.
I setup here the global mode for yasnippet and a collection of
snippets for ease of use.
*** Abbrevs
Just define a few abbrevs for various date-time operations.  Also
define a macro that will assume a function for the expansion, helping
with abstracting a few things away.
#+begin_src emacs-lisp
(use-package abbrev
  :straight nil
  :hook
  (prog-mode-hook . abbrev-mode)
  (text-mode-hook . abbrev-mode)
  :init
  (defmacro +abbrev/define-abbrevs (abbrev-table &rest abbrevs)
    `(progn
       ,@(mapcar #'(lambda (abbrev)
                     `(define-abbrev
                        ,abbrev-table
                        ,(car abbrev)
                        ""
                        (proc (insert ,(cadr abbrev)))))
                 abbrevs)))
  (setq save-abbrevs nil)
  :config
  (+abbrev/define-abbrevs
   global-abbrev-table
   ("sdate"
    (format-time-string "%Y-%m-%d" (current-time)))
   ("stime"
    (format-time-string "%H:%M:%S" (current-time)))
   ("sday"
    (format-time-string "%A" (current-time)))
   ("smon"
    (format-time-string "%B" (current-time)))))
#+end_src
*** WIP Skeletons
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Defines a macro for generating a skeleton + abbrev for a given mode.
Doesn't sanitise inputs because I assume callers are /rational/ actors
who would *only* use this for their top level Emacs config.

Honestly didn't find much use for this currently, so disabled.
#+begin_src emacs-lisp
(use-package skeleton
  :straight nil
  :after abbrev
  :config
  (defmacro +autotyping/gen-skeleton-abbrev (mode abbrev &rest skeleton)
    (let* ((table          (intern (concat (symbol-name mode) "-abbrev-table")))
           (skeleton-name  (intern (concat "+skeleton/" (symbol-name mode) "/" abbrev))))
      `(progn
         (define-skeleton
           ,skeleton-name
           ""
           ,@skeleton)
         (define-abbrev ,table
           ,abbrev
           ""
           ',skeleton-name)))))
#+end_src
*** Auto insert
Allows inserting text immediately upon creating a new buffer with a
given name.  Supports skeletons for inserting text.  To make it easier
for later systems to define their own auto inserts, I define a
~use-package~ keyword ~auto-insert~ which allows one to define an
entry for ~auto-insert-alist~.
#+begin_src emacs-lisp
(use-package autoinsert
  :straight nil
  :demand t
  :hook (after-init-hook . auto-insert-mode)
  :config
  (with-eval-after-load "use-package-core"
    (add-to-list 'use-package-keywords ':auto-insert)
    (defun use-package-normalize/:auto-insert (_name-symbol _keyword args)
      args)
    (defun use-package-handler/:auto-insert (name _keyword args rest state)
      (use-package-concat
       (use-package-process-keywords name rest state)
       (mapcar
        #'(lambda (arg)
            `(add-to-list
              'auto-insert-alist
              ',arg))
        args)))))
#+end_src
*** Yasnippet default
Look at the snippets [[file:.config/yasnippet/snippets/][folder]] for all snippets I've got.
#+begin_src emacs-lisp
(use-package yasnippet
  :after evil
  :hook
  (prog-mode-hook . yas-minor-mode)
  (text-mode-hook . yas-minor-mode)
  :general
  (insert-leader
    "i" #'yas-insert-snippet)
  :config
  (yas-load-directory (no-littering-expand-etc-file-name "yasnippet/snippets")))
#+end_src
* Small packages
** ISearch
ISearch is the default incremental search application in Emacs.  I use
~evil-search-forward~ so I don't interact with isearch that much, but
I may need it occasionally.
#+begin_src emacs-lisp
(use-package isearch
  :straight nil
  :general
  (:keymaps 'isearch-mode-map
   "M-s" #'isearch-repeat-forward))
#+end_src
** Info
Info is GNU's attempt at better man pages.  Most Emacs packages have
info pages so I'd like nice navigation options.
#+begin_src emacs-lisp
(use-package info
  :straight nil
  :general
  (nmmap
    :keymaps 'Info-mode-map
    "h" #'evil-backward-char
    "k" #'evil-previous-line
    "l" #'evil-forward-char
    "H" #'Info-history-back
    "L" #'Info-history-forward
    "RET" #'Info-follow-nearest-node))
#+end_src
** Display line numbers
I don't really like line numbers, I find them similar to [[*Fringes][fringes]] as
useless space, but at least it provides some information.  Sometimes
it can help with doing repeated commands so a toggle option is
necessary.
#+begin_src emacs-lisp
(use-package display-line-numbers
  :straight nil
  :commands display-line-numbers-mode
  :general
  (mode-leader
    "l" #'display-line-numbers-mode)
  :init
  (setq-default display-line-numbers-type 'relative))
#+end_src
** esup
I used to be able to just use [[file:elisp/profiler-dotemacs.el][profile-dotemacs.el]], when my Emacs
config was smaller, but now it tells me very little information about
where my setup is inefficient due to the literate config.  Just found
this ~esup~ thing and it works perfectly, exactly how I would prefer
getting this kind of information.  It runs an external Emacs instance
and collects information from it, so it doesn't require restarting
Emacs to profile.

#+begin_src emacs-lisp
(use-package esup
  :defer t)
#+end_src
** xref
Find definitions, references and general objects using tags without
external packages.  Provided by default in Emacs and just requires a
way of generating a =TAGS= file for your project.  Helps with minimal
setups for programming without heavier packages like [[*Eglot][Eglot]].

[[*Projectile][Projectile]] provides a nice way to generate tags.
#+begin_src emacs-lisp
(use-package xref
  :straight nil
  :display
  ("\\*xref\\*"
   (display-buffer-at-bottom)
   (inhibit-duplicate-buffer . t)
   (window-height . 0.25))
  :general
  (code-leader
    "t" '(nil :which-key "Tags"))
  (code-leader
    :infix "t"
    "t" #'xref-find-apropos
    "d" #'xref-find-definitions
    "r" #'xref-find-references)
  (nmmap
    :keymaps 'xref--xref-buffer-mode-map
    "RET" #'xref-goto-xref
    "J" #'xref-next-line
    "K" #'xref-prev-line
    "g" #'xref-revert-buffer
    "q" #'quit-window))
#+end_src
** Hl-line
Highlights the current line, much better than a blinking cursor.
#+begin_src emacs-lisp
(use-package hl-line
  :straight t
  :hook (text-mode-hook . hl-line-mode)
  :hook (prog-mode-hook . hl-line-mode))
#+end_src
** Recentf
Recentf provides a method of keeping track of recently opened files.
#+begin_src emacs-lisp
(use-package recentf
  :straight nil
  :hook (emacs-startup-hook . recentf-mode))
#+end_src
** Projectile
Projectile is a project management package which integrates with Emacs
very well.  It essentially provides alternative Emacs commands scoped
to the current 'project', based on differing signs that a directory is
a 'project'.
#+begin_src emacs-lisp
(use-package projectile
  :after evil
  :hook (emacs-startup-hook . projectile-mode)
  :general
  (leader "p" '(projectile-command-map :which-key "Projectile"))
  :init
  (setq projectile-tags-command "ctags -Re -f \"%s\" %s \"%s\""))
#+end_src
*** Counsel projectile
Counsel integration for projectile commands, very nice.
#+begin_src emacs-lisp
(use-package counsel-projectile
  :after (projectile counsel)
  :config
  (counsel-projectile-mode +1))
#+end_src
** Avy
Setup avy with leader.  As I use ~avy-goto-char-timer~ a lot, use the
~C-s~ bind which replaces isearch.  Switch isearch to M-s in case I
need to use it.
#+begin_src emacs-lisp
(use-package avy
  :after evil
  :general
  (nmmap
    "C-s" #'avy-goto-char-timer
    "M-s" #'isearch-forward)
  (search-leader
    "l" #'avy-goto-line))
#+end_src
** Ace window
Though evil provides a great many features in terms of window
management, ace window can provide some nicer chords for higher
management of windows (closing, switching, etc).

#+begin_src emacs-lisp
(use-package ace-window
  :after evil
  :custom
  (aw-keys '(?a ?s ?d ?f ?g ?h ?j ?k ?l))
  :general
  (nmmap
    [remap evil-window-next] #'ace-window))
#+end_src
** Helpful
Helpful provides a modernised interface for some common help
commands.  I replace ~describe-function~, ~describe-variable~ and
~describe-key~ by their helpful counterparts.
#+begin_src emacs-lisp
(use-package helpful
  :after ivy
  :commands (helpful-callable helpful-variable)
  :general
  (general-def
    [remap describe-function] #'helpful-callable
    [remap describe-variable] #'helpful-variable
    [remap describe-key]      #'helpful-key)
  :display
  ("\\*helpful.*"
   (display-buffer-at-bottom)
   (inhibit-duplicate-buffer . t)
   (window-height . 0.25))
  :config
  (evil-define-key 'normal helpful-mode-map "q" #'quit-window))
#+end_src
** Which-key
Which key uses the minibuffer when performing a keybind to provide
possible options for the next key.
#+begin_src emacs-lisp
(use-package which-key
  :config
  (which-key-mode))
#+end_src
** Keychord
Keychord is only really here for this one chord I wish to define: "jk"
for exiting insert state.
#+begin_src emacs-lisp
(use-package key-chord
  :after evil
  :config
  (key-chord-define evil-insert-state-map "jk" #'evil-normal-state)
  (key-chord-mode))
#+end_src
** (Rip)grep
Grep is a great piece of software, a necessary tool in any Linux
user's inventory.  By default Emacs has a family of functions to use
grep, presenting results in a ~compilation~ style.  ~grep~ searches
files, ~rgrep~ searches in a directory using the ~find~ program and
~zgrep~ searches archives.  This is a great solution for a general
computer environment; essentially all Linux installs will have ~grep~
and ~find~ installed.

Ripgrep is a Rust program that attempts to perform better than grep,
and it actually does.  This is because of a set of optimisations, such
as checking the =.gitignore= to exclude certain files from being
searched.  The ripgrep package provides utilities to ripgrep projects
and files for strings.  Though [[*Ivy][ivy]] comes with ~counsel-rg~, it uses
Ivy's completion framework rather than the ~compilation~ style
buffers, which sometimes proves very useful.

