legacy-dotfiles/emacs/.emacs.d/init.org

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* Introduction

  Inspired by [[Other such projects][other such projects]], here is my Emacs initialization
  file.

  *Note:* This is not my entire Emacs initialization file. It's a
  work-in-progress.

** Setup

   I could use org-babel to load this file, but I don't like my
   initialization file having too many dependencies, especially big
   dependencies, and org is big. It may be strange for you to read
   this, as I have placed my entire Emacs configuration in an org-mode
   file, but here are the make targets I use to tangle and
   subsequently byte-compile my init file:

   #+BEGIN_SRC makefile :tangle no
     %.elc: %.el
         emacs -Q -batch -eval "(byte-compile-file \"$<\")"

     init.el: init.org
         emacs -Q -batch -l "ob-tangle" -eval "(org-babel-tangle-file \"init.org\")
   #+END_SRC

   Executing the second target (either through make, or manually) will
   get you my Emacs initialization file in plain Emacs Lisp.

   *Note:* If you look at this file in its source form you will notice
   that I actually tangle ~init.org~ into ~init2.el~. This is a temporary
   measure so that I can gradually move my configuration from my
   existing ~init.el~ file into ~init.org~ without much trouble. Once I
   have emptied out my ~init.el~ I will instruct babel to tangle into
   ~init.el~, this code already reflects that.

** The ~oni:~ prefix

   To keep my functions and variables from ever accidentally
   interfering with other packages or Emacs internal variables I
   prefix all the functions I write and variables I declare with ~oni:~.
   You don't have to copy it if you copy anything from this file, as
   long as you do it consistently.

   I sometimes forget to do this, though.

** The ~depends-on~ snippets

   At certain points in this document you will find bits of code that
   look like:

   #+BEGIN_SRC emacs-lisp :tangle no
     (depends-on "somepackage")
   #+END_SRC

   These calls are from the Cask DSL. They specify that my
   configuration depends on some package found in one of the ELPA
   repositories I have setup.

   These snippets don't belong in your =init.el=, but instead in a
   separate =Cask= file, and only if you use Cask, not if you just use
   the standard ~package.el~.

** Other such projects

   As stated, this project is inspired and influenced by other
   literate configurations. Here is a list of some of the ones I've
   found:

   - [[http://sachac.github.io/.emacs.d/Sacha.html][Sacha Chua]]
   - [[http://www.wisdomandwonder.com/wordpress/wp-content/uploads/2014/03/C3F.html][Grant Rettke]]
   - [[https://github.com/wasamasa/dotemacs][Vasilij Schneidermann]]

* Preparation

  Some things have to be done to make sure that everything works as it
  should. This includes enabling lexical binding, loading Cask and
  keeping some comments.

** Use lexical binding

   For some of my functions, and general coolness, lexical binding is
   a must. Without it, closures don't work for example. This line
   needs to appear at the beginning of the file to work.

   #+BEGIN_SRC emacs-lisp :padline no
     ;; -*- lexical-binding: t -*-
   #+END_SRC

** Keep package.el from changing my init

   Some time ago my init file was changed by Emacs. It added a single
   line of code and some explanatory comments. Apparently I need to
   keep this comment in my initialization file so that Emacs doesn't
   try to add the code again. I actually use [[http://cask.readthedocs.org/en/latest/][Cask]] to manage and load
   my packages so I don't need this.

   #+BEGIN_SRC emacs-lisp
     ;; (package-initialize)
   #+END_SRC

** Load Cask

   I use Cask to manage my installed packages and for that to work I
   need to load Cask at the start of the initialization file. This
   should be executed both when byte-compiling and loading at run-time
   so that other bits and pieces can byte-compile without warnings or
   errors.

   #+BEGIN_SRC emacs-lisp
     (eval-and-compile
       (require 'cask "~/projects/ext/cask/cask.el")
       (cask-initialize))
   #+END_SRC

** Some helper functions

   Certain functions make life a lot easier when configuring Emacs.
   These don't generally belong to any one specific customization, but
   make things look a lot prettier.

*** Optimized ~with-eval-after-load~

    First offered [[http://www.lunaryorn.com/2013/05/01/byte-compiling-eval-after-load.html][here]] and then later updated [[http://www.lunaryorn.com/2013/06/25/introducing-with-eval-after-load.html][here]] (when
    ~with-eval-after-load~ was added). Makes for very nice on-demand
    settings loading.

    #+BEGIN_SRC emacs-lisp
      ;; http://www.lunaryorn.com/2013/06/25/introducing-with-eval-after-load/
      (defmacro stante-after (feature &rest forms)
        "After FEATURE is loaded, evaluate FORMS.

      FEATURE may be an unquoted feature symbol or a file name, see
      `eval-after-load'."
        (declare (indent 1) (debug t))
        `(,(if (or (not byte-compile-current-file)
                   (if (symbolp feature)
                       (require feature nil :noerror)
                     (load feature :no-message :no-error)))
               `progn
             (message "stante-after: cannot find %s" feature)
             'with-no-warnings)
          (with-eval-after-load ',feature ,@forms)))
    #+END_SRC

*** Turn off minor modes

    This macro creates a function that will turn off a minor mode that
    passed to it.

    #+BEGIN_SRC emacs-lisp
      (defmacro turn-off (func)
        "Create a function that will turn off FUNC when called."
        `(lambda () (eval (,func -1))))
    #+END_SRC

*** Change settings

    Sometimes a mode just needs to change a certain setting to a
    specific value.

    #+BEGIN_SRC emacs-lisp
      (defmacro change-settings (&rest settings)
        "Create a function that changes the value of NAME to VALUE."
        `(lambda () (setq ,@settings)))
    #+END_SRC

*** Eval after init

    Some things can only really work after all other initialization
    functions have completed. For example, any functions that require
    any ELPA packages to be loaded, unless you want to load it in your
    init manually (and have it loaded again later on after your config
    has run).

    #+BEGIN_SRC emacs-lisp
      (defmacro oni:eval-after-init (&rest body)
        "Defer execution of BODY until after Emacs init."
        (declare (indent 0))
        `(add-hook 'emacs-startup-hook #'(lambda () ,@body)))
    #+END_SRC

*** Whitespace only with tabs

    In some modes I want to see the tabs in a buffer. Though I don't
    want to be overwhelmed by seeing all spaces and line endings.

    #+BEGIN_SRC emacs-lisp
      (defvar whitespace-style)

      (defun oni:whitespace-only-tabs ()
        (setq-local whitespace-style '(face tabs))
        (whitespace-mode))
    #+END_SRC

** Useful functions

   During your editing in Emacs you will undoubtedly find the need to
   define your own editing functions or macros. Here are mine.

*** Delete the contents of the string at point

    First we define the function. It was inspired by [[http://www.masteringemacs.org/][Mickey's post on
    swapping quote symbols]], mostly copied even. First we check if we
    are even in a string, and if not we throw an error, after that we
    move back to the beginning of the string, store that point, go to
    the end of the string (using =forward-sexp=) and then delete the
    region between the two points (non-inclusive).

    #+BEGIN_SRC emacs-lisp
      (defun oni:delete-string-contents ()
        (interactive)

        (unless (nth 3 (syntax-ppss))
          (error "You must be in a string for this command to work"))

        (save-excursion
          (while (nth 3 (syntax-ppss)) (forward-char -1))

          (let ((bos (point)))
            (forward-sexp)
            (delete-region (1+ bos) (1- (point))))))
    #+END_SRC

    Since for interactive functions it's kind of a pain to have to use
    a personal "namespace" I prefer naming them regularly as if they're
    just part of the environment. If ever Emacs comes up with a similar
    function with the same name, I'd prefer using the built-in version.

