Look at a few interesting features that comes by default

Introduction

Emacs has a great ecosystem of plugins. Whether you’re doing web stuff, python or put the language you want here, you need tools and that’s when emacs plugins becomes handy. Autocompletion, jump to defintion and other fancy features are some of the features you can expect for most of the programming languages using the plugin ecosystem.

This post will be about tailoring emacs to make it behave more like an IDE tailored for your programming needs and install things that will make emacs even better

How do we install plugins

There’s 2 way to install things on emacs:

  1. rely on emacs package manager
  2. install things manually

Emacs package manager

That’s the generally accepted way to do it. To start installing packages with the package manager:

M-x package-refresh-contents
M-x package-install => then tab to see all the available packages and select the one you want

Tips: If you’re behind a proxy, open your configuration (if you’re using the configuration given in episode 1), uncomment the very first lines (F4 or M-x uncomment-region) and fill in your company proxy details:

;; SETUP YOUR PROXY IF NEEDED
;; (setq url-proxy-services
;;       '(("no_proxy" . "^\\(localhost\\|10.*\\)")
;;         ("http" . "company.com:8080")
;;         ("https" . "company.com:8080")))

Install things manually

Why you would ever do that

It’s not the general way of doing things as most package advise you to go with the package manager but despite this, I usually install plugins by hand. Here is why:

  • I prefer to keep control over what to load, when and how. That way, I won’t ever be one of those many people:
  • I prefer to have a one line copy paste install approach that will also configure the plugin in the way I want and keep those separate so that I can quickly get rid of stuff and add more on the fly.
  • I always have issues with the package manager while I’m at work behind our very restrictive company proxy. Yes it happens, my company even put a warning message when I downloaded emacs saying this software could be dangerous (no joke).

How to do it

Installing a plugin by hand usually boils down to:

  1. get the code of your plugin and extract it somewhere
  2. If needed, get any dependency code and extract it somewhere
  3. setup the plugin so that you can actually use it.

Installing a plugin usually end up following those steps:

  • make emacs know where to lookup for the plugin and its dependencies:
(add-to-list 'load-path "~/.emacs.d/plugins/my-great-plugin")
  • load the plugin so that you can use it. There’s 2 approach to load it:
# approach 1: instantiate the plugin right away
(require 'my-super-plugin)
# approach 2: lazy load plugin instantiation
(autoload 'my-super-plugin "my-super-plugin" "super login mode" t)

Avoid the slow booting curse

  1. The thumb rule

    There’s way too many horror stories where people claim to have emacs booting up in 30s (I even saw someone who were claiming an amazing 30 minutes!). It won’t happen to you if you follow this simple rule of thumb: Is your plugin absolutely necessary when emacs starts? => yes: use require => no: use lazyloading

    If you use require, you pay the plugins loading time upfront when emacs boots up. With lazy loading, you only pay for it when you need it. It might seem obvious but it’s very easy to endup with a bloated configuration. Personally my emacs typical booting time is 0.6 second (‘M-x emacs-init-time’). Still I got quite a lot of stuff in there. How I do it is simple, everytime I download something, I just apply the rule of thumb above.

  2. Lazy loading

    If I found out I can lazy load something I just do it like this:

    (autoload 'cool-plugin-for-org-mode "cool-plugin-for-org-mode" "cool plugin for org mode" t)
    (add-hook 'org-mode-hook 'cool-plugin-for-org-mode)
    

    Essentially, it means that when org mode is loaded, my plugin is getting load and I pay for its loading cost only when I need it.

    There’s another class of plugin that you would want to use only when you press certain keys (think like project navigation, a git client, multiple cursors or any plugins not related to what your actual major mode is):

    (autoload 'cool-mode "cool-mode" "cool mode" t)
    (global-set-key (kbd "C-c C-z") 'cool-mode)
    

How do I structure my emacs

To keep things separate, my emacs configuration is separate from the plugin configuration. Basically the .emacs.d has this structure:

.emacs.d
|- init.el
|- conf
   |- conf_1.el (configuration something very specific)
   |- conf_2.el (configuration for a plugin)
   |- ...
|- plugins
   |- deps (contains all dependencies used by all plugins)
   |- plugin 1 (source code of plugin 1)
   |- plugin 2 (source code of plugin 2)
   |- ...

You might be worry that all dependencies are shared among all plugins (especially if you have some background in node) but I never had any issues with this structure. Maybe not having dependencies which called hundreds of dependencies which also have their own set of dependencies isn’t what you’ll typically see with emacs.