Of course, this requires installing the rg binary which is available
in most repositories nowadays.
*** Grep
I have no use for standard 'grep'; ~counsel-swiper~ does the same
thing faster and within Emacs lisp.  ~rgrep~ is useful though.
#+begin_src emacs-lisp
(use-package grep
  :straight nil
  :display
  ("^\\*grep.*"
   (display-buffer-at-bottom)
   (window-height . 0.25)
   (display-buffer-reuse-window))
  :general
  (search-leader
    "d" #'rgrep))
#+end_src
*** rg
#+begin_src emacs-lisp
(use-package rg
  :after grep
  :general
  (search-leader
    "R" #'rg)
  (:keymaps 'rg-mode-map
   "]]" #'rg-next-file
   "[[" #'rg-prev-file
   "q"  #'quit-window)
  :init
  (setq rg-group-result t
        rg-hide-command t
        rg-show-columns nil
        rg-show-header t
        rg-custom-type-aliases nil
        rg-default-alias-fallback "all"
        rg-buffer-name "*ripgrep*"))
#+end_src
** Olivetti
Olivetti provides a focus mode for Emacs, which makes it look a bit
nicer with fringes.  I also define ~+olivetti-mode~ which will
remember and clear up any window configurations on the frame, then
when turned off will reinsert them - provides a nice way to quickly
focus on a buffer.
#+begin_src emacs-lisp
(use-package olivetti
  :commands (+olivetti-mode)
  :general
  (mode-leader
    "o" #'+olivetti-mode)
  :init
  (setq-default olivetti-body-width 0.6)
  (setq olivetti-style nil)
  (add-hook 'olivetti-mode-on-hook  (proc (interactive) (text-scale-increase 1)))
  (add-hook 'olivetti-mode-off-hook (proc (interactive) (text-scale-decrease 1)))
  :config
  (defun +olivetti-mode ()
    (interactive)
    (if (not olivetti-mode)
        (progn
          (window-configuration-to-register 1)
          (delete-other-windows)
          (olivetti-mode t))
      (jump-to-register 1)
      (olivetti-mode 0))))
#+end_src
** All the Icons
Nice set of icons with a great user interface to manage them.
#+begin_src emacs-lisp
(use-package all-the-icons
  :straight t
  :defer t
  :commands (all-the-icons-insert)
  :general
  (insert-leader
    "e" #'all-the-icons-insert))
#+end_src
** Hide mode line
Custom minor mode to toggle the mode line.  Check it out at
[[file:elisp/hide-mode-line.el][elisp/hide-mode-line.el]].
#+begin_src emacs-lisp
(use-package hide-mode-line
  :straight nil
  :load-path "elisp/"
  :defer t
  :general
  (mode-leader
    "m" #'hide-mode-line-mode))
#+end_src
** Save place
Saves current place in a buffer permanently, so on revisiting the file
(even in a different Emacs instance) you go back to the place you were
at last.
#+begin_src emacs-lisp
(use-package saveplace
  :straight nil
  :config
  (save-place-mode))
#+end_src
* Applications
Applications are greater than packages; they provide a set of
functionality to create an interface in Emacs.  Emacs comes with
applications and others may be installed.
** WIP Dashboard
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Dashboard creates a custom dashboard for Emacs that replaces the
initial startup screen in default Emacs.  It has a lot of customising
options.

Unfortunately not that useful, many things are easier to invoke
directly such as recent files or project changing.
#+begin_src emacs-lisp
(use-package dashboard
  :straight t
  :demand t
  :general
  (app-leader
    "b" #'dashboard-refresh-buffer)
  (:states '(normal motion emacs)
   :keymaps 'dashboard-mode-map
   "q" (proc (interactive) (kill-this-buffer)))
  (nmmap
    :keymaps 'dashboard-mode-map
    "r" #'dashboard-jump-to-recent-files
    "p" #'dashboard-jump-to-projects
    "}" #'dashboard-next-section
    "{" #'dashboard-previous-section)
  :init
  (setq initial-buffer-choice nil
        dashboard-banner-logo-title "Oreomacs"
        dashboard-center-content t
        dashboard-set-init-info t
        dashboard-startup-banner (no-littering-expand-etc-file-name "dashboard/logo.png")
        dashboard-set-footer t
        dashboard-set-navigator t
        dashboard-items '((projects . 5)
                          (recents . 5))
        dashboard-footer-messages (list
                                   "Collecting parentheses..."
                                   "Linking 'coffee_machine.o'..."
                                   "Uploading ip to hacker named 4chan..."
                                   "Dividing by zero..."
                                   "Solving 3-sat..."
                                   "Obtaining your health record..."
                                   (format "Recompiling Emacs for the %dth time..." (random 1000))
                                   "Escaping the cycle of samsara..."))
  :config
  (dashboard-setup-startup-hook))
#+end_src
** EWW
Emacs Web Wowser is the inbuilt text based web browser for Emacs.  It
can render images and basic CSS styles but doesn't have a JavaScript
engine, which makes sense as it's primarily a text interface.
#+begin_src emacs-lisp
(use-package eww
  :defer t
  :general
  (app-leader
    "w" #'eww)
  :straight nil
  :config
  (with-eval-after-load "evil-collection"
    (evil-collection-eww-setup)))
#+end_src
** Calendar
Calendar is a simple inbuilt application that helps with date
functionalities.  I add functionality to copy dates from the calendar
to the kill ring and bind it to "Y".
#+begin_src emacs-lisp
(use-package calendar
  :straight nil
  :defer t
  :commands (+calendar/copy-date +calendar/toggle-calendar)
  :display
  ("\\*Calendar\\*"
   (display-buffer-at-bottom)
   (inhibit-duplicate-buffer . t)
   (window-height . 0.17))
  :general
  (nmmap
    :keymaps 'calendar-mode-map
    "Y" #'+calendar/copy-date)
  (app-leader
    "d" #'+calendar/toggle-calendar)
  :config
  (defun +calendar/copy-date ()
    "Copy date under cursor into kill ring."
    (interactive)
    (if (use-region-p)
        (call-interactively #'kill-ring-save)
      (let ((date (calendar-cursor-to-date)))
        (when date
          (setq date (encode-time 0 0 0 (nth 1 date) (nth 0 date) (nth 2 date)))
          (kill-new (format-time-string "%Y-%m-%d" date))))))
  (+oreo/create-toggle-function
   +calendar/toggle-calendar
   "*Calendar*"
   calendar
   nil))
#+end_src
** Mail
Mail is a funny thing; most people use it just for business or
advertising and it's come out of use in terms of personal
communication in the west for the most part (largely due to "social"
media applications).  However, this isn't true for the open source and
free software movement who heavily use mail for communication.

Integrating mail into Emacs helps as I can send source code and
integrate it into my workflow just a bit better.
*** Notmuch
#+begin_src emacs-lisp
(use-package notmuch
  :defer t
  :commands (notmuch +mail/flag-thread)
  :general
  (app-leader "m" #'notmuch)
  (nmap
    :keymaps 'notmuch-search-mode-map
    "f" #'+mail/flag-thread)
  :init
  (defconst +mail/signature "---------------\nAryadev Chavali")
  (defconst +mail/local-dir (concat user-emacs-directory ".mail/"))
  (setq notmuch-show-logo nil
        notmuch-search-oldest-first nil
        notmuch-hello-sections '(notmuch-hello-insert-saved-searches
                                 notmuch-hello-insert-alltags
                                 notmuch-hello-insert-recent-searches)
        notmuch-archive-tags '("-inbox" "-unread" "+archive")
        mail-signature +mail/signature
        mail-default-directory +mail/local-dir
        mail-source-directory +mail/local-dir
        message-signature +mail/signature
        message-auto-save-directory +mail/local-dir
        message-directory +mail/local-dir)

  (defun +mail/sync-mail ()
    "Sync mail via mbsync."
    (interactive)
    (start-process-shell-command "" nil "mbsync -a"))
  (defun +mail/trash-junk ()
    "Delete any mail in junk"
    (interactive)
    (start-process-shell-command "" nil "notmuch search --output=files --format=text0 tag:deleted tag:spam tag:trash tag:junk | xargs -r0 rm"))
  :config
  (defun +mail/flag-thread (&optional unflag beg end)
    (interactive (cons current-prefix-arg (notmuch-interactive-region)))
    (notmuch-search-tag
     (notmuch-tag-change-list '("-inbox" "+flagged") unflag) beg end)
    (when (eq beg end)
      (notmuch-search-next-thread)))
  (advice-add #'notmuch-poll-and-refresh-this-buffer :before
#'+mail/sync-mail)
  (advice-add #'notmuch-poll-and-refresh-this-buffer :after
#'+mail/trash-junk)
  (with-eval-after-load "evil-collection"
    (evil-collection-notmuch-setup)))
#+end_src
*** Smtpmail
#+begin_src emacs-lisp
(use-package smtpmail
  :after notmuch
  :commands mail-send
  :custom
  (smtpmail-smtp-server "mail.aryadevchavali.com")
  (smtpmail-smtp-user "aryadev")
  (smtpmail-smtp-service 587)
  (smtpmail-stream-type 'starttls)
  :init
  (setq send-mail-function #'smtpmail-send-it
        message-send-mail-function #'smtpmail-send-it))
#+end_src
** Dired
Setup for dired.  Make dired-hide-details-mode the default mode when
using dired-mode, as it removes the clutter.  Setup evil collection
for dired (even though dired doesn't really conflict with evil, there
are some corners I'd like to adjust).
#+begin_src emacs-lisp
(use-package dired
  :straight nil
  :commands (dired find-dired)
  :hook
  (dired-mode-hook              . auto-revert-mode)
  (dired-mode-hook              . dired-hide-details-mode)
  :init
  (setq-default dired-listing-switches "-AFBl --group-directories-first"
                dired-omit-files "^\\.")
  (with-eval-after-load "evil-collection"
    (evil-collection-dired-setup))
  :general
  (nmmap
    :keymaps 'dired-mode-map
    "T" #'dired-create-empty-file)
  (dir-leader
    "w" '(wdired-change-to-wdired-mode :which-key "Write dired")
    "f" #'find-dired
    "d" #'dired
    "D" #'dired-other-frame
    "p" `((proc (interactive)
                (dired "~/Text/PDFs/"))
          :which-key "Open PDFs"))
  :config
  (defun +dired/insert-all-subdirectories ()
    "Insert all subdirectories currently viewable."
    (interactive)
    (dired-mark-directories nil)
    (dolist #'dired-insert-subdir (dired-get-marked-files))
    (dired-unmark-all-marks))

  (nmmap
    :keymaps 'dired-mode-map
    "SPC"   nil
    "SPC ," nil)

  (local-leader
    :keymaps 'dired-mode-map
    "l" #'dired-maybe-insert-subdir
    "m" #'dired-mark-files-regexp
    "u" #'dired-undo))
#+end_src

*** fd-dired
Uses fd for finding file results in a directory: ~find-dired~ ->
~fd-dired~.

#+begin_src emacs-lisp
(use-package fd-dired
  :after dired
  :straight t
  :general
  (dir-leader
    "g" #'fd-dired))
#+end_src
** Xwidget
Xwidget is a package which allows for the insertion of arbitrary
xwidgets into Emacs through buffers.  It must be compiled into Emacs
so you might need to customise your install.  One of its premier uses
is in navigating the web which it provides through the function
~xwidget-webkit-browse-url~.  This renders a fully functional web
browser within Emacs.