    #+BEGIN_SRC emacs-lisp
      (unless (fboundp 'delete-string-contents)
        (defalias 'delete-string-contents 'oni:delete-string-contents))
    #+END_SRC

    Lastly, any function worth using often should probably be easily
    accessible with a keybinding. In my case the {{{key(C-c i s)}}} is
    inspired by the Vim keybindings like {{{key(ci")}}}.

    #+BEGIN_SRC emacs-lisp
      (global-set-key (kbd "C-c i s") 'delete-string-contents)
    #+END_SRC

* General customization

  These customizations don't belong with any specific mode.

** Set some personal information

   This information is used by some emacs commands and modules to make
   your life easier.

   #+BEGIN_SRC emacs-lisp
     (setq user-full-name "Tom Willemse"
           user-mail-address "tom@ryuslash.org")
   #+END_SRC

** Turn-off menu bar

   The menu bar is one of the UI elements which work best with mouses.
   Sure you can change your toolkit's key bindings to allow you to
   more easily navigate, but {{{key(M-x)}}} or {{{key(M-`)}}}[fn:1]
   are easier if you don't use the mouse. Long story short: It has got
   to go.

   #+BEGIN_SRC emacs-lisp
     (menu-bar-mode -1)
   #+END_SRC

   I also do this in my =.Xdefaults= file, as that is applied sooner:

   #+BEGIN_SRC conf-xdefaults :tangle no
     Emacs.menuBar: off
   #+END_SRC

** Turn-off tool bar

   The toolbar is another such thing, and it takes up quite a bit more
   space too. Icons can look pretty cool, but in the end if you're not
   going to click them they don't really server much of a purpose.
   Again: It has got to go.

   #+BEGIN_SRC emacs-lisp
     (tool-bar-mode -1)
   #+END_SRC

   I also do this in my =.Xdefaults= as those settings are applied
   sooner.

   #+BEGIN_SRC conf-xdefaults :tangle no
     Emacs.toolBar: off
   #+END_SRC

** Turn-off blinking cursor

   I suppose a blinking cursor doesn't get lost very easily. But on
   the other hand, it can induce quite a few more headaches.

   I've noticed that I don't really lose my cursor position all that
   much, really, so there doesn't seem to be any point in making it
   blink. Here we go again: It has got to go.

   #+BEGIN_SRC emacs-lisp
     (blink-cursor-mode -1)
   #+END_SRC

   I also do this in my =.Xdefaults=, as those settings are applied
   sooner.

   #+BEGIN_SRC conf-xdefaults :tangle no
     Emacs.cursorBlink: off
   #+END_SRC

** Turn-off line numbers

   As I'm currently using svg-mode-line-themes[fn:2] for my ~mode-line~
   I don't need to show these. Also I didn't really use them much, I
   don't often need to know what line I'm on.

   #+BEGIN_SRC emacs-lisp
     (line-number-mode -1)
   #+END_SRC

** Turn-off tooltips

   Tooltips are another one of those UI elements that aren't quite
   keyboard-friendly. As usually this information is shown just as well
   in the echo area, this is not necessary.

   #+BEGIN_SRC emacs-lisp
     (tooltip-mode -1)
   #+END_SRC

** Change cursor type

   I prefer using a bar as a cursor, as opposed to a box. Using a bar
   is a better way of representing the location of the cursor, in my
   opinion.

   #+BEGIN_SRC emacs-lisp
     (setq-default cursor-type 'bar)
   #+END_SRC

   I use a bar cursor that's already pretty thin, so having an even
   thinner one in inactive windows is not very clear. Even when I was
   using a box cursor I didn't like seeing a hollow box everywhere my
   focus /wasn't/.

   #+BEGIN_SRC emacs-lisp
     (setq-default cursor-in-non-selected-windows nil)
   #+END_SRC

** Truncate long lines

   Sometimes, very long lines can't help but show up in code. The
   default of wrapping lines around to the next line and showing an
   image in the fringe is very visually disturbing to me when looking
   at code[fn:3]. So I prefer to have it just run off the screen.

   #+BEGIN_SRC emacs-lisp
     (setq-default truncate-lines t)
   #+END_SRC

** Change default frame settings

   Usually, most of these settings would be done with functions like
   =set-frame-font= or =scroll-bar-mode=, but working with the Emacs
   Daemon sometimes creates extra complications, because you might
   start a graphical environment at some point (I usually do
   immediately), but the startup process isn't.

*** Use a fantastic font

    I've tried several fonts, and all of them were nice, but came up
    short on some way. Some didn't have italic variants, some had
    dotted zeroes instead of dashed zeroes, some even had entirely
    clear zeroes which make them look like ~O~'s, others had
    boring-looking parentheses[fn:4]. Not Fantasque Sans
    Mono[fn:5][fn:6], it is awesome. If your web browser supports web
    fonts you should also see it used in the code blocks here.

    For normal Emacs setups you might use the =set-frame-font= function
    like so:

    #+BEGIN_SRC emacs-lisp :tangle no
      (set-frame-font "Fantasque Sans Mono-15" nil t)
    #+END_SRC

    However, this doesn't work when running Emacs as a Daemon. You
    could (especially with lexical binding) add an
    =after-make-frame-functions= hook or something similar, but I find
    it easier to just specify the font in the =default-frame-alist=.

    #+NAME: default-frame-font
    #+BEGIN_SRC emacs-lisp :tangle no
      (font . "Fantasque Sans Mono-15")
    #+END_SRC

    I also do this in my =.Xdefaults= as those settings are applied
    sooner.

    #+BEGIN_SRC conf-xdefaults :tangle no
      Emacs.font: Fantasque Sans Mono-15
    #+END_SRC

*** Hide the scroll bar

    The scroll-bar is almost just as informative as the current line
    number and buffer position information shown in the (my) mode
    line. As I don't usually need to know where I am, other than the
    current line number occasionally, and I don't use the mouse, the
    scroll bar doesn't add anything and only takes up space. Once
    more: It has got to go.

    Normally you would use something along the lines of:

    #+BEGIN_SRC emacs-lisp :tangle no
      (scroll-bar-mode -1)
    #+END_SRC

    However, this doesn't work when running Emacs as a Daemon. So
    instead I specify it in the =default-frame-alist=.

    #+NAME: default-frame-scroll-bar
    #+BEGIN_SRC emacs-lisp :tangle no
      (vertical-scroll-bars . nil)
    #+END_SRC

*** Bringing it all together

    So I've explained the reasons for each individual setting, but to
    get them to work they have to be put in the =default-frame-alist=.
    Here is the final setting:

    #+BEGIN_SRC emacs-lisp :noweb yes
      (setq default-frame-alist
            `(<<default-frame-font>>
              <<default-frame-scroll-bar>>))
    #+END_SRC

** Set the frame title

   Show the buffer name in the frame title to make multiple frames
   identifiable by the buffer they're showing.

   #+BEGIN_SRC emacs-lisp
     (setq frame-title-format '(:eval (concat "GNU Emacs: " (buffer-name))))
   #+END_SRC

** Don't show dialog boxes

   Unfortunately this doesn't remove /all/ dialog boxes, but at least it
   keeps some of them from popping up. According to the docstring it
   should only change anything for when the mouse is used, which I
   don't ever do, but I still feel safer keeping this in my
   configuration.

   #+BEGIN_SRC emacs-lisp
     (setq use-dialog-box nil)
   #+END_SRC

** Split windows equally

   When splitting windows, give them all an equal amount of space. For
   those very few time that I have more than two windows in my Emacs
   frame it is much nicer to have each of them get ~33% space instead
   of 50%, 25% and 25%. The way I have my desktop set-up I don't ever
   split my windows horizontally.