Assumptions

If you don’t want to start with the configuration given in episode 1 but want to keep going with this series of posts, you’ll have to at least execute those commands:

mkdir -p ~/.emacs.d/plugins/dep ~/.emacs.d/conf
# replace init.el by what your actual emacs configuration file if needed
cat > ~/.emacs.d/init.el <<EOF
(mapc
 (lambda(path) (load-file path))
 (directory-files "~/.emacs.d/conf/" t "\.el$"))
EOF

What this does is:

  1. create a folder to store all your plugins and their dependencies.
  2. create a configuration folder called ‘conf’ where you can drag and drop all your plugin related configuration or anything else that you think isn’t related to your core emacs conf. You’ll end up with a clear separation between the configuration of plugins and emacs core config.

Plugins I use

Git client: Magit

We’ll assume you’re using git for version control. Magit is the best solution in the emacs ecosystem to manage your git repository directly from emacs:

To install:

mkdir -p ~/.emacs.d/plugins/ ~/.emacs.d/plugins/deps && cd ~/.emacs.d/plugins/
git clone -b '2.10.3' --single-branch --depth 1 https://github.com/magit/magit
cd ./deps
git clone -b '2.13.0' --single-branch --depth 1 https://github.com/magnars/dash.el
git clone -b 'v2.5.10' --single-branch --depth 1 https://github.com/magit/with-editor
cd ~/.emacs.d/plugins/magit

cat > config.mk <<EOF
LOAD_PATH = -L ~/.emacs.d/plugins/deps/dash.el
LOAD_PATH += -L ~/.emacs.d/plugins/deps/with-editor
LOAD_PATH += -L ~/.emacs.d/plugins/magit/lisp
EOF
make

cat > ~/.emacs.d/conf/magit.el <<EOF
;; begin(magit)
(autoload 'magit-status "magit" "Magit mode" t)
(add-to-list 'load-path "~/.emacs.d/plugins/magit/lisp")
(add-to-list 'load-path "~/.emacs.d/plugins/deps/dash.el")
(add-to-list 'load-path "~/.emacs.d/plugins/deps/with-editor")
(global-set-key (kbd "C-c g") 'magit-status)
;; end(magit)
EOF

Reference: the repo

Undo/redo done right: Undo tree

On our everydays regular applications, undo redo is linear but it shouldn’t be. The actual change flow comes to navigate in a tree of change. That’s what undo tree is all about:

Installation:

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins/
git clone --single-branch --depth 1 https://github.com/emacsmirror/undo-tree

cat > ~/.emacs.d/conf/undo-tree.el <<EOF
;; begin(undo-tree)
(add-to-list 'load-path "~/.emacs.d/plugins/undo-tree")
(global-set-key (kbd "C-c C-z") 'undo-tree-visualize)
(autoload 'undo-tree-visualize "undo-tree" "undo-tree mode" t)
;; end(undo-tree)
EOF

you now have fine control of the undo/redo operation with C-c z

Reference: the repo

Project navigation: Projectile

Porjectile makes it easy to navigate in a project:

Installation:

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins/
git clone -b 'v0.14.0' --single-branch --depth 1 https://github.com/bbatsov/projectile

cat > ~/.emacs.d/conf/projectile.el <<EOF
;; begin(projectile)
(add-to-list 'load-path "~/.emacs.d/plugins/projectile")
(autoload 'projectile-find-file "projectile" "Projectile mode" t)
(autoload 'projectile-grep "projectile" "Projectile mode" t)
(setq projectile-indexing-method 'alien)
(global-unset-key (kbd "C-c C-f"))
(global-unset-key (kbd "C-c C-g"))
(global-set-key (kbd "C-c C-f") 'projectile-find-file)
(global-set-key (kbd "C-c C-g") 'projectile-grep)
;; end(projectile)
EOF

If you’re inside a project, it can be pretty boring to open a file with the typical C-x C-f. Introducing C-c C-f to find a file in your project more efficiently and C-c C-g to find files based on a string in this file.

Reference: the repo

Programming environment I have used in emacs

Clojure: Cider

Reference: the repo

PHP

Reference: the repo

Elixir

mkdir -p ~/.emacs.d/plugins/ ~/.emacs.d/plugins/deps && cd ~/.emacs.d/plugins/
git clone -b 'v1.8.1' --single-branch --depth 1 https://github.com/tonini/alchemist.el
git clone -b 'v2.3.1' --single-branch --depth 1 https://github.com/elixir-lang/emacs-elixir
cd deps/
git clone -b '0.6' --single-branch --depth 1 https://github.com/lunaryorn/pkg-info.el
git clone -b '0.8' --single-branch --depth 1 https://github.com/cask/epl

cat > ~/.emacs.d/conf/elixir.el <<EOF
;; begin(elixir)
(add-to-list 'load-path "~/.emacs.d/plugins/alchemist.el")
(add-to-list 'load-path "~/.emacs.d/plugins/emacs-elixir")
(add-to-list 'load-path "~/.emacs.d/plugins/deps/pkg-info.el")
(add-to-list 'load-path "~/.emacs.d/plugins/deps/epl")
(autoload 'alchemist "alchemist" "alchemist mode" t)
(add-to-list 'auto-mode-alist '("\.ex$" . markdown-mode))
(add-to-list 'auto-mode-alist '("\.exs$" . markdown-mode))
(add-to-list 'auto-mode-alist '("\.html$" . html-mode))
;; end(elixir)
EOF