Though I am not to keen on using Emacs to browse the web /via/ xwidget
(EWW does a good job on its own), I am very interested in its
capability to render pages with JavaScript, as it may come of use when
doing web development.  I can see the results of work very quickly
without switching windows all within Emacs.
*** Xwidget Core
#+begin_src emacs-lisp
(use-package xwidget
  :straight nil
  :display
  ("\\*xwidget.*"
   (display-buffer-pop-up-frame))
  :general
  (app-leader
    "u" #'xwidget-webkit-browse-url)
  (nmmap
    :keymaps 'xwidget-webkit-mode-map
    "q"         #'quit-window
    "h"         #'xwidget-webkit-scroll-backward
    "j"         #'xwidget-webkit-scroll-up
    "k"         #'xwidget-webkit-scroll-down
    "l"         #'xwidget-webkit-scroll-forward
    "+"         #'xwidget-webkit-zoom-in
    "-"         #'xwidget-webkit-zoom-out
    (kbd "C-f") #'xwidget-webkit-scroll-up
    (kbd "C-b") #'xwidget-webkit-scroll-down
    "H"         #'xwidget-webkit-back
    "L"         #'xwidget-webkit-forward
    "gu"        #'xwidget-webkit-browse-url
    "gr"        #'xwidget-webkit-reload
    "gg"        #'xwidget-webkit-scroll-top
    "G"         #'xwidget-webkit-scroll-bottom))
#+end_src
*** Xwidget Extensions
Define a function ~+xwidget/render-file~ that reads a file name and
presents it in an xwidget.  If the current file is an HTML file, ask
if user wants to open current file.  Bind it to ~aU~ in the leader.

Also define a function ~+xwidget/search-query~ that first asks the
user what search engine they want to use ([[https://duckduckgo.com][Duck Duck Go]] and [[https://devdocs.io][DevDocs]]
currently) then asks for a query, which it parses then presents in an
xwidget window.  Bind to ~as~ in the leader.
#+begin_src emacs-lisp
(use-package xwidget
  :straight nil
  :commands (+xwidget/render-file +xwidget/search)
  :general
  (app-leader
    "U" #'+xwidget/render-file
    "s" #'+xwidget/search)
  :config
  (setenv "WEBKIT_FORCE_SANDBOX" "0")
  (defun +xwidget/render-file (&optional FORCE)
    "Find file (or use current file) and render in xwidget."
    (interactive)
    (cond
     ((and (not FORCE) (or (string= (replace-regexp-in-string ".*.html"
                                                              "html" (buffer-name)) "html")
                           (eq major-mode 'web-mode)
                           (eq major-mode 'html-mode))) ; If in html file
      (if (y-or-n-p "Open current file?: ") ; Maybe they want to open a separate file
          (xwidget-webkit-browse-url (format "file://%s" (buffer-file-name)))
        (+xwidget/render-file t))) ; recurse and open file via prompt
     (t
      (xwidget-webkit-browse-url
       (format "file://%s" (read-file-name "Enter file to open: "))))))

  (defun +xwidget/search ()
    "Run a search query on some search engine and display in
xwidget."
    (interactive)
    (let* ((engine (completing-read "Engine: " '("duckduckgo.com" "devdocs.io") nil t))
           (query-raw (read-string "Enter query: "))
           (query
            (cond
             ((string= engine "duckduckgo.com") query-raw)
             ((string= engine "devdocs.io") (concat "_ " query-raw)))))
      (xwidget-webkit-browse-url (concat "https://" engine "/?q=" query)))))
#+end_src
** Eshell
*** Why Eshell?
Eshell is an integrated shell environment for Emacs, written in Emacs
Lisp.  I argue that it is the best shell/command interpreter to use in
Emacs.

Eshell is unlike the alternatives in Emacs as it's a /shell/ first,
not a terminal emulator. It has the ability to spoof some aspects of a
terminal emulator (through the shell parser), but it is NOT a terminal
emulator.

The killer benefits of eshell (which would appeal to Emacs users) are
a direct result of eshell being written in Emacs lisp:
- incredible integration with Emacs utilities (such as ~dired~,
  ~find-file~, any read functions, to name a few)
- very extensible, easy to write new commands which leverage Emacs
  commands as well as external utilities
- agnostic of platform: "eshell/cd" will call the underlying change
  directory function for you, so commands will (usually) mean the same
  thing regardless of platform
  - this means as long as Emacs runs, you can run eshell

However, my favourite feature of eshell is the set of evaluators that
run on command input.  Some of the benefits listed above come as a
result of this powerful feature. These evaluators are described below.

Lisp evaluator: works on braced expressions, evaluating them as Lisp
expressions (e.g. ~(message "Hello, World!\n")~).  Any returned
objects are printed.  This makes eshell a LISP REPL!

External evaluator: works within curly braces, evaluating them via
some external shell process (like sh) (e.g. ~{echo "Hello,
world!\n"}~).  This makes eshell a (kinda dumb) terminal emulator!

The alias evaluator is the top level evaluator.  It is the main
evaluator for each expression given to eshell.  When given an
expression it tries to evaluate it by testing against these conditions:
- it's an alias defined by the user or in the ~eshell/~ namespace of
  functions (simplest evaluator)
- it's some form of lisp expression (lisp evaluator)
- it's an external command (bash evaluator)
Essentially, you get the best of both Emacs and external shell
programs *ALL WITHIN* Emacs for free.
*** Eshell functionality
Bind some evil-like movements for easy shell usage, and a toggle
function to pull up the eshell quickly.
#+begin_src emacs-lisp
(use-package eshell
  :commands +shell/toggle-eshell
  :general
  (shell-leader
    "t" #'+shell/toggle-eshell)
  :init
  (add-hook
   'eshell-mode-hook
   (proc
    (interactive)
    (general-def
      :states '(normal insert)
      :keymaps 'eshell-mode-map
      "M-l" (proc (interactive) (eshell/clear)
                  "M-j" #'eshell-next-matching-input-from-input
                  "M-k" #'eshell-previous-matching-input-from-input)
      (local-leader
        :keymaps 'eshell-mode-map
        "c" (proc (interactive) (eshell/clear)
                  (recenter))
        "k" #'eshell-kill-process))))
  :config
  (+oreo/create-toggle-function
   +shell/toggle-eshell
   "*eshell*"
   eshell
   t))
#+end_src
*** Eshell pretty symbols and display
Pretty symbols and a display record.
#+begin_src emacs-lisp
(use-package eshell
  :defer t
  :pretty
  (eshell-mode-hook
   ("lambda"  . "λ")
   ("numberp" . "ℤ")
   ("t"       . "⊨")
   ("nil"     . "Ø"))
  :display
  ("\\*e?shell\\*" ; for general shells as well
   (display-buffer-at-bottom)
   (window-height . 0.25)))
#+end_src
*** Eshell variables and aliases
Set some sane defaults, a banner and a prompt.  The prompt checks for
a git repo in the current directory and provides some extra
information in that case (in particular, branch name and if there any
changes that haven't been committed).

Also add ~eshell/goto~, which is actually a command accessible from
within eshell (this is because ~eshell/*~ creates an accessible
function within eshell with name ~*~).  ~eshell/goto~ makes it easier
to change directories by using Emacs' find-file interface (which is
much faster than ~cd ..; ls -l~).
#+begin_src emacs-lisp
(use-package eshell
  :config
  (defun +eshell/get-git-properties ()
    (let* ((git-branch (shell-command-to-string "git branch"))
           (is-repo (string= (if (string= git-branch "") ""
                               (substring git-branch 0 1)) "*")))
      (if (not is-repo) ""
        (concat
         "("
         (nth 2 (split-string git-branch "\n\\|\\*\\| "))
         "<"
         (if (string= "" (shell-command-to-string "git status | grep 'up to date'"))
             "×"
           "✓")
         ">)"))))
  (setq eshell-cmpl-ignore-case t
        eshell-cd-on-directory t
        eshell-banner-message (concat (shell-command-to-string "figlet eshell") "\n")
        eshell-prompt-function
        (proc
         (let ((properties (+eshell/get-git-properties)))
           (concat
            properties
            (format "[%s]\n" (abbreviate-file-name (eshell/pwd)))
            "λ ")))
        eshell-prompt-regexp "^λ ")

  (defun eshell/goto (&rest args)
    "Use `read-directory-name' to change directories."
    (eshell/cd (list (read-directory-name "Enter directory to go to:")))))
#+end_src
*** Eshell change directory quickly
~eshell/goto~ is a better ~cd~ for eshell.  However it is really just
a plaster over a bigger issue for my workflow; many times I want
eshell to be present in the current directory of the buffer I am
using.