   #+BEGIN_SRC emacs-lisp
     (setq window-combination-resize t)
   #+END_SRC

** Keep the cursor steady when scrolling

   When scrolling through the buffer with, for example, {{{key(C-v)}}}
   or {{{key(M-v)}}}, I find it much more intuitive to have the cursor
   stay in the relative screen position from before. Otherwise I get
   confused every time.

   #+BEGIN_SRC emacs-lisp
     (setq scroll-preserve-screen-position t)
   #+END_SRC

** Don't show a mode line for completions

   One of the things I dislike about Emacs is its rigidity concerning
   windows and other UI elements. One very simple way to make it
   /feel/ less so is to show less of it where possible. A mode line for
   completion buffers creates more separation than necessary, and I
   can't recall a single time where I've used the completion's mode
   line for anything.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'completion-list-mode-hook
               (lambda () (setq mode-line-format nil)))
   #+END_SRC

** Use pixels, not columns/rows to resize frames.

   As of Emacs 24.4 frames can resize to pixel sizes instead of
   columns and rows. This keeps annoying gaps from forming when using
   a tiling window manager. The real difference is that when this is
   done now, the actual text portions of the window get the extra
   space, not some fringe or margin. This looks much nicer.

   #+BEGIN_SRC emacs-lisp
     (setq frame-resize-pixelwise t)
   #+END_SRC

** Don't just quit Emacs with {{{key(C-x C-c)}}} in the daemon

   When working with Emacs as a daemon, which I do almost all of the
   time, I prefer using {{{key(C-x C-c)}}} to close the current frame
   instead of the entire session. Before this change I would
   occasionally close my session by mistake.

   #+BEGIN_SRC emacs-lisp
     (defun oni:close-client-window ()
       "Close a client's frames."
       (interactive)
       (server-save-buffers-kill-terminal nil))

     (when (daemonp)
       (global-set-key (kbd "C-x C-c") 'oni:close-client-window))
   #+END_SRC

** Don't minimize the frame with {{{key(C-z)}}}

   One of the more annoying things that can happen is accidentally
   minimizing the frame you're working with. This doesn't really matter
   if you're working on a normal stacking window manager, but with a
   tiling window manager and no task bar this just causes the Emacs
   frame to hang until it is refocused or disappear with no way to get
   it back.

   #+BEGIN_SRC emacs-lisp
     (when (or window-system (daemonp))
       (global-unset-key (kbd "C-z")))
   #+END_SRC

** Lazily load some buffers

   Don't load all buffers right away. Having a lot of buffers and
   switching between projects a lot can take up quite a bit of time.

   *Note:* See my [[Vacuous defvar][note]] on vacuous defvar for this use of =defvar=.

   #+BEGIN_SRC emacs-lisp
     (defvar desktop-restore-eager)
     (setq desktop-restore-eager 5)
   #+END_SRC

** Ask for a ~y~ or ~n~, not ~yes~ or ~no~.

   Emacs starts out asking for you to type ~yes~ or ~no~ with most
   important questions. It is possible that this is used for such
   important questions where accidentally saying ~yes~ when you meant ~no~
   would be catastrophic (or at least could be). However, I've never
   (so far) had this problem, and I find it quite tedious to have to
   write out ~yes~ or ~no~ and then press {{{key(RET)}}}, give me a simple
   ~y~ or ~n~ with no {{{key(RET)}}} required and I'm quite happy.

   #+BEGIN_SRC emacs-lisp
     (defalias 'yes-or-no-p 'y-or-n-p)
   #+END_SRC

** Use =hippie-expand=, not =dabbrev-expand=

   I've never actually used =dabbrev-expand=, and only rarely use
   =hippie-expand= really, but since =hippie-expand= also includes a
   =dabbrev= expander and a lot more than just that, it seems alright to
   do this.

   #+BEGIN_SRC emacs-lisp
     (defalias 'dabbrev-expand 'hippie-expand)
   #+END_SRC

** Setting up =load-path=

   First, to help, I create a function that takes a path, adds it to
   =load-path= and then checks to see if there is a file named
   ~loaddefs.el~ in the given path. If there is, it loads it. This
   ~loaddefs.el~ file is something that is created from autoload cookies
   in the files in some of these paths.

   Since the =load-path= is also important during byte-compilation, this
   function should be defined both at run-time and compile-time.

   #+BEGIN_SRC emacs-lisp
     (eval-and-compile
       (defun oni:loadpath-add-and-autoload (path)
         "Add PATH to `load-path' and load a `loaddefs.el' if it exists."
         (add-to-list 'load-path path)
         (let ((loaddefs (concat path "/loaddefs.el")))
           (when (file-exists-p loaddefs)
             (load loaddefs)))))
   #+END_SRC

   After that I add some directories to my =load-path= so I can use these
   libraries when wanted. One of these is the ~site-lisp~ directory in my
   ~.emacs.d~ directory, which is where I keep most of my personal
   non-ELPA modules (like module-specific initialization files). There
   are also some directories I include in ~vendor-lisp~, which is where I
   keep modules that I didn't write myself and, for some reason, can't
   or don't want to use ELPA for. Again it is important to realize that
   this information is relevant both at run-time and compile-time, so
   we wrap it with an =eval-and-compile=.

   #+BEGIN_SRC emacs-lisp
     (eval-and-compile
       (mapc #'oni:loadpath-add-and-autoload
             '("~/.emacs.d/site-lisp"
               "~/.emacs.d/vendor-lisp/mozrepl"
               "~/.emacs.d/vendor-lisp/eap" "/usr/share/emacs/site-lisp"
               "/usr/lib/node_modules/tern/emacs/")))
   #+END_SRC

** Turn off bidirectional text

   To speed things up a little, and because I have no contacts at all
   (so far) who use right-to-left text, there is no reason for me to
   use bidirectional text. For this reason I tell Emacs to always use
   left-to-right by default, instead of checking each paragraph.

   #+BEGIN_SRC emacs-lisp
     (setq-default bidi-paragraph-direction 'left-to-right)
   #+END_SRC

** Don't use tabs

   There is a war going on out there. Actually there are several, but
   the one I'm talking about here is the one about tabs vs. spaces. I
   have been deeply entrenched in the spaces camp for quite a while.
   Indentation always gets screwy for me if I don't use the exact same
   =tab-width= everyone else uses. I just like the consistency of using
   spaces.

   #+BEGIN_SRC emacs-lisp
     (setq-default indent-tabs-mode nil)
   #+END_SRC

** Use four spaces for indentation

   I once, long ago, started out with using eight spaces for each
   level of indentation. Although I think, technically, I was using
   tabs. This means that even just 3 levels of indentation take up a
   /huge/ amount of space that can't be used for anything else. Since I
   also try to limit the length of the lines in my code, this can make
   for very little code per line.

   I also tried (and enjoyed) two spaces, but after a while, looking
   at bigger files, I noticed that it all becomes a blur. Two spaces
   is not a big-enough visual difference to make code read nicely, in
   my opinion.

   So far, I have quite enjoyed four spaces for most code[fn:8].

   #+BEGIN_SRC emacs-lisp
     (setq-default tab-width 4)
   #+END_SRC

** Keep the message buffer from growing too large

   Keep at most one-thousand messages in the ~*Messages*~ buffer. I can
   leave my Emacs session running for quite long times, sometimes
   days, at a time. If there are a lot of messages it can get a little
   tricky to manage/search.

   #+BEGIN_SRC emacs-lisp
     (setq message-log-max 1000)
   #+END_SRC

** Reject SSL/TLS certificates that don't check out

   You just can't trust the internet. And I'd prefer to know if
   something goes wrong.

