dotfiles/modules/evil.org

#+TITLE: Evil
#+AUTHOR: Christopher James Hayward
#+EMAIL: chris@chrishayward.xyz

#+PROPERTY: header-args:emacs-lisp :tangle evil.el :comments org
#+PROPERTY: header-args            :results silent :eval no-export :comments org

#+OPTIONS: num:nil toc:nil todo:nil tasks:nil tags:nil
#+OPTIONS: skip:nil author:nil email:nil creator:nil timestamp:nil

Transform Emacs into Vim.

* Config

Emacs has some strange default keybindings, which given the age of the project, is not surprising. To overcome this nearly show-stopping hurdle, we transform Emacs into Vim with ~evil~[fn:1], the Extensible VI Layer for Emacs.

#+begin_src emacs-lisp
(use-package evil
  :custom (evil-want-integration t)  ;; Required for `evil-collection'.
          (evil-want-keybinding nil) ;; Same as above
  :config (evil-mode +1))
#+end_src

** Improvements

While covering substantial ground towards the goal, the default keybindings implemented in ~evil~[fn:1] alone are lacking compared to what you would expect from Vim. There's a community curated package ~evil-collection~[fn:2] that does a much better job implementing the proper keybindings.

#+begin_src emacs-lisp
(use-package evil-collection
  :after evil
  :config (evil-collection-init))
#+end_src

** Surround text

Quickly and efficiently surround text with ~evil-surround~[fn:3]. Highlight blocks of text with function definitions, quotations, or any symbol you can input from your keyboard.

#+begin_src emacs-lisp
(use-package evil-surround
  :after evil
  :config (global-evil-surround-mode 1))
#+end_src

** Line numbering

Relative line numbers are important when using VI emulation keys. You can prefix commands with a number, allowing you to perform that action that number of times. Useful when navigating around pages that are hundreds, or even thousands of lines long.

#+begin_example
  5:
  4:
  3:
  2:
  1:
156: << CURRENT LINE >>
  1:
  2:
  3:
  4:
  5:
#+end_example

This behaviour is implemented with ~linum-relative~[fn:4], hooking into the ~display-line-number-mode~ as the backend for good performance in the GUI or TTY.

#+begin_src emacs-lisp
(use-package linum-relative
  :commands (linum-relative-global-mode)
  :custom (linum-delay t)
          (linum-relative-backend 'display-line-numbers-mode))
#+end_src

** Toggle comments

Toggle comments in a language agnostic manner with ~evil-nerd-commenter~[fn:5]. Add a custom binding to =M-;= to mimmic the behaviour in other popular Emacs configuration frameworks. What is =M-?= Called the *Meta* key in Emacs, it typically refers to =Alt=.

#+begin_src emacs-lisp
(use-package evil-nerd-commenter
  :after evil
  :bind ("M-;" . evilnc-comment-or-uncomment-lines))
#+end_src

* Shortcuts

Toggle relative line numbers with =SPC t l=.

#+begin_src emacs-lisp
(dotfiles/leader
  "tl" '(linum-relative-global-mode :which-key "Lines"))
#+end_src

* Footnotes

[fn:1] https://github.com/emacs-evil/evil-mode

[fn:2] https://github.com/emacs-evil/evil-collection

[fn:3] https://github.com/emacs-evil/evil-surround

[fn:4] https://github.com/emacsmirror/linum-relative

[fn:5] https://github.com/redguardtoo/evil-nerd-commenter