#+begin_src emacs-lisp
(use-package eshell
  :straight nil
  :general
  (shell-leader
    "T" #'+eshell/current-buffer)
  :config
  (defun +eshell/current-buffer ()
    (interactive)
    (let  ((dir (if buffer-file-name
                    (file-name-directory buffer-file-name)
                  (if default-directory
                      default-directory
                    nil)))
           (buf (eshell)))
      (if dir
          (with-current-buffer buf
            (eshell/cd dir)
            (eshell-send-input))
        (message "Could not switch eshell: buffer is not real file")))))
#+end_src
** Elfeed
Elfeed is the perfect RSS feed reader, integrated into Emacs
perfectly.  I've got a set of feeds that I use for a large variety of
stuff, mostly media and entertainment.  I've also bound "<leader> ar"
to elfeed for loading the system.
#+begin_src emacs-lisp
(use-package elfeed
  :general
  (app-leader "r" #'elfeed)
  (nmmap
    :keymaps 'elfeed-search-mode-map
    "gr"       #'elfeed-update
    "s"        #'elfeed-search-live-filter
    "<return>" #'elfeed-search-show-entry)
  :init
  (setq elfeed-db-directory (no-littering-expand-var-file-name "elfeed/"))
  (setq +rss/feed-urls
        '(("Arch Linux"
           "https://www.archlinux.org/feeds/news/"
           Linux)
          ("LEMMiNO"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UCRcgy6GzDeccI7dkbbBna3Q"
           YouTube Stories)
          ("The Onion"
           "https://www.theonion.com/rss"
           Social)
          ("Stack exchange"
           "http://morss.aryadevchavali.com/stackexchange.com/feeds/questions"
           Social)
          ("Dark Sominium"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UC_e39rWdkQqo5-LbiLiU10g"
           YouTube Stories)
          ("Dark Sominium Music"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UCkLiZ_zLynyNd5fd62hg1Kw"
           YouTube Music)
          ("Nexpo"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UCpFFItkfZz1qz5PpHpqzYBw"
           YouTube)
          ("Techquickie"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UC0vBXGSyV14uvJ4hECDOl0Q"
           YouTube)
          ("3B1B"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UCYO_jab_esuFRV4b17AJtAw"
           YouTube)
          ("Fredrik Knusden"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UCbWcXB0PoqOsAvAdfzWMf0w"
           YouTube Stories)
          ("Barely Sociable"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UC9PIn6-XuRKZ5HmYeu46AIw"
           YouTube Stories)
          ("Atrocity Guide"
           "https://www.youtube.com/feeds/videos.xml?channel_id=UCn8OYopT9e8tng-CGEWzfmw"
           YouTube Stories)
          ("Hacker News"
           "http://morss.aryadevchavali.com/news.ycombinator.com/rss"
           Social)
          ("Hacker Factor"
           "https://www.hackerfactor.com/blog/index.php?/feeds/index.rss2"
           Social)
          ("BBC Top News"
           "http://morss.aryadevchavali.com/feeds.bbci.co.uk/news/rss.xml"
           News)
          ("BBC Tech News"
           "http://morss.aryadevchavali.com/feeds.bbci.co.uk/news/technology/rss.xml"
           News)))
  :config
  (with-eval-after-load "evil-collection"
    (evil-collection-elfeed-setup))
  (setq elfeed-feeds (cl-map 'list #'(lambda (item)
                                       (append (list (nth 1 item)) (cdr (cdr item))))
                             +rss/feed-urls)))
#+end_src
** Magit
Magit is *the* git porcelain for Emacs, which perfectly encapsulates
the git cli.  In this case I just need to setup the bindings for it.
As magit will definitely load after evil (as it must be run by a
binding, and evil will load after init), I can use evil-collection
freely.  Also, define an auto insert for commit messages so that I
don't need to write everything myself.

#+begin_src emacs-lisp
(use-package magit
  :defer t
  :display
  ("magit:.*"
   (display-buffer-same-window)
   (inhibit-duplicate-buffer . t))
  ("magit-diff:.*"
   (display-buffer-below-selected))
  ("magit-log:.*"
   (display-buffer-same-window))
  :general
  (leader
    "g" '(magit-status :which-key "Magit"))
  (code-leader
    "b" #'magit-blame)
  :auto-insert
  (("COMMIT_EDITMSG" . "Commit skeleton")
   ""
   "(" (read-string "Enter feature/module: ") ")"
   (read-string "Enter simple description: ") "\n\n")
  :init
  (setq vc-follow-symlinks t
        magit-blame-echo-style 'lines)
  :config
  (with-eval-after-load "evil"
    (evil-set-initial-state 'magit-status-mode 'motion))
  (with-eval-after-load "evil-collection"
    (evil-collection-magit-setup)))
#+end_src
** IBuffer
#+begin_src emacs-lisp
(use-package ibuffer
  :general
  (buffer-leader
    "i" #'ibuffer)
  :config
  (with-eval-after-load "evil-collection"
    (evil-collection-ibuffer-setup)))
#+end_src
** Processes
Emacs has two systems for process management:
+ proced: a general 'top' like interface which allows general
  management of linux processes
+ list-processes: a specific Emacs based system that lists processes
  spawned by Emacs (similar to a top for Emacs specifically)

*** Proced
Core proced config, just a few bindings and evil collection setup.
#+begin_src emacs-lisp
(use-package proced
  :straight nil
  :general
  (app-leader
    "p" #'proced)
  (nmap
    :keymaps 'proced-mode-map
    "za" #'proced-toggle-auto-update)
  :display
  ("\\*Proced\\*"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :init
  (setq proced-auto-update-interval 0.5)
  :config
  (with-eval-after-load "evil-collection"
    (evil-collection-proced-setup)))
#+end_src

Along with that I setup the package ~proced-narrow~ which allows
further filtering of the process list.
#+begin_src emacs-lisp
(use-package proced-narrow
  :straight t
  :after proced
  :general
  (nmap
    :keymaps 'proced-mode-map
    "%" #'proced-narrow))
#+end_src
** Calculator
Surprise, surprise Emacs comes with a calculator.

Greater surprise, this thing is over powered.  It can perform the
following (and more):
- Matrix calculations
- Generalised calculus operations
- Equation solvers for n-degree multi-variable polynomials
- Embedded mode (check below)!

~calc-mode~ is a calculator system within Emacs that provides a
diverse array of mathematical operations.  It uses reverse polish
notation to do calculations (though there is a standard infix
algebraic notation mode).

Embedded mode allows computation with the current buffer as the echo
area.  This basically means I can compute stuff within a buffer
without invoking calc directly: $1 + 2\rightarrow_{\text{calc-embed}} 3$.

#+begin_src emacs-lisp
(use-package calc
  :straight nil
  :display
  ("*Calculator*"
   (display-buffer-at-bottom)
   (window-height . 0.18))
  :general
  (app-leader
    "c" #'calc-dispatch)
  (mode-leader
    "c" #'calc-embedded)
  :init
  (setq calc-algebraic-mode t)
  :config
  (with-eval-after-load "evil-collection"
    (evil-collection-calc-setup)))
#+end_src
*** WIP Calctex
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
~calc-mode~ also has a 3rd party package called ~calctex~. It renders
mathematical expressions within calc as if they were rendered in TeX.
You can also copy the expressions in their TeX forms, which is pretty
useful when writing a paper.  I've set a very specific lock on this
repository as it's got quite a messy work-tree and this commit seems to
work for me given the various TeX utilities installed via Arch.

#+begin_src emacs-lisp
(use-package calctex
  :after calc
  :straight (calctex :type git :host github :repo "johnbcoughlin/calctex")
  :hook (calc-mode-hook . calctex-mode))
#+end_src
** Ledger
#+begin_src emacs-lisp
(use-package ledger-mode
  :defer t)

(use-package evil-ledger
  :after ledger-mode)
#+end_src
** WIP Zone
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Of course Emacs has a cool screensaver software.

#+begin_src emacs-lisp
(use-package zone-matrix
  :straight t
  :after dashboard
  :init
  (setq zone-programs
        [zone-pgm-jitter
         zone-pgm-putz-with-case
         zone-pgm-dissolve
         zone-pgm-whack-chars
         zone-pgm-drip
         zone-pgm-rat-race
         zone-pgm-random-life
         zone-matrix
         ])
  :config
  (zone-when-idle 15))
#+end_src
** (Wo)man
Man pages are the user manuals for most software on Linux.  Really
useful when writing code for Un*x systems, though they can be very
verbose.

2023-08-17: `Man-notify-method' is the reason the `:display' record
doesn't work here.  I think it's to do with how Man pages are rendered
or something, but very annoying as it's a break from standards!
#+begin_src emacs-lisp
(use-package man
  :demand t
  :straight nil
  :init
  (setq Man-notify-method 'pushy)
  :display
  ("^\\*Man.*"
   (display-buffer-reuse-mode-window)
   (display-buffer-same-window))
  :general
  (file-leader
    "m" #'man) ;; kinda like "find man page"
  (nmmap
    :keymaps 'Man-mode-map
    "RET" #'man-follow))
#+end_src
* Text modes
Standard packages and configurations for text-mode and its derived
modes.
** Flyspell
Flyspell allows me to quickly spell check text documents.  I use
flyspell primarily in org mode, as that is my preferred prose writing
software, but I also need it in commit messages and so on.  So
flyspell-mode should be hooked to text-mode.
#+begin_src emacs-lisp
(use-package flyspell
  :hook (text-mode-hook . flyspell-mode)
  :general
  (nmmap
    :keymaps 'text-mode-map
    (kbd "M-C") #'flyspell-correct-word-before-point
    (kbd "M-c") #'flyspell-auto-correct-word)
  (local-leader
    :keymaps 'flyspell-mode-map
    "S" #'flyspell-region)
  (mode-leader
    "s" #'flyspell-mode))
#+end_src
** Undo tree
Undo tree sits on top of the incredible Emacs undo capabilities.
Provides a nice visual for edits and a great way to produce branches
of edits.  Also allows saving of undo trees, which makes Emacs a quasi
version control system in and of itself!  The only extra necessary
would be describing changes...
#+begin_src emacs-lisp
(use-package undo-tree
  :straight t
  :hook (after-init-hook . global-undo-tree-mode)
  :init
  (setq undo-tree-auto-save-history t
        undo-tree-history-directory-alist backup-directory-alist)
  :general
  (leader
    "u" #'undo-tree-visualize))
#+end_src
** Whitespace
Deleting whitespace, highlighting when going beyond the 80th character
limit, all good stuff.  I don't want to highlight whitespace for
general mode categories (Lisp shouldn't really have an 80 character
limit), so set it for specific modes need the help.
#+begin_src emacs-lisp
(use-package whitespace
  :straight nil
  :general
  (nmmap
    "M--"   #'whitespace-cleanup)
  (mode-leader
    "w" #'whitespace-mode)
  :hook
  (before-save-hook  . whitespace-cleanup)
  (c-mode-hook       . whitespace-mode)
  (c++-mode-hook     . whitespace-mode)
  (haskell-mode-hook . whitespace-mode)
  (python-mode-hook  . whitespace-mode)
  (org-mode-hook     . whitespace-mode)
  (text-mode-hook    . whitespace-mode)
  :init
  (setq whitespace-style '(face lines-tail spaces tabs tab-mark trailing newline)
        whitespace-line-column 80))
#+end_src
** Set auto-fill-mode for all text-modes
Auto fill mode automatically newlines text on 80 characters, which
looks nice and integrates well with Evil's sentence and paragraph text
objects.
#+begin_src emacs-lisp
(add-hook 'text-mode-hook #'auto-fill-mode)
#+end_src
** Show-paren-mode
Show parenthesis for Emacs
#+begin_src emacs-lisp
(add-hook 'prog-mode-hook #'show-paren-mode)
#+end_src
** Smartparens
Smartparens is a smarter electric-parens, it's much more aware of
context and easier to use.
#+begin_src emacs-lisp
(use-package smartparens
  :hook
  (prog-mode-hook . smartparens-mode)
  (text-mode-hook . smartparens-mode)
  :after evil
  :config
  (setq sp-highlight-pair-overlay nil
        sp-highlight-wrap-overlay t
        sp-highlight-wrap-tag-overlay t)