   #+BEGIN_SRC emacs-lisp
     (defvar gnutls-verify-error)

     (setq gnutls-verify-error t)
   #+END_SRC

** Use Conkeror to browse URLs

   Use the generic browse-url function to open URLs in Conkeror.

   #+BEGIN_SRC emacs-lisp
     (stante-after browse-url
       (setq browse-url-browser-function 'browse-url-generic)
       (setq browse-url-generic-program "conkeror"))
   #+END_SRC

* Major mode customization

  Many major modes offer and require some customization. I use the
  term major mode somewhat loosely here because some of these
  customizations don't actually deal with major modes, but full-on
  applications or frameworks like Gnus and Elnode.

** Org mode

   Org mode offers /a lot/ of customization options. Most of mine are in
   a separate file.

   Store org id locations in my Emacs data directory.

   #+BEGIN_SRC emacs-lisp
     (use-package org-id
       :defer t
       :config
       (setq org-id-locations-file
             (concat user-emacs-directory "data/org-id-locations")))
   #+END_SRC

*** Add org-mode appointments to the diary

    Diary offers reminders, which can be useful when scheduling
    appointments.

    #+BEGIN_SRC emacs-lisp
      (defadvice org-agenda-redo (after ext:org-agenda-redo-add-appts)
        "Pressing `r' on the agenda will also add appointments."
        (setq appt-time-msg-list nil)
        (org-agenda-to-appt))
    #+END_SRC

** Ansi term

   I don't use ansi term much. Though I probably should do it more.
   Eshell is much nicer for many reasons but it can't handle
   everything.

*** Close ansi-term buffer after exit

    After the ansi-term process ends it leaves a buffer. I don't use
    ansi term in such a way that this has ever been useful, so just kill
    the ansi-term buffer after the process quits, no matter the exit
    status. Usually this comes about when I press {{{key(C-d)}}} at the
    command prompt.

    #+BEGIN_SRC emacs-lisp
      (defadvice term-handle-exit (after oni:kill-buffer-after-exit activate)
        "Kill the term buffer if the process finished."
        (kill-buffer (current-buffer)))
    #+END_SRC

*** Fix some term keybindings

    =ansi-term= passes along a lot of characters correctly, but things
    like =forward-delete-word= are not, by default. This is confusing when
    you see one thing and another is sent. Passing the correct keys
    directly to the terminal fixes this problem.

    *Note:* See my [[Vacuous defvar][note]] on vacuous defvar for this use of =defvar=.

    *Note:* See my [[Function declarations][note]] on function declarations about the use of
    =declare-function=.

    #+BEGIN_SRC emacs-lisp
      (defvar term-raw-map)
      (declare-function term-send-raw-string "term")

      (defun oni:set-term-keys ()
        (cl-flet ((zcommand (key)
                    (lambda ()
                      (interactive) (term-send-raw-string key))))
          (define-key term-raw-map
            (kbd "C-<backspace>") (zcommand "\C-H"))))

      (add-hook 'term-mode-hook #'oni:set-term-keys)
    #+END_SRC

** Gnus

   Gnus is a very powerful news reader that also handles Email quite
   well. I've been using it for a while now, though not to its full
   extent I'm sure. This section contains customization for multiple
   major modes that are all closely related to Gnus.

*** Use the right dictionary

    One of the caveats of using two (or more) languages in a single
    installation of Gnus is that ispell sometimes gets confused. Having
    come across a stackoverflow question[fn:7] about just this subject
    it was easy to modify the source code posted there to come up with
    this.

    *Note:* See my [[Function declarations][note]] on function declarations about the use of
    =declare-function=.

    #+BEGIN_SRC emacs-lisp
      (declare-function message-narrow-to-headers-or-head "message")
      (declare-function message-fetch-field "message")

      (defun oni:switch-ispell-dictionary ()
        (save-excursion
          (message-narrow-to-headers-or-head)
          (when (string-match (rx (and "@" (or "aethon" "picturefix") ".nl>") eol)
                              (message-fetch-field "From"))
            (ispell-change-dictionary "nl_NL"))))

      (add-hook 'message-setup-hook 'oni:switch-ispell-dictionary)
    #+END_SRC

*** Don't let shr use background color

    Reading mail in Gnus is very nice, but shr has become a little too
    good at its job. Add to this the many occasions when a background is
    specified without specifying a foreground, plus a color theme that
    is the inverse of what is usually expected, and you can get
    hard-to-read HTML messages, gray foreground and gray background.

    I've looked at the other possible renderers, but they don't look
    very nice compared to shr. So just remove its ability to add
    background colors.

    *Note:* See my [[Function declarations][note]] on function declarations about the use of
    =declare-function=.

    #+BEGIN_SRC emacs-lisp
      (declare-function shr-colorize-region "shr")

      (defun oni:shr-colorize-remove-last-arg (args)
        "If ARGS has more than 3 items, remove the last one."
        (if (> (length args) 3)
            (butlast args)
          args))

      (with-eval-after-load 'shr
        (advice-add #'shr-colorize-region :filter-args
                    #'oni:shr-colorize-remove-last-arg))
    #+END_SRC

*** Init file

    I put my gnus initialization file right where I put all my
    module-specific initialization files. Gnus is special, though: It
    loads the file every time you start it. That keeps it from using a
    simple =(eval-after-load 'gnus '(load "gnus-init"))=.

    *Note:* See my [[Vacuous defvar][note]] on vacuous defvar for this use of =defvar=.

    #+BEGIN_SRC emacs-lisp
      (defvar gnus-init-file)
      (setq gnus-init-file "~/.emacs.d/site-lisp/gnus-init")
    #+END_SRC

** SQL

   This is a generic comint mode for multiple SQL implementations such
   as PostgreSQL and MariaDB (MySQL).

*** Remember SQL input

    Remembering input between sessions is a good thing.

    #+BEGIN_SRC emacs-lisp
      (stante-after sql
        (setf sql-input-ring-file-name
              (expand-file-name "~/.emacs.d/etc/sqliinput")))
    #+END_SRC

** Python

   I used to code Python for a living, that's not so much the case
   anymore. And for almost everything I will prefer Lisp over Python.
   So these customizations might be a little old or badly tested.

*** Show package name instead of file name

    When working with python, knowing which package I'm in usually tells
    me more about what I'm doing than the file name, especially when
    working with django where almost every app will have a ~tests.py~ and
    a ~models.py~. Of course =uniquify= fixes this pretty well too, though
    in this case, it's less cool (imo).

    First we define two functions that help us determine the package
    name of the current file and the parent package name of the current
    file. Finally we define a third function which determines the full
    package name of the current buffer.

    #+BEGIN_SRC emacs-lisp
      (defun oni:python--get-current-module-name ()
        "Get the name of the current python module.

      This is very simply just the filename of the current buffer with
      the extension and pyath removed."
        (file-name-sans-extension
         (file-name-nondirectory (buffer-file-name))))

      (defun oni:python--get-parent-module-name (&optional dir)
        "This gets the currend file's parent module.

      This function recursively gathers the parent package name of
      either DIR or the current buffer's file name. Any directory where
      an `__init__.py' file is found is considered to be a package.

      This function returns either the parent package, with its
      parents, or nil if the current directory isn't a python
      package.."
        (let* ((base (directory-file-name
                      (file-name-directory (or dir (buffer-file-name)))))
               (package (file-name-nondirectory base)))
          (if (file-exists-p (concat base "/__init__.py"))
              (let ((parent (oni:python--get-parent-module-name base)))
                (if parent
                    (concat parent "." package)
                  package))
            nil)))

      (defun oni:python-package-name ()
        (let ((current-module (oni:python--get-current-module-name)))
          (if (file-exists-p "__init__.py")
              (concat (oni:python--get-parent-module-name)
                      "." current-module)
            current-module)))
    #+END_SRC

    After all this we make Emacs show the package name rather than the
    file name in the mode-line.

