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

#+TITLE: Emacs init
#+PROPERTY: tangle init2.el
#+STARTUP: showall
#+OPTIONS: author:nil num:nil toc:nil
#+MACRO: key   @@html:<kbd>$1</kbd>@@@@ascii:`$1'@@
#+HTML_HEAD: <link href="https://ryuslash.org/org.css" rel="stylesheet" type="text/css">

* About this file

  Inspired by such other projects as the literal Emacs init from [[http://sachac.github.io/.emacs.d/Sacha.html][Sacha
  Chua]] and also from [[http://www.wisdomandwonder.com/wordpress/wp-content/uploads/2014/03/C3F.html][Grant Rettke]], here is my Emacs initialization
  file.

  *Note:* This is not my entire Emacs initialization file. It's a
  work-in-progress. To keep on top of any changes to this file, or any
  other part of my Emacs init, I recommend you follow [[http://code.ryuslash.org/dot/tom/emacs/][This project]]
  ([[http://code.ryuslash.org/dot/tom/emacs/atom/?h=master][Atom feed]]), which is where I keep my configuration.

** Preparation

   I could use org-babel to load this file, but I don't like my
   initialization file being dependent on too many things, especially
   big things, and org is a big thing. 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 it's org-mode 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've 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.

* Use lexical binding

  For some of these functions, and general coolness, lexical binding
  is a must. Without it, closures cannot be made.

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

* 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

* Clean up some UI elements

  Some elements are only really useful if you use the mouse. Which I
  don't, not if I can help it. Only when browsing the web or using the
  odd graphical application do I touch the mouse, and even then as
  little as I can.

** 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

** 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

** 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

** 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

** 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

** 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

** Cursors in inactive windows

   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

** 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

** The default frame

   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.

*** Internal border

   Set the internal border width to 0. This makes a small difference,
   with my current setup it causes my window's width to increase from
   120 to 121. Small, I know, but I'm very greedy when it comes to
   screen space.

   #+NAME: default-frame-internal-border
   #+BEGIN_SRC emacs-lisp :tangle no
     (internal-border-width . 0)
   #+END_SRC

*** 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 13" 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:pixelsize=17")
    #+END_SRC

*** 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

*** Setting the option

    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-internal-border>>
              <<default-frame-font>>
              <<default-frame-scroll-bar>>))
    #+END_SRC

** 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

* 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

* 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 {{{kbd(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

* Stumpwm integration

  This variable, macro and function help with integrating Emacs and
  Stumpwm. They are used by some other functions to make the two seem
  extra connected.

  #+BEGIN_SRC emacs-lisp
    (defvar oni:stumpish-program
      (expand-file-name
       "~/.local/share/quicklisp/local-projects/stumpwm/contrib/util/stumpish/stumpish")
      "The location of the stumpish executable.")

    (defmacro oni:stumpwm (&rest body)
      "Execute BODY in stumpwm."
      (declare (indent 0))
      `(call-process oni:stumpish-program nil nil nil
                     ,(format "eval '%S'" `(progn ,@body))))

    (defun oni:stumpwm-command (cmd)
      "Execute CMD in stumpwm."
      (call-process oni:stumpish-program nil nil nil cmd))

    (defun oni:stumpwm-echo (message)
      (call-process oni:stumpish-program nil nil nil (format "echo %s" message)))
  #+END_SRC

** Fall back on stumpwm when moving around

   Using the function specified in [[Stumpwm integration]] wrap the
   =windmove-do-window-select= function and catch any error produced,
   hoping it's the error that there's no more window to move to and
   then request that stumpwm move the focus in the same direction as
   windmove would have.

   #+BEGIN_SRC emacs-lisp
     (defadvice windmove-do-window-select
         (around oni:windmove-stumpwm activate)
       "If no window can be moved to, move stumpwm."
       (condition-case err
           ad-do-it
         (error (oni:stumpwm-command
                 (format "move-focus %s" (ad-get-arg 0))))))
   #+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

* 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"))))

    (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

* 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

* 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/sqliinput")))
  #+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

* 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

* 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 {{{kbd(RET)}}}, give me a simple
  ~y~ or ~n~ with no {{{kdb(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/"
              "~/.emacs.d/vendor-lisp/habitrpg.el")))
  #+END_SRC

* Some unconditional settings

  Here are some settings that either need to be changed before certain
  modules load, or that don't belong in any specific module.

** Gnus 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

** 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

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

   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.

   There is one little annoyance, though, 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

* Show python 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

* 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

* 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

* 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
    (defvar geiser-default-implementation)

    (with-eval-after-load 'geiser
      (setq geiser-default-implementation 'guile))
  #+END_SRC

* Setup eww-lnum

  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

* Don't compile scss files

  By default =scss-mode= tries compiling a file each time it's saved. I
  don't have SCSS properly installed globally so this always fails,
  highly annoying.

  #+BEGIN_SRC emacs-lisp
    (defvar scss-compile-at-save)

    (with-eval-after-load 'scss-mode
      (setq scss-compile-at-save nil))
  #+END_SRC

* 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

* 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 (in-string-p)
         (error "You must be in a string for this command to work"))

       (save-excursion
         (while (in-string-p) (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

* 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

* Return to {{{key(C-j)}}} in electric indent mode

  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 when =electric-indent-mode=
  is enabled, switch the two.

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

* Local minor mode for =electric-pair-mode=

  Almost all modes benefit from automatic delimiter pairing, but not
  all modes are equal. =paredit= works awesomely for anything lisp-like,
  but not so much for other modes, that's where =electric-pair-mode=
  comes in. Unfortunately it has no local version, so I copied the
  code from =electric-indent-local-mode= and changed it work with
  =electric-pair-mode=.

  #+BEGIN_SRC emacs-lisp
    ;; Copied from electric.el, modified from `electric-indent-local-mode'.
    (define-minor-mode oni:electric-pair-local-mode
      "Toggle `electric-pair-mode' only in this buffer."
      :variable (buffer-local-value 'electric-pair-mode (current-buffer))
      (cond
       ((eq electric-pair-mode (default-value 'electric-pair-mode))
        (kill-local-variable 'electric-pair-mode))
       ((not (default-value 'electric-pair-mode))
        ;; Locally enabled, but globally disabled.
        (electric-pair-mode 1)                ; Setup the hooks.
        (setq-default electric-pair-mode nil) ; But keep it globally disabled.
        )))
  #+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

* 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

* Programming

  Emacs is a real programmer's editor, especially so because it's so
  programmable itself. It also offers modes for a lot of programming
  languages and 3rd-party packages offer even more.

** SCSS

   - Automatically match parentheses and other delimiters.

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

   - Automatically indent code.

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

** Haml

   - Automatically match parentheses and other delimiters.

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

** Ruby

   - Automatically match parentheses and other delimiters.

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

   - Enable flycheck

     #+BEGIN_SRC emacs-lisp
       (declare-function flycheck-mode "flycheck")

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

   - Align chained method calls

     #+BEGIN_SRC emacs-lisp
       (defvar ruby-align-chained-calls)

       (setq ruby-align-chained-calls t)
     #+END_SRC


** Coffee

   - Automatically match parentheses and other delimiters.

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

** PHP

   - Automatically indent code

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

*** 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
      (defun oni:enable-whitespace-for-php ()
        (setq whitespace-style '(face tabs tab-mark))
        (whitespace-mode))

      (add-hook 'php-mode-hook #'oni:enable-whitespace-for-php)
    #+END_SRC

* 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/