  (let ((unless-list '(sp-point-before-word-p
                       sp-point-after-word-p
                       sp-point-before-same-p)))
    (sp-pair "'"  nil :unless unless-list)
    (sp-pair "\"" nil :unless unless-list))
  (sp-local-pair sp-lisp-modes "(" ")" :unless '(:rem sp-point-before-same-p))
  (require 'smartparens-config))
#+end_src
** Thesaurus
=le-thesaurus= is a great extension for quickly searching up words for
synonyms or antonyms.  I may need it anywhere so I bind it to all
keymaps.
#+begin_src emacs-lisp
(use-package le-thesaurus
  :straight t
  :general
  (local-leader
    :keymaps 'override
    "[" #'le-thesaurus-get-synonyms
    "]" #'le-thesaurus-get-antonyms))
#+end_src
** Licensing
Defines an auto-insert for LICENSE files.  NOTE: The LICENSE is
MIT, but I might change that.
#+begin_src emacs-lisp
(use-package emacs
  :straight nil
  :auto-insert
  (("LICENSE" . "MIT License")
   ""
   "MIT License

Copyright (c) 2023 Aryadev Chavali

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the \"Software\"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE."))
#+end_src
* Programming packages
Packages that help with programming in general, providing IDE like
capabilities.
** Eldoc
Eldoc presents documentation to the user upon placing ones cursor upon
any symbol.  This is very useful when programming as it:
- presents the arguments of functions while writing calls for them
- presents typing and documentation of variables

Eldoc box makes the help buffer a hovering box instead of printing it
in the minibuffer.  A lot cleaner.
#+begin_src emacs-lisp
(use-package eldoc
  :straight nil
  :hook (prog-mode-hook . eldoc-mode)
  :init
  (global-eldoc-mode 1))

(use-package eldoc-box
  :hook (eldoc-mode-hook . eldoc-box-hover-mode)
  :init
  (setq eldoc-box-position-function #'eldoc-box--default-upper-corner-position-function
        eldoc-box-clear-with-C-g t))
#+end_src
** Eglot
Eglot is package to communicate with LSP servers for better
programming capabilities.  Interactions with a server provide results
to the client, done through JSON.

NOTE: Emacs 28.1 comes with better JSON parsing, which makes Eglot
much faster.

2023-03-26: I've found Eglot to be useful sometimes, but many of the
projects I work on don't require a heavy server setup to efficiently
edit and check for errors; Emacs provides a lot of functionality.  So
by default I've disabled it, using =M-x eglot= to startup the LSP
server when I need it.
#+begin_src emacs-lisp
(use-package eglot
  :after project
  :defer t
  :general
  (code-leader
    :keymaps 'eglot-mode-map
    "f" #'eglot-format
    "a" #'eglot-code-actions
    "r" #'eglot-rename
    "R" #'eglot-reconnect)
  ;; :init
  ;; (setq eglot-stay-out-of '(flymake))
  :config
  (add-to-list 'eglot-server-programs '((c++-mode c-mode) "clangd")))
#+end_src
** Flycheck
Flycheck is the checking system for Emacs.  I don't necessarily like
having all my code checked all the time, so I haven't added a hook to
prog-mode as it would be better for me to decide when I want checking
and when I don't.
#+begin_src emacs-lisp
(use-package flycheck
  :commands (flycheck-mode flycheck-list-errors)
  :hook
  (c-mode-hook   . flycheck-mode)
  (c++-mode-hook . flycheck-mode)
  :general
  (mode-leader
    "f" #'flycheck-mode)
  (code-leader
    "x" #'flycheck-list-errors
    "J" #'flycheck-next-error
    "K" #'flycheck-previous-error)
  :display
  ("\\*Flycheck.*"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :config
  (with-eval-after-load "evil-collection"
    (evil-collection-flycheck-setup)))
#+end_src
** Tabs and spaces
By default, turn off tabs and set the tab width to two.
#+begin_src emacs-lisp
(setq-default indent-tabs-mode nil
              tab-width 2)
#+end_src

However, if necessary later, define a function that may activate tabs locally.
#+begin_src emacs-lisp
(defun +oreo/activate-tabs ()
  (interactive)
  (setq-local indent-tabs-mode t))
#+end_src
** Highlight todo items
TODO items are highlighted in org-mode, but not necessarily in every
mode.  This minor mode highlights all TODO like items via a list of
strings to match.  It also configures faces to use when highlighting.
I hook it to prog-mode.

#+begin_src emacs-lisp
(use-package hl-todo
  :after prog-mode
  :hook (prog-mode-hook . hl-todo-mode)
  :init
  (setq hl-todo-keyword-faces
        '(("TODO"  . "#E50000")
          ("WIP"   . "#ffa500")
          ("NOTE"  . "#00CC00")
          ("FIXME" . "#d02090"))))
#+end_src
** Hide-show mode
Turn on ~hs-minor-mode~ for all prog-mode.  This provides folds for
free.
#+begin_src emacs-lisp
(use-package hideshow
  :straight nil
  :hook (prog-mode-hook . hs-minor-mode))
#+end_src
** Aggressive indenting
Essentially my dream editing experience: when I type stuff in, try and
indent it for me on the fly.  Just checkout the
[[https://github.com/Malabarba/aggressive-indent-mode][page]], any
description I give won't do it justice.

#+begin_src emacs-lisp
(use-package aggressive-indent
  :straight t
  :demand t
  :config
  (add-to-list 'aggressive-indent-excluded-modes
               'c-mode)
  (add-to-list 'aggressive-indent-excluded-modes
               'c++-mode)
  (add-to-list 'aggressive-indent-excluded-modes
               'cc-mode)
  (global-aggressive-indent-mode))
#+end_src
** Compilation
Colourising the compilation buffer so ANSI colour codes get computed.
#+begin_src emacs-lisp
(use-package compile
  :straight nil
  :general
  (code-leader
    "j" #'next-error
    "k" #'previous-error
    "c" #'compile
    "C" #'recompile)
  (nmmap
    :keymaps 'compilation-mode-map
    "g" #'recompile)
  :display
  ("\\*compilation\\*"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :config
  (defun +compile/colourise ()
    "Colourise the emacs compilation buffer."
    (interactive)
    (let ((inhibit-read-only t))
      (ansi-color-apply-on-region (point-min) (point-max))))
  (add-hook 'compilation-filter-hook #'+compile/colourise))
#+end_src
** Makefile
Defines an auto-insert for Makefiles.  Assumes C but it's very easy to
change it for C++.
#+begin_src emacs-lisp
(use-package emacs
  :auto-insert
  (("[mM]akefile\\'" . "Makefile skeleton")
   ""
   "CC=gcc
CFLAGS=-Wall -Wextra -Wpedantic -ggdb -fsanitize=address -std=c11
LIBS=
OBJECTS=main.o
OUT=main
ARGS=

%.o: %.c
	$(CC) $(CFLAGS) -c $^ -o $@ $(LIBS)

$(OUT): $(OBJECTS)
	$(CC) $(CFLAGS) $^ -o $@ $(LIBS)

.PHONY:
clean:
	rm -rfv $(OUT) $(OBJECTS)

.PHONY: run
run: $(OUT)
	./$^ $(ARGS)"
   _))
#+end_src
* Org mode
2023-03-30: finally decided to give org mode its own section.

Org is, at its most basic, a markup language.  Files use the ".org"
extension and use =org-mode= to write text, with the ability to export
to a few formats, all within Emacs.  Some other features include:
+ A complete spreadsheet system, with formulas (including
  [[*Calculator][calc-mode]] integration)
+ Evaluation of code blocks, even using the results of them in exports
  (to, say, a $\LaTeX$ or HTML document)
  + This includes exporting code blocks to a code file.  All the
    emacs-lisp code blocks in this file are compiled to =config.el=
    ([[file:elisp/literate.el][literate]])
+ Complete calendar/todo system with deadlines, scheduling and
  repeaters
+ Export to a variety of formats or make your own export engine using
  the org AST!
  + Writing latex in document, with ability to render them on demand,
    and exporting to PDFs through Latex
** Org Essentials
Org has a ton of settings to tweak, which change your experience quite
a bit.  My setup should be as portable as possible and (/sometimes/) I
need to access org mode files in other editors, so org files should be
as close to clear text as possible.  This is the guiding philosophy
that essentially makes most of my options pretty immediate.

Some arbitrary notes:
+ By default =~/Text= is my directory for text files.  I actually have
  a repository that manages this directory for agenda files and other
  documents
+ Indentation in file should not be allowed, i.e. text indentation,
  as that forces other editors to read it a certain way as well.  It
  seems obtrusive hence it's off.
+ Org startup indented is on by default as most documents do benefit
  from the indentation, but I do turn it off for some files via
  ~#+startup:noindent~
+ When opening an org document there can be a lot of headings, so I
  set folding to just content
+ Org documents can also have a lot of latex previews, which make
  opening some after a while a massive hassle.  If I want to see the
  preview, I'll do it myself, so turn it off.
+ Org manages windowing itself, to some extent, so I set those options
  to be as unobtrusive as possible