    #+BEGIN_SRC emacs-lisp
      (defun oni:python-package-buffer-identification ()
        "Have `mode-line-buffer-identification' show the python package name."
        (setq mode-line-buffer-identification
              '(:eval (oni:python-package-name))))

      (add-hook 'python-mode-hook #'oni:python-package-buffer-identification)
    #+END_SRC

** Elnode

   Elnode is an awesome project and I'm still looking for a moment
   where I have the inspiration and time to actually do something with
   it. I started at some point, but then I couldn't get the cookies to
   work and I switched over to using Common Lisp, only to eventually
   stop developing the project because there was not chance of it
   seeing any use in the foreseeable future.

*** Don't start =elnode= when Emacs starts

    There is one little annoyance and that is the fact that elnode
    will start itself up when Emacs starts. I don't want that.

    This bit of code can't be put in an =eval-after-load= or anything
    like that because by the time it would be evaluated, elnode would
    already have started.

    *Note:* See my [[Vacuous defvar][note]] on vacuous defvar for this use of =defvar=.

    #+BEGIN_SRC emacs-lisp
      (defvar elnode-do-init)
      (setq elnode-do-init nil)
    #+END_SRC

** js2

   =js2-mode= isn't just an "improved" JavaScript mode, it's a full-on
   JavaScript parser. It's easy to notice typo's and such when Emacs
   can show you that a certain variable is or isn't declared. It does
   come with some baggage, as it's not immediately clear how I can
   specify which global names exist. For simple files it is fine to do
   something like:

   #+BEGIN_SRC js2 :tangle no
     /*global $ Routes jQuery */
   #+END_SRC

   Which will tell =js2-mode= that =$=, =Routes= and =jQuery= are known to be
   define elsewhere. This doesn't work well for big lists of globals.

*** Add some known symbols for .conkerorrc/init.js to js2-mode

    Conkeror has a lot of functions, and I don't like seeing them all as
    unknowns. So add them to known symbols.

    *Note:* See my [[Vacuous defvar][note]] on vacuous defvar for this use of =defvar=.

    #+BEGIN_SRC emacs-lisp
      (defvar js2-additional-externs)

      (defun oni:js2-add-conkeror-symbols ()
        "Add known/used conkeror symbols to additional externs."
        (when (string-suffix-p ".conkerorrc/init.js" (buffer-file-name))
          (setq js2-additional-externs
                '( ;; Functions
                  "add_hook" "check_buffer" "co_return" "content_buffer"
                  "define_browser_object_class" "define_key" "define_webjump"
                  "dumpln" "get_current_profile" "get_home_directory"
                  "get_recent_conkeror_window"
                  "hints_minibuffer_annotation_mode" "interactive" "load_spec"
                  "load_spec_uri_string" "load_url_in_new_buffer" "make_file"
                  "make_uri" "mode_line_adder"
                  "open_download_buffer_automatically" "prefix_completer"
                  "read_browser_object" "register_user_stylesheet"
                  "remove_hook" "require" "send_http_request" "session_pref"
                  "shell_command_blind" "theme_load"
                  ;; Variables
                  "Cc" "Ci" "browser_object_history_url" "browser_object_links"
                  "buffer_count_widget" "buffer_icon_widget" "content_buffer"
                  "content_buffer_form_keymap" "content_buffer_normal_keymap"
                  "content_buffer_text_keymap" "content_policy_accept"
                  "content_policy_bytype" "content_policy_reject" "cwd"
                  "default_base_keymap" "default_global_keymap"
                  "downloads_status_widget" "external_content_handlers"
                  "hint_digits" "load_paths" "read_buffer_show_icons"
                  "read_url_handler_list" "session_auto_save_auto_load"
                  "theme_load_paths" "title_format_fn" "url_remoting_fn"
                  ;; Keyword argument
                  "$alternative" "$browser_object" "$completer" "$completions"
                  "$initial_value" "$options" "$prompt" "$sort_order"
                  "$use_bookmarks" "$use_history" "$use_webjumps"))))

      (add-hook 'js2-init-hook #'oni:js2-add-conkeror-symbols)
    #+END_SRC

** Eww

   I've been excited about the "Emacs Web Wowser" since I first read
   about it on the mailing list. Previously I'd used some integration
   with w3 which was ok, but it certainly didn't match up to a
   fully-integrated Emacs application.

   This application uses =shr= just like Gnus, so there is some overlap
   here with reading Emails.

*** Teach eww about <code> tags

    Strangely enough, ~eww~ doesn't seem to be aware of =<code>= HTML tags.
    Luckily it's trivial to teach it. It does know about =<pre>= HTML
    tags, and basically I just want =<code>= tags to be treated almost as
    =<pre>= tags, so to do that we just have to define a =shr-tag-code=
    function. I've copied the =shr-tag-pre= function and removed the calls
    to =ensure-newline=, because =<code>= tags are inline tags.

    In order to remain a little future-proof, it should only be done if
    it doesn't already exist.

    *Note:* See my [[Vacuous defvar][note]] on vacuous defvar for this use of =defvar=.

    *Note:* See my [[Function declarations][note]] on function declarations about the use of
    =declare-function=.

    #+BEGIN_SRC emacs-lisp
      (defvar shr-folding-mode)
      (declare-function shr-indent "shr")
      (declare-function shr-generic "shr")

      (with-eval-after-load 'shr
        (unless (fboundp 'shr-tag-code)
          (defun shr-tag-code (cont)
            (let ((shr-folding-mode 'none))
              (shr-indent)
              (shr-generic cont)))))
    #+END_SRC

*** Setup eww-lnum

    #+BEGIN_SRC emacs-lisp :tangle no
      (depends-on "eww-lnum")
    #+END_SRC

    As recommended in the [[https://github.com/m00natic/eww-lnum][README]], set the keys in the =eww-mode-map=.

    #+BEGIN_SRC emacs-lisp
      (defvar eww-mode-map)

      (with-eval-after-load 'eww
        (define-key eww-mode-map "f" 'eww-lnum-follow)
        (define-key eww-mode-map "F" 'eww-lnum-universal))
    #+END_SRC

** Scheme

   I really like programming in Lisp. One of the more comfortable
   Lisps is Scheme because most of the implementations I've worked
   with are more like other compiled or interpreted languages, whereas
   Common Lisp usually re-compiles on every load. Aside from that,
   there are some neat programs written in some scheme dialects and of
   course scsh is the most awesome shell scripting language ever
   conceived.

*** Use scheme-mode for scsh interpreted files

    Set the major mode for files interpreted by scsh (for example, by
    having ~#!/usr/local/bin/scsh~ at the top) to use =scheme-mode=.

    #+BEGIN_SRC emacs-lisp
      (add-to-list 'interpreter-mode-alist '("scsh" . scheme-mode))
    #+END_SRC

*** Set default scheme implementation

    Set the default implementation for geiser to guile so it doesn't ask
    which implementation to use every time.

    #+BEGIN_SRC emacs-lisp
      (stante-after geiser-impl
        (setq geiser-default-implementation 'guile))
    #+END_SRC

** SCSS

   SCSS is a CSS preprocessor that makes writing CSS files much more
   fun. Add autocompletion and some custom imenu function.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'scss-mode-hook 'auto-complete-mode)
     (add-hook 'scss-mode-hook 'scss-imenu-setup)
   #+END_SRC

** Dired

   Dired is an excellent file manager.

