Why Use Emacs and Tips

About Emacs

Sources:

• Beginners Guide to Emacs - technical introduction
• Absolute Beginners Guide to Emacs with pictures and key bindings, good plain language overview

Tagline: Emacs is the extensible, customizable, self-documenting real-time display editor.

Emacs is:

• a tiling window manager

Terms

• Buffer: where you read/write text, can be a shell, file, snippets, email, etc.
• Frames and windows:
  • Frame can be open, closed, minimized, maximized, and dragged around
  • Window is bit of the frame that displays a buffer. There can be unlimited windows in a frame
• Modeline, Echo area, Minibuffer
  • Echo area: void at bottom of emacs and is only ever one. Used to display messages.
  • Mode line: each window has its own mode line with information about the buffer in the that window
  • Minibufer and echo share space: when emacs prompts for action, you are asked to answer in a minibuffer (a small buffer)
• Command and Function
  • Command is an interactive function. Not all functions are commands. Command is something you can interact with in M-x. Commands are sometimes bound to one or more key bindings.
• Major and Minor Modes
  • A major mode imbues a buffer with the capabilities it needs to do a particular job (e.g. open a .c file or an .org file to activate that mode for the file).
    • You can only have one major mode active in a buffer at a time.
    • Unlimited minor modes can be active at the same time.
• Point and Mark
  • Point = cursor caret.
  • Mark is a transient beacon (selection rectangle) that is on the other region of the point.
  • Together they form the region
• Killing and Yanking
  • Emacs clipboard is the kill ring.
  • Killing (cut) text appends to the same clipboard entry if you successively kill text. The clipboard entry the text goes into is only broken when you break the chain of kill commands by using a key binding or command that does not kill text.
    • e.g. calling M-d (delete forward word) 3 times creates a kill ring entry with the three words
  • Yanking (paste) text can recall the end of the ring and previously killed items using C-y with M-y to cycle through the ring.
  • Kill ring entries can be limited to set emacs to discard entries.
• Undoing
  • Undo works like the kill ring and undo actions can be redone.
• Movement and Editing
  • Arrow keys can be used
  • Emacs also has its own keys

Asking Emacs Help

• Use C-h r, which is also bound to M-x info or Help -> Read the Emacs Manual in the menu bar. Also use Help -> Search Documentation.
• Ask about a specific key to know what is does: C-h k (or Help -> Describe -> Describe Key or Mouse Operation). It is contextual so run it for the buffer you intend to run the command.
• If you know the name of the function or command, use:
  • C-h f (or Help -> Describe -> Describe Function)
  • You’re then treated to a documentation string of the function along with any keys it’s bound to.
  • You can press i (Emacs 28+) to open the corresponding manual page, if any, for that function.
  • The manual is usually more detailed and includes similar functions
• Check active modes in the current buffer:
  • C-h m (or Help -> Describe -> Describe Buffer Modes)

Customizing Emacs

• You can customize Emacs with elisp or with the builtin Customize interface. Customize is recommended for beginners.
• Applying One-off Changes
  • One example is M-x fido-mode or ido-mode an intelligent search-as-you-type framework. If you were to just type it into M-x then it’ll work great until you exit Emacs. At that point it, or indeed any other change you’ve made but haven’t explicitly saved, is lost.
  • How do you fix that? You can add it to your init.el file in ~/.emacs.d/init.el or you can check and see if it’s supported by the customize interface: M-x customize-option RET fido-mode RET.

Why Learn Emacs?

Source: Why use emacs in 2021

Top Reasons

• Productivity environment you can customize with Lisp
• Manage projects, tasks, and appointments with org mode
• Manage email (mu4e), IRC/Telegram/Facebook/etc. chats (ERC, telega.el) with packages
• Management remote servers with TRAMP
• Full desktop environment with Emacs X Window Manager (EXWM) - only on Linux

and:

• Vim style editing with evil mode
• IDE capabilities with lsp-mode and dap-mode
• Magit git client: GUI and one button commands
• Integration with compilers, test runners, linters, debuggers, etc.

Keyboard driven interface

• Specific Bindings for modes
• Create your own bindings that are bound to prefixes (use a leader key like C-SPC)
• Enable transient keymaps (set-transient-map)

Discoverable

• Use describe-bindings or which-key to know keys
• Use describe-key to know what a key does

Crafting Environment

• UI is open to customization, see Emacs from scratch - customization of UI
• Customize behaviour:
  • Hook - a function that is called when a certain event occurs
  • Advice - a function that is called before or after another function

Power of Org Mode

• Todo lists, writing notes and logs
• Literate programming - run code blocks and have results in buffer; like Jupyter notebook
• Spreadsheets
  • Calculations
• System configuration
  • System configuration through org-babel
  • Blocks can export output to file system configuration files

Tips

• Use M-x menu-bar-mode to enable the menu bar temporarily
• Use the mouse and menu bar for contextual help, links, and bottom bar options
• View packages M-x list-packages or selecting it from Options -> Manage Emacs Packages
  • Update packages: run list-packages hit U to mark available upgrades, then review to decide if there are any not required. Then x to upgrade
• M (alt) is used for operations related to units of the language (words, sentences). While C (Control) operates on basic units like characters and lines