Reference: the repo

Other Web stuff

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins/
git clone -b 'v14.1' --single-branch --depth 1 https://github.com/fxbois/web-mode

cat > ~/.emacs.d/conf/web-mode.el <<EOF
;; begin(web-mode)
(add-to-list 'load-path "~/.emacs.d/plugins/web-mode")
(autoload 'web-mode "web-mode" "Web mode" t)
(add-to-list 'auto-mode-alist '("\.scss$" . css-mode))
(add-to-list 'auto-mode-alist '("\.less$" . css-mode))
(add-hook 'html-mode-hook 'web-mode)
;; end(web-mode)
EOF

Reference: the repo

Edit Markdown: Markdown mode

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins/
git clone -b 'v2.1' --single-branch --depth 1 https://github.com/jrblevin/markdown-mode

cat > ~/.emacs.d/conf/markdown-mode.el <<EOF
;; begin(markdown-mode)
(autoload 'markdown-mode "markdown-mode" "Markdown mode" t)
(add-to-list 'load-path "~/.emacs.d/plugins/markdown-mode")
(add-to-list 'auto-mode-alist '("\.markdown$" . markdown-mode))
(add-to-list 'auto-mode-alist '("\.md$" . markdown-mode))
(add-hook 'text-mode-hook 'flyspell-mode)
;; end(tern)
EOF

Reference: the repo

Autocomplete

Autocomplete: Company mode

Company mode is a completion framework for emacs. It ships with different backend that let you autocomplete on different things by default. Of course you can extend it to work with the language you want, at least if you succeed to make it work.

mkdir -p ~/.emacs.d/plugins/ ~/.emacs.d/plugins/deps && cd ~/.emacs.d/plugins
git clone -b '0.9.2' --single-branch --depth 1 https://github.com/company-mode/company-mode

cat > ~/.emacs.d/conf/company-mode.el <<EOF
;; begin(company-mode)
(add-to-list 'load-path "~/.emacs.d/plugins/company-mode")
(autoload 'company-mode "company" "Company mode" t)
;; end(company-mode)
EOF

Reference: the repo

Javascript: Tern

Tern is a great autocompletion for js

mkdir -p ~/.emacs.d/plugins/ ~/.emacs.d/plugins/deps && cd ~/.emacs.d/plugins
git clone -b '0.12.0' --single-branch --depth 1 https://github.com/ternjs/tern/
cd tern && npm install
cd ~/.emacs.d/plugins/deps
git clone -b 'v0.5.3' --single-branch --depth 1 https://github.com/auto-complete/

cat > ~/.emacs.d/conf/tern.el <<EOF
;; begin(tern)
(defun load-tern ()
  (setenv "PATH" (concat "/usr/local/bin:" (getenv "PATH")))
  (add-to-list 'load-path "~/.emacs.d/plugins/tern/emacs")
  (add-to-list 'load-path "~/.emacs.d/plugins/deps/popup-el")
  (add-to-list 'load-path "~/.emacs.d/plugins/deps/auto-complete")
  (autoload 'tern-mode "tern.el" nil t)
  (eval-after-load 'tern
    '(progn
       (require 'auto-complete-config)
       (ac-config-default)
       (require 'tern-auto-complete)
       (tern-ac-setup)))
  (add-hook 'js-mode-hook (lambda () (tern-mode t))))
(add-hook 'after-init-hook 'load-tern)
;; end(tern)
EOF

cat > ~/.tern-config <<EOF
{
    "plugins": {
        "node": {},
        "es_modules": {}
    },
    "libs": [
        "ecma5",
        "ecma6"
    ],
    "ecmaVersion": 6
}
EOF

Note, there’s a autocomple plugin for tern too but I couldn’t make it work so I went with autocomplete instead.