*** Change listings in dired

    The number of bytes a file is doesn't usually tell me much when it's
    something like ~292837~. I prefer seeing just how many Kb or Mb a
    certain file is. I also don't need to see the ~.~ and ~..~ directories
    when I insert directories into the current dired buffer, as there is
    a great chance that the current and parent directory are already
    shown in the buffer.

    #+BEGIN_SRC emacs-lisp
      (defvar dired-subdir-switches)

      (with-eval-after-load 'dired
        (setq dired-listing-switches "-alh"
              dired-subdir-switches "-Alh"))
    #+END_SRC

** PHP

   I occasionally write PHP for work. Not usually in my free time, but
   there are some open source PHP projects that I sometimes tinker
   with.

*** Show tabs and spaces in indent

    I'm working with some WordPress plugins nowadays and their style
    guide insists on using tabs, not spaces... I'd like to know that
    I'm following this rule.

    #+BEGIN_SRC emacs-lisp
      (add-hook 'php-mode-hook #'oni:whitespace-only-tabs)
    #+END_SRC

** Web

   Web mode is good for files that contain a lot of HTML, CSS and
   JavaScript together. Most other major modes or multi-major modes
   don't quite do it.

*** Turn off the fill column indicator

    ~web-mode~ has some quirks, such as not being able to handle the
    fact that ~fci-mode~ puts a red line at the 80-column margin. This is
    annoying to say the least.

    #+BEGIN_SRC emacs-lisp
      (declare-function fci-mode "fci-mode")
      (add-hook 'web-mode-hook (turn-off fci-mode))
    #+END_SRC

*** Show tabs in indentation

    Just like in ~php-mode~ I want to see the tabs.

    #+BEGIN_SRC emacs-lisp
      (add-hook 'web-mode-hook #'oni:whitespace-only-tabs)
    #+END_SRC

*** Use tabs for indentation

    Set =indent-tabs-mode= for ~web-mode~ as well.

    #+BEGIN_SRC emacs-lisp
      (defvar web-mode-code-indent-offset)
      (defvar web-mode-markup-indent-offset)

      (add-hook 'web-mode-hook
                (change-settings indent-tabs-mode t
                                 web-mode-code-indent-offset 4
                                 web-mode-markup-indent-offset 4))
    #+END_SRC

*** Use it for Embedded Ruby HTML files

    Use it for ~.html.erb~ files.

    #+BEGIN_SRC emacs-lisp
      (oni:eval-after-init
        (add-to-list 'auto-mode-alist '("\\.html\\.erb$" . web-mode)))
    #+END_SRC

*** Use it for HTML-heavy PHP files

    I have to work with a lot of PHP and HTML interspersed. This makes
    a difficult case since ~php-mode~ very deliberately doesn't support
    that very well. On the other hand I really don't like ~web-mode~ for
    PHP /without/ any HTML in it. So I decided to name the files that
    contain mostly HTML with some PHP ~.html.php~ and have them load
    ~web-mode~ instead of ~php-mode~, whilst keeping the association for
    plain ~.php~ files as it is.

    Something tricky about doing this is that if this setting gets
    evaluated /before/ ~php-mode~ is loaded it'll be further down the list
    from ~php-mode~'s definition. This would cause the ~php-mode~ auto
    mode definition from being accepted first (since ~.html.php~ also
    matches ~.php~) and consequently render this definition useless.

    #+BEGIN_SRC emacs-lisp
      (oni:eval-after-init
        (add-to-list 'auto-mode-alist '("\\.html\\.php$" . web-mode)))
    #+END_SRC

** PO mode

   Autoload =po-mode=, because it didn't come with an autloads file or
   cookie.

   #+BEGIN_SRC emacs-lisp
     (autoload 'po-mode "po-mode" nil t)
   #+END_SRC

   Automatically enable =po-mode= for files that end in =.po= or that have
   a =.po= extension followed by others (such as =.po.erb=).

   #+BEGIN_SRC emacs-lisp
     (add-to-list 'auto-mode-alist '("\\.po\\'\\|\\.po\\." . po-mode))
   #+END_SRC

** Magit

   Recently Magit gained the annoying habit of producing a /huge/ warning
   message whenever you don't tell it that you've already seen it. To
   tell it you've already seen the message you need to specify the
   following.

   #+BEGIN_SRC emacs-lisp
     (eval-and-compile
       (defvar magit-last-seen-setup-instructions "1.4.0"))
   #+END_SRC

   I use a =defvar= here in order to keep the byte-compiler from
   complaining about an undefined variable. It needs to be specified
   before magit is loaded otherwise magit will keep complaining.

*** Project directory

    I keep all my projects in =~/projects/=, so Magit shouldn't have to
    look anywhere else.

    #+NAME: magit-repo-dirs
    #+BEGIN_SRC emacs-lisp :tangle no
      (setq magit-repository-directories '("~/projects/"))
    #+END_SRC

*** Show fine differences

    I like to see all the little differences in diffs that I can. They
    really help reading diffs. I also just want to see them on all
    diffs and not the selected one, which would make an unnecessary
    amount of navigation required to properly read the diffs.

    #+NAME: magit-diff-refine-hunk
    #+BEGIN_SRC emacs-lisp :tangle no
      (setq magit-diff-refine-hunk 'all)
    #+END_SRC

*** Delay setting

    The settings in the previous sections should only be set after
    Magit has loaded.

   #+BEGIN_SRC emacs-lisp :noweb yes
     (stante-after magit
       <<magit-repo-dirs>>
       <<magit-diff-refine-hunk>>)
   #+END_SRC

** Lui

   These settings will be tangled to =site-lisp/lui-init.el= and loaded
   when lui.el is loaded.

   #+BEGIN_SRC emacs-lisp
     (with-eval-after-load 'lui
       (require 'lui-init))
   #+END_SRC

** Circe

   These settings will be tangled to =site-lisp/circe-init.el= and
   loaded when Circe is loaded.

   #+BEGIN_SRC emacs-lisp
     (use-package circe
       :ensure t
       :commands (circe)
       :load-path "vendor-lisp/circe"
       :config (require 'circe-init))
   #+END_SRC

#+INCLUDE: init-circe.org :minlevel 3

** Twig

   Since twig is essentially a HTML template language, many tags must
   be edited. Tagedit is good for restructuring existing tag
   structures and adding single tags, whereas emmet mode is good when
   you know more about the HTML hierarchy you're going to add.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'twig-mode-hook 'tagedit-mode)
     (add-hook 'twig-mode-hook 'emmet-mode)
   #+END_SRC

   Since Twig is a /template/ language, and thus not just HTML, electric
   pairing is a blessing.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'twig-mode-hook 'electric-pair-local-mode)
   #+END_SRC

   Both HTML and Twig mode aren't traditional text modes, so
   =auto-fill-mode= doesn't make sense.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'twig-mode-hook (turn-off auto-fill-mode))
   #+END_SRC

** Ruby

   Turn on =abbrev-mode= in Ruby buffers.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'abbrev-mode)
   #+END_SRC

   Turn on [[Electric pair]] mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook #'electric-pair-local-mode)
   #+END_SRC

   Turn on [[Electric indent]] mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook #'electric-indent-local-mode)
   #+END_SRC

   Turn on [[Automatic syntax checking on-the-fly][Flycheck]] mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'flycheck-mode)
   #+END_SRC

   Turn on Yard mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'yard-mode)
   #+END_SRC

   Turn on [[Eldoc]] mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'eldoc-mode)
   #+END_SRC

   Turn on Ruby tools mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'ruby-tools-mode)
   #+END_SRC

   Turn on Ruby refactor mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'ruby-refactor-mode-launch)
   #+END_SRC

   Turn on [[Robe]] mode.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'robe-mode)
   #+END_SRC

   Set Fill Column Indicator column to the community Ruby Style Guide
   recommended value.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'ruby-mode-hook 'oni:ruby-set-rsg-margin)
   #+END_SRC

* Minor mode customization

  Many minor modes also offer a bit of customization possibilities.