#+begin_src emacs-lisp
(use-package org
  :defer t
  :straight t
  :init
  (setq
   org-directory "~/Text"
   org-adapt-indentation nil
   org-indent-mode nil
   org-startup-indented t
   org-startup-folded 'content
   org-startup-with-latex-preview nil
   org-imenu-depth 10
   org-src-window-setup 'current-window
   org-indirect-buffer-display 'current-window
   org-link-frame-setup '((vm . vm-visit-folder-other-frame)
                          (vm-imap . vm-visit-imap-folder-other-frame)
                          (file . find-file))))
#+end_src
** Org Latex
Org mode has deep integration with latex, can export to PDF and even
display latex fragments in the document directly.  I setup the
pdf-process, code listing options via minted and the format options
for latex fragments.
#+begin_src emacs-lisp
(use-package org
  :defer t
  :init
  (setq org-format-latex-options '(:foreground default :background default :scale 2
                                   :html-foreground "Black" :html-background "Transparent"
                                   :html-scale 1.0 :matchers ("begin" "$1" "$" "$$" "\\(" "\\["))
        org-latex-src-block-backend 'minted
        org-latex-minted-langs '((emacs-lisp "common-lisp")
                                 (ledger "text")
                                 (cc "c++")
                                 (cperl "perl")
                                 (shell-script "bash")
                                 (caml "ocaml"))
        org-latex-packages-alist '(("" "minted"))
        org-latex-pdf-process
        '("latexmk -pdfxe -bibtex -f -shell-escape %f")
        org-latex-minted-options '(("style" "colorful")
                                   ("linenos")
                                   ("frame" "single")
                                   ("mathescape")
                                   ("fontfamily" "courier")
                                   ("samepage" "false")
                                   ("breaklines" "true")
                                   ("breakanywhere" "true"))))
#+end_src
** Org Core Variables
Tons of variables for org-mode, including a ton of latex ones.  Can't
really explain because it sets up quite a lot of local stuff.  Also I
copy pasted the majority of this, tweaking it till it felt good.  Doom
Emacs was very helpful here.
#+begin_src emacs-lisp
(use-package org
  :init
  (setq org-edit-src-content-indentation 0
        org-goto-interface 'outline
        org-imenu-depth 10
        org-export-backends '(ascii html latex odt icalendar)
        org-eldoc-breadcrumb-separator " → "
        org-enforce-todo-dependencies t
        org-fontify-quote-and-verse-blocks t
        org-fontify-whole-heading-line t
        org-footnote-auto-label t
        org-hide-leading-stars t
        org-hide-emphasis-markers nil
        org-image-actual-width nil
        org-priority-faces '((?A . error) (?B . warning) (?C . success))
        org-link-descriptive nil
        org-tags-column 0
        org-todo-keywords
        '((sequence "TODO" "WIP" "DONE")
          (sequence "PROJ" "WAIT" "COMPLETE"))
        org-use-sub-superscripts '{}
        org-babel-load-languages '((emacs-lisp . t)
                                   (lisp . t)
                                   (shell . t))))
#+end_src
** Org Core Functionality
Hooks, prettify-symbols and records for auto insertion.
#+begin_src emacs-lisp
(use-package org
  :hook
  (org-mode-hook . prettify-symbols-mode)
  :display
  ("\\*Org Src.*"
   (display-buffer-same-window))
  :pretty
  (org-mode-hook
   ("#+begin_src" . "≫")
   ("#+end_src"   . "≪"))
  :init
  (with-eval-after-load "autoinsert"
    (define-auto-insert '("\\.org\\'" . "Org skeleton")
      '("Enter title: "
        "#+title: " str | (buffer-file-name) "\n"
        "#+author: " (read-string "Enter author: ") | user-full-name "\n"
        "#+description: " (read-string "Enter description: ") | "Description" "\n"
        "#+date: " (format-time-string "%Y-%m-%d" (current-time)) "\n"
        "* " _))))
#+end_src
** Org Core Bindings
Some bindings for org mode.
#+begin_src emacs-lisp
(use-package org
  :after counsel
  :config
  (defun +org/swiper-goto ()
    (interactive)
    (swiper "^\\* "))
  :general
  (file-leader
    "l" #'org-store-link
    "i" #'org-insert-last-stored-link)
  (code-leader
    "D" #'org-babel-detangle)
  (nmmap
    :keymaps 'org-mode-map
    [remap imenu] #'+org/swiper-goto)
  (local-leader
    :keymaps 'org-mode-map
    "l" '(nil :which-key "Links")
    "'" '(nil :which-key "Tables")
    "c" '(nil :which-key "Clocks"))
  (local-leader
    :keymaps 'org-mode-map
    :infix "l"
    "i" #'org-insert-link
    "l" #'org-open-at-point
    "f" #'org-footnote-action)
  (local-leader
    :keymaps 'org-mode-map
    :infix "'"
    "a" #'org-table-align
    "f" #'org-table-edit-formulas
    "t" #'org-table-toggle-coordinate-overlays
    "s" #'org-table-sum
    "e" #'org-table-calc-current-TBLFM
    "E" #'org-table-eval-formula)
  (local-leader
    :keymaps 'org-mode-map
    :infix "c"
    "i" #'org-clock-clock-in
    "o" #'org-clock-clock-out
    "c" #'org-clock-in-last
    "d" #'org-clock-display)
  (local-leader
    :keymaps 'org-mode-map
    "d" #'org-date-from-calendar
    "t" #'org-todo
    "," #'org-priority
    "T" #'org-babel-tangle
    "i" #'org-insert-structure-template
    "p" #'org-latex-preview
    "s" #'org-property-action
    "e" #'org-export-dispatch
    "o" #'org-edit-special))
#+end_src
** Org Agenda
Org agenda provides a nice viewing for schedules.  With org mode it's
a very tidy way to manage your time.
#+begin_src emacs-lisp
(use-package org-agenda
  :after org
  :straight nil
  :init
  (defconst +org/agenda-root "~/Text"
    "Root directory for all agenda files")
  (setq org-agenda-files (list (expand-file-name +org/agenda-root))
        org-agenda-window-setup 'current-window
        org-agenda-skip-deadline-prewarning-if-scheduled t
        org-agenda-skip-scheduled-if-done t
        org-agenda-skip-deadline-if-done t
        org-agenda-start-with-entry-text-mode nil)
  :config
  (evil-set-initial-state 'org-agenda-mode 'normal)
  :general
  (file-leader
    "a" `(,(proc (interactive)
                 (find-file (completing-read "Enter directory: " org-agenda-files nil t)))
          :which-key "Open agenda directory"))

  (app-leader
    "a" #'org-agenda)

  (nmmap
    :keymaps 'org-agenda-mode-map
    "zd" #'org-agenda-day-view
    "zw" #'org-agenda-week-view
    "zm" #'org-agenda-month-view
    "gd" #'org-agenda-goto-date
    "RET" #'org-agenda-switch-to
    "J" #'org-agenda-later
    "K" #'org-agenda-earlier
    "t" #'org-agenda-todo
    "." #'org-agenda-goto-today
    "," #'org-agenda-goto-date
    "q" #'org-agenda-quit
    "r" #'org-agenda-redo))
#+end_src
** Org capture
#+begin_src emacs-lisp
(use-package org-capture
  :straight nil
  :init
  (setq
   org-capture-templates
   '(("t" "A todo" entry
      (file "")
      "* TODO %?
%T
%a"))
   org-default-notes-file (concat org-directory "/todo.org"))
  :general
  (file-leader
    "w" #'org-capture))
#+end_src
** Org clock-in
Org provides a nice timekeeping system that allows for managing how
much time is taken per task.  It even has an extensive reporting
system to see how much time you spend on specific tasks or overall.
#+begin_src emacs-lisp
(use-package org-clock
  :after org
  :straight nil
  :init
  (defvar +org/clock-out-toggle-report nil
    "Non-nil means update the first clock report in the file every
time a clock out occurs.")
  :config
  (advice-add #'org-clock-out
              :after
              (proc (interactive)
                    (if +org/clock-out-toggle-report
                        (org-clock-report t))))
  :general
  (local-leader
    :keymaps 'org-mode-map
    :infix "c"
    "c" #'org-clock-in
    "o" #'org-clock-out
    "r" #'org-clock-report
    "t" (proc (interactive)
              (setq-local +org/clock-out-toggle-report
                          (not +org/clock-out-toggle-report)))))
#+end_src
** Org on save
If ~+org/compile-to-pdf-on-save-p~ is non-nil, then compile to
\(\LaTeX\) and run an async process to compile it to a PDF.  Doesn't
make Emacs hang (like ~org-latex-export-to-pdf~) and doesn't randomly
crash (like the async handler for org-export).  Works really well with
~pdf-view-mode~.
#+begin_src emacs-lisp
(use-package org
  :defer t
  :init
  (defvar +org/compile-to-pdf-on-save-p
    nil
    "Non-nil to activate compile functionality.")
  :general
  (local-leader
    :keymaps 'org-mode-map
    "C" (proc (interactive)
              (if (+org/compile-to-pdf-on-save-f)
                  (setq-local +org/compile-to-pdf-on-save-p nil)
                (setq-local +org/compile-to-pdf-on-save-p t))))
  :config
  (+oreo/create-auto-save
   (and (eq major-mode 'org-mode) +org/compile-to-pdf-on-save-p)
   (start-process-shell-command "" "*pdflatex*" (concat "pdflatex -shell-escape "
                                                        (org-latex-export-to-latex)))))
#+end_src
** Org ref
For bibliographic stuff in $\LaTeX$ export.
#+begin_src emacs-lisp
(use-package org-ref
  :straight t
  :defer t
  :init
  (setq bibtex-files '("~/Text/bibliography.bib")
        bibtex-completion-bibliography '("~/Text/bibliography.bib")
        bibtex-completion-additional-search-fields '(keywords)))
#+end_src
*** Org ref ivy integration
Org ref requires ivy-bibtex to work properly with ivy, so we need to
set that up as well
#+begin_src emacs-lisp
(use-package ivy-bibtex
  :straight t
  :after org-ref
  :config
  (require 'org-ref-ivy))
#+end_src
** Org message
Org message allows for the use of org mode when composing mails,
generating HTML multipart emails.  This integrates the WYSIWYG
experience with mail in Emacs while also providing powerful text
features with basically no learning curve (as long as you've already
learnt the basics of org).

#+begin_src emacs-lisp
(use-package org-msg
  :hook (message-mode-hook . org-msg-mode)
  :config
  (setq org-msg-options "html-postamble:nil H:5 num:nil ^:{} toc:nil author:nil email:nil \\n:t tex:dvipng"
        org-msg-greeting-name-limit 3)

  (add-to-list 'org-msg-enforce-css
               '(img latex-fragment-inline
                     ((transform . ,(format "translateY(-1px) scale(%.3f)"
                                            (/ 1.0 (if (boundp 'preview-scale)
                                                       preview-scale 1.4))))
                      (margin . "0 -0.35em")))))
#+end_src
** Org for evil
Evil org for some nice bindings.
#+begin_src emacs-lisp
(use-package evil-org
  :hook (org-mode-hook . evil-org-mode))
#+end_src
** Org reveal
Org reveal allows one to export org files as HTML presentations via
reveal.js.  Pretty nifty and it's easy to use.
#+begin_src emacs-lisp
(use-package ox-reveal
  :defer t
  :init
  (setq org-reveal-root "https://cdn.jsdelivr.net/npm/reveal.js"
        org-reveal-theme "sky"))
#+end_src
** Org fragtog
Toggle latex fragments in org mode so you get fancy maths symbols.  I
use latex a bit in org mode as it is the premier way of getting
mathematical symbols rendered, but org mode > latex.

Delimited environments are aplenty, escaped brackets and dollar signs
are my favourite.  Here's a snippet:
$\int_{-\infty}^{\infty}e^{-x^2}dx = \sqrt{\pi}$.
#+begin_src emacs-lisp
(use-package org-fragtog
  :hook (org-mode-hook . org-fragtog-mode))
#+end_src
** Org superstar
Org superstar adds unicode symbols for headers, much better than the
default asterisks.
#+begin_src emacs-lisp
(use-package org-superstar
  :hook (org-mode-hook . org-superstar-mode))
#+end_src
* Languages
Configuration for specific languages or file formats.
** PDF
I use PDFs mostly for reading reports or papers.  Though Emacs isn't
my preferred application for viewing PDFs (I highly recommend
[[https://pwmt.org/projects/zathura/][Zathura]]), similar to most things with Emacs, having a PDF viewer
builtin can be a very useful asset.