Reference: the repo

Email: wanderlust

An email client for emacs:

Emacs comes with a builtin mode for email called gnus but I have found wanderlust to do better job at it. Because the proxy won’t let me use email at work, i use the package manager to install wanderlust

M-x package-refresh-contents
M-x package-install wanderlust

Setup:

cat > ~/.folders <<EOF
# -*- conf-unix -*-
GMAIL{
  %INBOX:"mickael.kerjean"/clear@imap.gmail.com:993!    "In"
  %[Gmail]/Sent Mail:"mickael.kerjean"/clear@imap.gmail.com:993!        "Sent"
}
PERSO{
  %INBOX:"mickael@kerjean.me"@SSL0.OVH.NET              "In"
}
EOF
 cat > ~/.wl <<EOF
;; SMTP
(setq wl-smtp-connection-type 'starttls)
(setq wl-smtp-posting-port 587)
(setq wl-smtp-authenticate-type "plain")
(setq wl-smtp-posting-user "mickael@kerjean.me")
(setq wl-smtp-posting-server "SSL0.OVH.NET")
(setq wl-local-domain "kerjean.me")
(setq wl-from "mickael@kerjean.me")
 ;; conf
(setq wl-folder-check-async t)
(setq elmo-imap4-use-modified-utf7 t)
(autoload 'wl-user-agent-compose "wl-draft" nil t)
(if (boundp 'mail-user-agent)
  (setq mail-user-agent 'wl-user-agent))
  (if (fboundp 'define-mail-user-agent)
  (define-mail-user-agent
    'wl-user-agent
    'wl-user-agent-compose
    'wl-draft-send
    'wl-draft-kill
    'mail-send-hook))
(autoload 'wl "wl" "Wanderlust" t)
(autoload 'wl-other-frame "wl" "Wanderlust on new frame." t)
(autoload 'wl-draft "wl-draft" "Write draft with Wanderlust." t)
(add-hook 'wl-init-hook (lambda () (linum-mode nil)))
EOF

Reference: the repo

Other Stuff I like

Smooth scroll

The default scroll in emacs feels weird to me. Let’s fix this:

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins
git clone -b 'v2.0.0' --depth 1 --single-branch https://github.com/aspiers/smooth-scrolling

cat > ~/.emacs.d/conf/smooth-scroll.el <<EOF
;; begin(smooth-scroll)
(add-to-list 'load-path "~/.emacs.d/plugins/smooth-scrolling")
(require 'smooth-scrolling)
(setq mouse-wheel-scroll-amount '(1 ((shift) . 1))) ;; one line at a time
(setq mouse-wheel-follow-mouse 't) ;; scroll window under mouse
(setq scroll-step 1)
;; end(smooth-scroll)
EOF

Reference: the repo

Window centered mode

To makes your text centered instead of being stuck on the left side of your window

Install:

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins/
git clone --depth 1 https://github.com/anler/centered-window-mode
cd ./deps
git clone -b '1.11.0' --depth 1 --single-branch https://github.com/magnars/s.el

cat > ~/.emacs.d/conf/window-centered-mode.el <<EOF
;; begin(window-centered-mode)
(add-to-list 'load-path "~/.emacs.d/plugins/centered-window-mode")
(add-to-list 'load-path "~/.emacs.d/plugins/deps/s.el")
(require 'centered-window-mode)
(centered-window-mode t)
;; end(window-centered-mode)
EOF

Reference: the repo

Ace Jump

To quickly jump your cursor to some other position, ace jump is pretty nice:

Install:

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins
git clone -b 'v2.0' --single-branch --depth 1 https://github.com/winterTTr/ace-jump-mode
cat > ~/.emacs.d/conf/ace-jump.el <<EOF
;; begin(ace-jump)
(add-to-list 'load-path "~/.emacs.d/plugins/ace-jump-mode")
(autoload 'ace-jump-mode "ace-jump-mode" "ace jump mode" t)
(define-key global-map (kbd "C-c C-SPC") 'ace-jump-mode)
;; end(ace-jump)
EOF

C-c C-SPC and type the first letter of the location you’re trying to go and let you guide!

Reference: the repo

Powerline

Just to make the status bar looks a bit more fancy:

Install:

mkdir -p ~/.emacs.d/plugins/ && cd ~/.emacs.d/plugins
git clone -b '2.4' --depth 1 --single-branch https://github.com/milkypostman/powerline
cat > ~/.emacs.d/conf/powerline.el <<EOF
;; begin(powerline)
(add-to-list 'load-path "~/.emacs.d/plugins/powerline")
(require 'powerline)
(powerline-default-theme)
;; end(powerline)
EOF

Reference: the repo

Mutliple cursors

Some other features some people like multiple-cursor

Get tabs in emacs Tabbar

I don’t use it anymore as I much prefer projectile and change buffer directly but if you can’t live without tabs, checkout tabbar

What next?

Be aware that’s there’s a lot of other emacs plugins in the market (one of the missing but very well known is helm but because I don’t use it doesn’t mean it isn’t worth looking into it).

This was the fourth episode of this emacs tutorial series and we’re already approaching the end. Until now we’ve been a typical user of emacs without really digging inside emacs internals which is the topic of the last episode.