** Robe

   #+BEGIN_SRC emacs-lisp :tangle no
     (depends-on "robe")
   #+END_SRC

   Robe is a Ruby completion and documentation lookup library.

** Eldoc

   Seeing the arguments to a function whilst typing its name is
   excellent.

*** Show eldoc when evaluating expressions

    Thanks to [[http://endlessparentheses.com/sweet-new-features-in-24-4.html][this post]] it was brought to my attention that eldoc mode
    can be enabled when evaluating expressions using {{{key(M-:)}}}.

    I vaguely remember having had this before, I just don't know how or
    why it stopped working.

    #+BEGIN_SRC emacs-lisp
      (add-hook 'eval-expression-minibuffer-setup-hook #'eldoc-mode)
    #+END_SRC

** Electric pair

   Electric pairing of delimiters is one of those features that is
   just so essential to my feeling comfortable with an editor. Most of
   the time I don't even use it, really. It's just that I'm so used to
   having it and when I /do/ expect it to be there it is so frustrating
   when it's not, or when it doesn't work properly.

   This functionality, much like [[Electric indent]] isn't something I
   want enabled in all modes, though for different reasons, and for a
   time there was only the global =electric-pair-mode=. Again I'm very
   happy that a local version was added.

   The reason that I don't want it enabled for all modes is that some
   modes (mostly Lisp-like language modes) have better alternatives.
   But most non-Lisp-like language modes I really do need to have it.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'c-mode-hook #'electric-pair-local-mode)
     (add-hook 'coffee-mode-hook #'electric-pair-local-mode)
     (add-hook 'css-mode-hook #'electric-pair-local-mode)
     (add-hook 'haml-mode-hook #'electric-pair-local-mode)
     (add-hook 'java-mode-hook #'electric-pair-local-mode)
     (add-hook 'lua-mode-hook #'electric-pair-local-mode)
     (add-hook 'python-mode-hook #'electric-pair-local-mode)
     (add-hook 'scss-mode-hook #'electric-pair-local-mode)
     (add-hook 'sh-mode-hook #'electric-pair-local-mode)
   #+END_SRC

*** Remove whitespace when closing delimiters

    In =electric-pair-mode=, skip over and delete white space if it stands
    between the cursor and the closing delimiter.

    #+BEGIN_SRC emacs-lisp
      (setq electric-pair-skip-whitespace 'chomp)
    #+END_SRC

** Electric indent

   Automatically indenting code upon typing certain characters can be
   very useful for certain modes where the indentation level can
   easily be determined. One of the first things I liked about Emacs
   was the way the {{{key(TAB)}}} key worked: It indents to the
   "proper" level of indentation, instead of adding a tab character.
   It quickly grew into a habit to press tab several times when
   editing a line or a block of code. Electric indent is just an
   extension of this that, for the most part, allows me to forget
   about pressing tab.

   It doesn't fit all modes though. When I worked in Python a lot I
   was fighting the electric indent a lot more than it was helping me.
   This is because instead of scope influencing indentation as in most
   languages I've worked with, indentation determines scope in Python,
   as anyone who's looked at it for more than a minute or two will
   know. This means that any line can usually have several "proper"
   indentation levels, depending on the meaning of meaning of that
   line.

   So, almost all modes use =electric-indent-local-mode=, but a few
   don't. So I'm also very happy that recently this mode was added,
   because =electric-indent-mode= is a global minor mode and I only want
   to use it in some 99% of the available modes.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'css-mode-hook #'electric-indent-local-mode)
     (add-hook 'php-mode-hook #'electric-indent-local-mode)
     (add-hook 'scss-mode-hook #'electric-indent-local-mode)
     (add-hook 'sh-mode-hook #'electric-indent-local-mode)
   #+END_SRC

*** Switch keys back

    When =electric-indent-mode= is enabled the default function bound to
    {{{key(C-j)}}} (=electric-newline-and-maybe-indent=) stops indenting
    after adding a newline, whilst {{{key(RET)}}} starts doing it.
    Since I use {{{key(C-j)}}} almost exclusively and don't use
    {{{key(RET)}}} at all, it's really not useful to me. So I want to
    switch the two when =electric-indent-mode= is enabled.

    This is very simple. First I define a simple function that checks
    if the =electric-indent-mode= variable is set (which it should be if
    the mode is turned on) and if so I set the proper keys /locally/. If
    =electric-indent-mode= is /not/ set, which happens when the mode is
    turned off, I remove the local keybindings.

    #+BEGIN_SRC emacs-lisp
      (defun oni:switch-newline-keys ()
        "Switch the `C-j' and `RET' keys in the local buffer."
        (if electric-indent-mode
            (progn
              (local-set-key (kbd "C-j") 'newline)
              (local-set-key (kbd "RET") 'electric-newline-and-maybe-indent))
          (local-unset-key (kbd "C-j"))
          (local-unset-key (kbd "RET"))))
    #+END_SRC

    And then I add it to the electric indent mode's hook.

    #+BEGIN_SRC emacs-lisp
      (add-hook 'electric-indent-local-mode-hook #'oni:switch-newline-keys)
    #+END_SRC

** Auto completion

   #+BEGIN_SRC emacs-lisp :tangle no
     (depends-on "auto-complete")
   #+END_SRC

   I'm not a great fan of any type of auto completion functionality in
   programming. I think it's basically only good for getting really
   long names in your file faster. I started programming in C#, in
   Visual Studio, and they have their very powerful Intellisense
   mechanism, which I used a lot. What I noticed though was that it
   was keeping me from learning the APIs. Whenever I wrote some code,
   all but the most basic and most-used calls I wrote from memory.
   Many others were done after a few seconds of browsing through the
   Intellisense pop-up.

   Because of this, I disable the normal auto-complete pop-up.

   #+NAME: auto-complete-dont-show
   #+BEGIN_SRC emacs-lisp :tangle no
     (setq ac-auto-show-menu nil)
   #+END_SRC

   On the rare occasion that I do call up the pop-up to see what the
   completions I have available to me are, I don't want it to show the
   quick help. The quick help usually shows up as a big extra pop-up
   next to the completion list and it gets very messy when combined
   with some other modes that add overlays to the buffer.

   #+NAME: auto-complete-no-quickhelp
   #+BEGIN_SRC emacs-lisp :tangle no
     (setq ac-use-quick-help nil)
   #+END_SRC

   To keep the byte-compiler from complaining about undefined
   variables, I only want this to be done after =auto-complete= is
   loaded, not sooner.

   #+BEGIN_SRC emacs-lisp :noweb yes
     (stante-after auto-complete
       <<auto-complete-dont-show>>
       <<auto-complete-no-quickhelp>>)
   #+END_SRC

** Highlight indentation

   #+BEGIN_SRC emacs-lisp :tangle no
     (depends-on "hl-indent")
   #+END_SRC

   Some languages base their ideas of scope on levels of indentation.
   When these languages get long functions/branches it can get tricky
   to see where these blocks end. Of course if you have such large
   functions you might have other problems, but this is sometimes out
   of your hands. To help, I use =hl-indent-mode=.

   For other languages it might look fun for a little while as well,
   but since they don't care about indentation as much it can
   sometimes get messy.