For example if I were editing an org document which I was eventually
compiling into a PDF, my workflow would be much smoother with a PDF
viewer within Emacs that I can open on another pane.
*** PDF tools
~pdf-tools~ provides the necessary functionality for viewing PDFs.
There is no proper PDF viewing without this package.
~evil-collection~ provides a setup for this mode, so use that.
#+begin_src emacs-lisp
(use-package pdf-tools
  :mode ("\\.[pP][dD][fF]\\'" . pdf-view-mode)
  :straight t
  :display
  ("^.*pdf$"
   (display-buffer-same-window)
   (inhibit-duplicate-buffer . t))
  :config
  (pdf-tools-install-noverify)
  (with-eval-after-load "evil-collection"
    (evil-collection-pdf-setup)))
#+end_src
*** PDF grep
PDF grep is a Linux tool that allows for searches against the text
inside of PDFs similar to standard grep.  This cannot be performed by
standard grep due to how PDFs are encoded; they are not a clear text
format.
#+begin_src emacs-lisp
(use-package pdfgrep
  :after pdf-tools
  :hook (pdf-view-mode-hook . pdfgrep-mode)
  :general
  (nmap
    :keymaps 'pdf-view-mode-map
    "M-g"    #'pdfgrep))
#+end_src
** SQL
The default SQL package provides support for connecting to common
database types (sqlite, mysql, etc) for auto completion and query
execution.  I don't use SQL currently but whenever I need it it's
there.
#+begin_src emacs-lisp
(use-package sql
  :straight nil
  :init
  (setq sql-display-sqli-buffer-function nil))
#+end_src
** WIP Ada
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Check out [[file:elisp/ada-mode.el][ada-mode]], my custom ~ada-mode~ that replaces the default
one.  This mode just colourises stuff, and uses eglot and a language
server to do the hard work.

#+begin_src emacs-lisp
(use-package ada-mode
  :straight nil
  :load-path "elisp/"
  :defer t
  :config
  (with-eval-after-load "eglot"
    (add-hook 'ada-mode-hook #'eglot)))
#+end_src
** NHexl
Hexl-mode is the inbuilt package within Emacs to edit hex and binary
format buffers.  There are a few problems with hexl-mode though,
including an annoying prompt on /revert-buffer/.

Thus, nhexl-mode!  It comes with a few other improvements. Check out
the [[https://elpa.gnu.org/packages/nhexl-mode.html][page]] yourself.
#+begin_src emacs-lisp
(use-package nhexl-mode
  :straight t
  :mode "\\.bin")
#+end_src
** C/C++
Setup for C and C++ modes via the cc-mode package.  C and C++ are
great languages for general purpose programming.  My preferred choice
when I want greater control over memory management.
*** cc-mode
Tons of stuff, namely:
+ ~auto-fill-mode~ for 80 char limit
+ Some keybindings to make evil statement movement is easy
+ Lots of pretty symbols
+ Indenting options and a nice (for me) code style for C (though
  aggressive indent screws with this a bit)
+ Auto inserts to get a C file going
#+begin_src emacs-lisp
(use-package cc-mode
  :defer t
  :hook
  (c-mode-hook   . auto-fill-mode)
  (c++-mode-hook . auto-fill-mode)
  :general
  (:keymaps '(c-mode-map c++-mode-map)
   :states '(normal motion visual)
   "(" #'c-beginning-of-statement
   ")" #'c-end-of-statement)
  :pretty
  (c-mode-hook
   ("puts"    . "φ")
   ("fputs"   . "ϕ")
   ("printf"  . "ω")
   ("fprintf" . "Ω")
   ("NULL"    . "Ø")
   ("true"    . "⊨")
   ("false"   . "⊭")
   ("!"       . "¬")
   ("&&"      . "⋀")
   ("||"      . "⋁")
   ("for"     . "∀")
   ("return"  . "⟼"))
  (c++-mode-hook
   ("nullptr" . "Ø")
   ("string"  . "𝕊")
   ("vector"  . "ℓ")
   ("puts"    . "φ")
   ("fputs"   . "ϕ")
   ("printf"  . "ω")
   ("fprintf" . "Ω")
   ("NULL"    . "Ø")
   ("true"    . "⊨")
   ("false"   . "⊭")
   ("!"       . "¬")
   ("&&"      . "⋀")
   ("||"      . "⋁")
   ("for"     . "∀")
   ("return"  . "⟼"))
  :init
  (setq-default c-basic-offset 2)
  (setq-default c-auto-newline nil)
  (setq-default c-default-style '((other . "user")))
  :auto-insert
  (("\\.c\\'" . "C skeleton")
   ""
   "/* " (file-name-nondirectory (buffer-file-name (current-buffer))) "\n"
   " * Created: " (format-time-string "%Y-%m-%d") "\n"
   " * Author: " user-full-name "\n"
   " * Description: " _ "\n"
   " */\n"
   "\n")
  (("\\.cpp\\'" "C++ skeleton")
   ""
   "/* " (file-name-nondirectory (buffer-file-name (current-buffer))) "\n"
   " * Created: " (format-time-string "%Y-%m-%d") "\n"
   " * Author: " user-full-name "\n"
   " * Description: " _ "\n"
   " */\n"
   "\n")
  :config
  (c-add-style
   "user"
   '((c-basic-offset . 2)
     (c-comment-only-line-offset . 0)
     (c-hanging-braces-alist (brace-list-open)
                             (brace-entry-open)
                             (substatement-open after)
                             (block-close . c-snug-do-while)
                             (arglist-cont-nonempty))
     (c-cleanup-list brace-else-brace)
     (c-offsets-alist
      (statement-block-intro . +)
      (substatement-open . 0)
      (access-label . -)
      (inline-open  . 0)
      (label . 0)
      (statement-cont . +)))))
#+end_src
*** Clang format
Clang format comes inbuilt with clang, so download that before using
this.  Formats C/C++ files depending on a format (checkout the Clang
format [[file:~/Dotfiles/ClangFormat/.clang-format][config file]] in my dotfiles).

#+begin_src emacs-lisp
(use-package clang-format
  :straight nil
  :load-path "/usr/share/clang/"
  :after cc-mode
  :commands (+code/clang-format-region-or-buffer
             clang-format-mode)
  :hook
  (c-mode-hook . clang-format-mode)
  (c++-mode-hook . clang-format-mode)
  :general
  (code-leader
    :keymaps '(c-mode-map c++-mode-map)
    "f" #'+code/clang-format-region-or-buffer)
  :config
  (define-minor-mode clang-format-mode
    "On save formats the current buffer via clang-format."
    :lighter nil
    (let ((save-func (proc (interactive)
                           (clang-format-buffer))))
      (if clang-format-mode
          (add-hook 'after-save-hook save-func nil t)
        (remove-hook 'after-save-hook save-func t))))
  (defun +code/clang-format-region-or-buffer ()
    (interactive)
    (if (mark)
        (clang-format-region (region-beginning) (region-end))
      (clang-format-buffer))))
#+end_src
*** cc org babel
To ensure org-babel executes language blocks of C/C++ I need to add it
as an option in ~org-babel-load-languages~.
#+begin_src emacs-lisp
(use-package org
  :after cc-mode
  :init
  (setf (alist-get 'C org-babel-load-languages) t))
#+end_src
** D
D is a systems level programming language with C-style syntax.  I
think it has some interesting ideas such as a toggleable garbage
collector.  Here I just install the D-mode package, enable ~org-babel~
execution of d-mode blocks and alias ~D-mode~ with ~d-mode~.

#+begin_src emacs-lisp
(use-package d-mode
  :straight t
  :config
  (fset 'D-mode 'd-mode)
  (with-eval-after-load "org-mode"
    (setf (alist-get 'd org-babel-load-languages) t)))
#+end_src
** Racket
A scheme with lots of stuff inside it.  Using it for a language design
book so it's useful to have some Emacs binds for it.
#+begin_src emacs-lisp
(use-package racket-mode
  :straight t
  :hook (racket-mode-hook . racket-xp-mode)
  :display
  ("\\*Racket.*"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :init
  (setq racket-documentation-search-location 'local)
  :general
  (nmap
    :keymaps 'racket-describe-mode-map
    "q" #'quit-window)
  (nmap
    :keymaps 'racket-mode-map
    "gr" #'racket-eval-last-sexp)
  (local-leader
    :keymaps '(racket-mode-map racket-repl-mode-map)
    "d" #'racket-repl-describe)
  (local-leader
    :keymaps 'racket-mode-map
    "r" #'racket-run
    "i" #'racket-repl
    "e" #'racket-send-definition
    "sr" #'racket-send-region
    "sd" #'racket-send-definition))
#+end_src
** WIP CSharp
:PROPERTIES:
:header-args:emacs-lisp: :tangle no
:END:
Haven't used C# in a while, but Emacs is alright for it with
omnisharp.
#+begin_src emacs-lisp
(use-package csharp-mode
  :defer t
  :pretty
  (csharp-mode-hook
   ("null"      . "∅")
   ("string"    . "𝕊")
   ("List"      . "ℓ")
   ("WriteLine" . "φ")
   ("Write"     . "ω")
   ("true"      . "⊨")
   ("false"     . "⊭")
   ("!"         . "¬")
   ("&&"        . "⋀")
   ("||"        . "⋁")
   ("for"       . "∀")
   ("return"    . "⟼")))
#+end_src
** Java
I kinda dislike Java, but if necessary I will code in it.  Just setup
a style and some pretty symbols.  You can use LSP to get cooler
features to be fair.
#+begin_src emacs-lisp
(use-package ob-java
  :straight nil
  :defer t
  :pretty
  (java-mode-hook
   ("println" . "φ")
   ("printf"  . "ω")
   ("null"    . "Ø")
   ("true"    . "⊨")
   ("false"   . "⊭")
   ("!"       . "¬")
   ("&&"      . "⋀")
   ("||"      . "⋁")
   ("for"     . "∀")
   ("return"  . "⟼"))
  :config
  (with-eval-after-load "cc-mode"
    (c-add-style
     "java"
     '((c-basic-offset . 4)
       (c-comment-only-line-offset 0 . 0)
       (c-offsets-alist
        (inline-open . 0)
        (topmost-intro-cont . +)
        (statement-block-intro . +)
        (knr-argdecl-intro . 5)
        (substatement-open . 0)
        (substatement-label . +)
        (label . +)
        (statement-case-open . +)
        (statement-cont . +)
        (arglist-intro . c-lineup-arglist-intro-after-paren)
        (arglist-close . c-lineup-arglist)
        (brace-list-intro first c-lineup-2nd-brace-entry-in-arglist c-lineup-class-decl-init-+ +)
        (access-label . 0)
        (inher-cont . c-lineup-java-inher)
        (func-decl-cont . c-lineup-java-throws))))
    (add-to-list 'c-default-style '(java-mode . "java")))

  (with-eval-after-load "abbrev"
    (define-abbrev-table 'java-mode-abbrev-table nil)
    (add-hook 'java-mode-hook
              (proc (setq-local local-abbrev-table java-mode-abbrev-table)))))
#+end_src
** Haskell
Haskell is a static lazy functional programming language (what a
mouthful).  It's quite a beautiful language and really learning it will
change the way you think about programming.  However, my preferred
functional language is still unfortunately Lisp so no extra brownie
points there.