   First, =hl-indent-mode= doesn't have an =;;;###autoload= cookie for its
   main entry-point, so I add it manually:

   #+BEGIN_SRC emacs-lisp
     (autoload 'hl-indent-mode "hl-indent" nil t)
   #+END_SRC

   Then I enable it for the languages I want.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'python-mode-hook #'hl-indent-mode)
     (add-hook 'yaml-mode-hook #'hl-indent-mode)
     (add-hook 'haml-mode-hook #'hl-indent-mode)
   #+END_SRC

** Django helper
   :PROPERTIES:
   :ORDERED:  t
   :END:

   #+BEGIN_SRC emacs-lisp :tangle no
     (depends-on "pony-mode")
   #+END_SRC

   Autoload =pony-mode= because it doesn't come with an autoload cookie.

   #+BEGIN_SRC emacs-lisp
     (autoload 'pony-mode "pony-mode" nil t)
   #+END_SRC

   Turn on =compilation-shell-minor-mode= when =pony-mode= is enabled.

   #+BEGIN_SRC emacs-lisp
     (defun oni:turn-on-compilation-shell-for-pony ()
       "Turn on option `compilation-shell-minor-mode' for `pony-minor-mode'."
       (add-hook 'pony-minor-mode-hook 'compilation-shell-minor-mode nil t))

     (add-hook 'comint-mode-hook #'oni:turn-on-compilation-shell-for-pony)
   #+END_SRC

** Automatic syntax checking on-the-fly

   #+BEGIN_SRC emacs-lisp :tangle no
     (depends-on "flycheck")
     (depends-on "flycheck-cask")
     (depends-on "flycheck-commit-check" :git "git://github.com/ryuslash/flycheck-commit-check.git")
   #+END_SRC

   Flycheck provides awesome syntax checkers for many languages.
   Enable it for the languages I use.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'haml-mode-hook 'flycheck-mode)
     (add-hook 'emacs-lisp-mode-hook 'flycheck-mode)
     (add-hook 'git-commit-mode-hook 'flycheck-mode)
     (add-hook 'go-mode-hook 'flycheck-mode)
     (add-hook 'html-mode-hook 'flycheck-mode)
     (add-hook 'lua-mode-hook 'flycheck-mode)
     (add-hook 'perl-mode-hook 'flycheck-mode)
     (add-hook 'php-mode-hook 'flycheck-mode)
     (add-hook 'python-mode-hook 'flycheck-mode)
     (add-hook 'rst-mode-hook 'flycheck-mode)
     (add-hook 'rust-mode-hook 'flycheck-mode)
     (add-hook 'sh-mode-hook 'flycheck-mode)
     (add-hook 'texinfo-mode-hook 'flycheck-mode)
   #+END_SRC

   Whenever flycheck is started, try using it with Cask.

   #+BEGIN_SRC emacs-lisp
     (add-hook 'flycheck-mode-hook 'flycheck-cask-setup)
   #+END_SRC

   Load my own git commit checker.

   #+NAME: flycheck-commit-checker
   #+BEGIN_SRC emacs-lisp :tangle no
     (require 'flycheck-commit-check)
   #+END_SRC

   Disable certain checkers.

   #+NAME: flycheck-delete-checkers
   #+BEGIN_SRC emacs-lisp :tangle no
     (mapc (lambda (c) (delq c flycheck-checkers))
           '(python-pylint python-pyflakes))
   #+END_SRC

   Set the highlighting mode to columns so I can see (if possible)
   where errors/warnings belong.

   #+NAME: flycheck-columns
   #+BEGIN_SRC emacs-lisp :tangle no
     (setq flycheck-highlighting-mode 'columns)
   #+END_SRC

   Try not to display the errors. A jumpy echo area makes me nervous
   and {{{key(C-c ! l)}}} is a nicer way to look at it usually. It
   still doesn't keep it from being displayed, only when nothing else
   is displayed though.

   #+NAME: flycheck-display
   #+BEGIN_SRC emacs-lisp :tangle no
     (setq flycheck-display-errors-function (lambda (_) nil))
   #+END_SRC

   Do most of these things after flycheck is loaded.

   #+BEGIN_SRC emacs-lisp :noweb yes
     (stante-after flycheck
       <<flycheck-commit-checker>>
       <<flycheck-delete-checkers>>
       <<flycheck-columns>>
       <<flycheck-display>>)
   #+END_SRC

** Hightlight numbers mode

   I find this regular expression to work better at identifying
   general numbers as the default one doesn't consider numbers
   starting with a sign or a decimal point.

   #+BEGIN_SRC emacs-lisp
     (stante-after highlight-numbers
       (setq highlight-numbers-generic-regexp
             "\\_<[-+]?[[:digit:]]+\\(?:\.[[:digit:]]+\\)?.*?\\_>"))
   #+END_SRC

** Emmet mode

   I'm one of the strange people who use {{{key(C-j)}}} instead of
   {{{key(RET)}}} to insert a new line (and indent), so Emmet mode's
   default binding of using {{{key(C-j)}}} to expand a line is very
   disruptive to me.

   #+BEGIN_SRC emacs-lisp
     (stante-after emmet-mode
       (define-key emmet-mode-keymap (kbd "C-j") nil)
       (define-key emmet-mode-keymap (kbd "RET") #'emmet-expand-line))
   #+END_SRC

* Applications

  Emacs has a number of packages that are basically applications
  within Emacs. These are the ones I use or have used in the past, and
  may again use in the future.

** Elfeed

   #+BEGIN_SRC emacs-lisp
     (use-package elfeed
       :ensure t
       :defer t)
   #+END_SRC

* Final touches

  These options and calls need to come last so they don't interfere
  with the rest of the initialization process, or get interfered with.

** Load custom file

   I don't really use the Emacs customization interface much, but I
   have used it as a kind-of persistent datastore, specifically for
   desktop-registry[fn:9]. I do very much like the idea of it, it's a
   very cool thing to have. I also use ~custom.el~ for storing some
   things that I really can't store in a public viewing location like
   this file or the git repository it lives in.

   #+BEGIN_SRC emacs-lisp
     (setq custom-file "~/.emacs.d/custom.el")
     (load custom-file)
   #+END_SRC

* Notes

  Here are some random or somewhat general notes about things you may
  run into when looking through my Emacs init.

** Vacuous defvar

   A =defvar= without a value like =(defvar some-variable)= tells the
   byte-compiler that the variable will appear, but doesn't give it a
   value. It should only count for the file where it is used and once
   the file with the /actual/ =defvar= is loaded it will be populated with
   its value, contrary to what would happen if you'd given it a value
   before loading its original file.

** Function declarations

   The function =declare-function= tells the byte-compiler where to find
   a certain function. This keeps the byte-compiler from complaining
   about certain functions possibly not being defined at run-time.

* Footnotes

[fn:1] This runs =tmm-menubar=, which lets you navigate the menubar in a
  text-driven way. I don't ever use it because I know what all my
  favorite functions are called, but it seems a great deal more
  efficient than having to click on everything.

[fn:2] https://github.com/sabof/svg-mode-line-themes

[fn:3] It works fine for me with something like jabber chats and the
  like.

[fn:4] I like to program in Lisp, parentheses are important to me!
  Parentheses should be nice and round, not almost like bars!

[fn:5] https://github.com/belluzj/fantasque-sans

[fn:6] Used to be Cosmic Sans Neue Mono, the name changed because
  people misread it as "Comic" (me included, which was the original
  reason I checked it out, for laughs) and hate Comic Sans, and also
  because there was already a Cosmic Sans font as well, which could
  cause confusion.

[fn:7] http://stackoverflow.com/questions/22175214/automatically-switch-language-in-gnus-depending-on-recipient

[fn:8] I still use 2 spaces for some languages, like HTML.

[fn:9] http://code.ryuslash.org/desktop-registry/about/