Here I configure the REPL for Haskell via the
~haskell-interactive-mode~.  I also load my custom package
[[file:elisp/haskell-multiedit.el][haskell-multiedit]] which allows a user to create temporary
~haskell-mode~ buffers that, upon completion, will run in the REPL.
Even easier than making your own buffer.
#+begin_src emacs-lisp
(use-package haskell-mode
  :hook
  (haskell-mode-hook . haskell-indentation-mode)
  (haskell-mode-hook . interactive-haskell-mode)
  :custom
  (haskell-interactive-prompt "[λ] ")
  (haskell-interactive-prompt-cont "{λ} ")
  (haskell-interactive-popup-errors nil)
  (haskell-stylish-on-save nil)
  (haskell-process-type 'stack-ghci)
  :general
  (shell-leader
    "h" #'+shell/toggle-haskell-repl)
  :display
  ("\\*haskell.**\\*"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :config
  (load (concat user-emacs-directory "elisp/haskell-multiedit.el"))
  (+oreo/create-toggle-function
   +shell/toggle-haskell-repl
   "*haskell*"
   haskell-interactive-bring
   nil))
#+end_src
** Python
Works well for python.  If you have ~pyls~ it should be on your path, so
just run eglot if you need.  But an LSP server is not necessary for a
lot of my time in python.  Here I also setup org-babel for python
source code blocks.
#+begin_src emacs-lisp
(use-package python
  :defer t
  :straight nil
  :pretty
  (python-mode-hook
   ("None"   . "Ø")
   ("list"   . "ℓ")
   ("List"   . "ℓ")
   ("str"    . "𝕊")
   ("True"   . "⊨")
   ("False"  . "⊭")
   ("!"      . "¬")
   ("&&"     . "⋀")
   ("||"     . "⋁")
   ("for"    . "∀")
   ("print"  . "φ")
   ("lambda" . "λ")
   ("return" . "⟼")
   ("yield"  . "⟻"))
  :init
  (setq python-indent-offset 4)
  :config
  (with-eval-after-load "org-mode"
    (setf (alist-get 'python org-babel-load-languages) t)))
#+end_src
*** Python shell
Setup for python shell, including a toggle option
#+begin_src emacs-lisp
(use-package python
  :straight nil
  :commands +python/toggle-repl
  :general
  (shell-leader
    "p" #'+shell/python-toggle-repl)
  :display
  ("\\*Python\\*"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :config
  (+oreo/create-toggle-function
   +shell/python-toggle-repl
   "*Python*"
   run-python
   nil))
#+end_src
** YAML
YAML is a data language which is useful for config files.
#+begin_src emacs-lisp
(use-package yaml-mode
  :straight t)
#+end_src
** HTML/CSS/JS
Firstly, web mode for consistent colouring of syntax.
#+begin_src emacs-lisp
(use-package web-mode
  :mode ("\\.html" . web-mode)
  :mode ("\\.js"   . web-mode)
  :mode ("\\.css"  . web-mode)
  :custom
  ((web-mode-code-indent-offset 2)
   (web-mode-markup-indent-offset 2)
   (web-mode-css-indent-offset 2)))
#+end_src
*** Emmet
Emmet for super speed code writing.
#+begin_src emacs-lisp
(use-package emmet-mode
  :hook (web-mode-hook . emmet-mode)
  :general
  (imap
    :keymaps 'emmet-mode-keymap
    "TAB" #'emmet-expand-line
    "M-j" #'emmet-next-edit-point
    "M-k" #'emmet-prev-edit-point))
#+end_src
*** HTML Auto insert
#+begin_src emacs-lisp
(use-package web-mode
  :auto-insert
  (("\\.html\\'" . "HTML Skeleton")
   ""
   "<!doctype html>
<html class='no-js' lang=''>
  <head>
    <meta charset='utf-8'>
    <meta http-equiv='x-ua-compatible' content='ie=edge'>
    <title>"(read-string "Enter title: ") | """</title>
    <meta name='description' content='" (read-string "Enter description: ") | "" "'>
    <meta name='author' content='"user-full-name"'/>
    <meta name='viewport' content='width=device-width, initial-scale=1'>

    <link rel='apple-touch-icon' href='/apple-touch-icon.png'>
    <link rel='shortcut icon' href='/favicon.ico'/>
    <!-- Place favicon.ico in the root directory -->

  </head>
  <body>
    <!--[if lt IE 8]>
      <p class='browserupgrade'>
      You are using an <strong>outdated</strong> browser. Please
      <a href='http://browsehappy.com/'>upgrade your browser</a> to improve
      your experience.
      </p>
    <![endif]-->
"
   _
   "     </body>
</html>"))
#+end_src
** Typescript
Kinda expressive, interesting.
#+begin_src emacs-lisp
(use-package typescript-mode
  :defer t
  :init
  (setq typescript-indent-level 2))
#+end_src
** Common Lisp
Common Lisp is a dialect of Lisp, the most /common/ one around.  Emacs
comes with builtin Lisp support of course, but a REPL would be nice.

Enter /SLY/.  Sly is a fork of /SLIME/ and is *mandatory* for lisp
development on Emacs.

#+begin_src emacs-lisp
(use-package sly
  :straight t
  :init
  (setq inferior-lisp-program "sbcl")
  :display
  ("\\*sly-db"
   (display-buffer-at-bottom)
   (window-height . 0.5))
  ("\\*sly-"
   (display-buffer-at-bottom)
   (window-height . 0.25))
  :config
  (evil-set-initial-state 'sly-db-mode 'emacs)
  (with-eval-after-load "org"
    (setq-default org-babel-lisp-eval-fn #'sly-eval))
  (with-eval-after-load "company"
    (add-hook 'sly-mrepl-hook #'company-mode))
  (+oreo/create-toggle-function
   +shell/toggle-sly
   "*sly-mrepl for sbcl*"
   sly-mrepl
   nil)
  :general
  (shell-leader
    "s" #'+shell/toggle-sly)
  (nmap
    :keymaps '(lisp-mode-map sly-mrepl-mode-map)
    "gr" #'sly-eval-buffer
    "gd" #'sly-edit-definition
    "gR" #'sly-who-calls)
  (local-leader
    :keymaps '(lisp-mode-map sly-mrepl-mode-map)
    "s" #'+shell/toggle-sly
    "c" #'sly-compile-file
    "a" #'sly-apropos
    "d" #'sly-describe-symbol
    "D" #'sly-mrepl-sync
    "E" #'sly-eval-defun)
  (local-leader
    :keymaps 'lisp-mode-map
    :infix "e"
    "b" #'sly-eval-buffer
    "e" #'sly-eval-last-expression
    "f" #'sly-eval-defun
    "r" #'sly-eval-region)
  (nmap
    :keymaps 'sly-inspector-mode-map
    "q" #'sly-inspector-quit))
#+end_src
*** Lisp indent function
Add a new lisp indent function which indents newline lists more
appropriately.
#+begin_src emacs-lisp
(use-package lisp-mode
  :straight nil
  :pretty
  (lisp-mode-hook
   ("lambda"  . "λ")
   ("t"       . "⊨")
   ("nil"     . "Ø")
   ("and"     . "⋀")
   ("or"      . "⋁")
   ("defun"   . "ƒ")
   ("for"     . "∀")
   ("mapc"    . "∀")
   ("mapcar"  . "∀"))
  :general
  (:states '(normal motion visual)
   :keymaps '(emacs-lisp-mode-map lisp-mode-map)
   ")" #'sp-next-sexp
   "(" #'sp-previous-sexp)
  :config
  (defun +oreo/lisp-indent-function (indent-point state)
    (let ((normal-indent (current-column))
          (orig-point (point)))
      (goto-char (1+ (elt state 1)))
      (parse-partial-sexp (point) calculate-lisp-indent-last-sexp 0 t)
      (cond
       ;; car of form doesn't seem to be a symbol, or is a keyword
       ((and (elt state 2)
             (or (not (looking-at "\\sw\\|\\s_"))
                 (looking-at ":")))
        (if (not (> (save-excursion (forward-line 1) (point))
                    calculate-lisp-indent-last-sexp))
            (progn (goto-char calculate-lisp-indent-last-sexp)
                   (beginning-of-line)
                   (parse-partial-sexp (point)
                                       calculate-lisp-indent-last-sexp 0 t)))
        ;; Indent under the list or under the first sexp on the same
        ;; line as calculate-lisp-indent-last-sexp.  Note that first
        ;; thing on that line has to be complete sexp since we are
        ;; inside the innermost containing sexp.
        (backward-prefix-chars)
        (current-column))
       ((and (save-excursion
               (goto-char indent-point)
               (skip-syntax-forward " ")
               (not (looking-at ":")))
             (save-excursion
               (goto-char orig-point)
               (looking-at ":")))
        (save-excursion
          (goto-char (+ 2 (elt state 1)))
          (current-column)))
       (t
        (let ((function (buffer-substring (point)
                                          (progn (forward-sexp 1) (point))))
              method)
          (setq method (or (function-get (intern-soft function)
                                         'lisp-indent-function)
                           (get (intern-soft function) 'lisp-indent-hook)))
          (cond ((or (eq method 'defun)
                     (and (null method)
                          (> (length function) 3)
                          (string-match "\\`def" function)))
                 (lisp-indent-defform state indent-point))
                ((integerp method)
                 (lisp-indent-specform method state
                                       indent-point normal-indent))
                (method
                 (funcall method indent-point state))))))))
  (setq-default lisp-indent-function #'+oreo/lisp-indent-function))
#+end_src
*** Emacs lisp
#+begin_src emacs-lisp
(use-package elisp-mode
  :straight nil
  :general
  (vmap
    :keymaps '(emacs-lisp-mode-map lisp-interaction-mode-map)
    "gr" #'eval-region))
#+end_src