A series of notes that I learn Emacs hacking. Change variable globally, disabling auto-save and auto-backup; `require` keyword, enabling recent files opening, enabling delete selection mode; code block and example block fast typing; initializing Emacs with full screen; showing matching parenthesis, highlighting current line; package management system configuration; adding a new theme, hundgry delete mode, swiper, smartparens; customize-group; ordered list in org-mode; JavaScript IDE in Emacs; setting schedule in org-mode.

setq vs. setq-default

• Cursor type is a buffer-local variable. setq will change a local buffer cursor type.
• Use setq-default to change global setting.

Disable auto-save / auto-backup

• (setq make-backup-files nil)

Require

• There are files in the system, use this function to load them, similarly to include or import.
• (require 'org)

Deal with the recent files

• (require 'recentf): activate it.
• (recentf-mode 1)
• (setq recentf-max-menu-items 25)
• (global-set-key "\C-x\ \C-r" 'recentf-open-files): such that we can open recent file by C-x C-r.

Delete the selection words

• (delete-selection-mode t): select some block and type sth, it will change. The previous version do this by append.

shortkey for entering SRC block

• <s and <tab>
• Example block: <e <tab>

start Emacs with full screen

• (setq initial-frame-alist (quote ((fullscreen . maximized))))

Show matched Parenthesis

• (add-hook 'emacs-lisp-mode-hook 'show-paren-mode)

Highlight the current line

• (global-hl-line-mode t)

Configurate the Package Management system

• MELPA: https://melpa.org/#/
• Note: number of download is not neccessarily means it is useful.
• Use the following command to add the package:

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;; Add the package source
(when (>= emacs-major-version 24)
  (require 'package)
  (package-initialize)
  (add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/") t)
  )

(require 'cl)
;; Add whatever packages you want here
(defvar LanternD/packages '(
			    company
			    monokai-theme
			    ) "Default packages")

(defun LanternD/packages-installed-p ()
  (loop for pkg in LanternD/packages
	when(not (package-installed-p pkg)) do (return nil)
	finally (return t)))

(unless (LanternD/packages-installed-p)
  (message "%s" "Refreshing package database...")
  (package-refresh-contents)
  (dolist (pkg LanternD/packages))
  (when (not (package-installed-p pkg))
    (package-install pkg))
  )

• If the above is not working, go to Melpa’s home page to find instruction.

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(require 'package) ;; You might already have this line
(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
		    (not (gnutls-available-p))))
       (url (concat (if no-ssl "http" "https") "://melpa.org/packages/")))
  (add-to-list 'package-archives (cons "melpa" url) t))
(when (< emacs-major-version 24)
  ;; For important compatibility libraries like cl-lib
  (add-to-list 'package-archives '("gnu" . "http://elpa.gnu.org/packages/")))
(package-initialize) ;; You might already have this line

• We can now add package from the Package management system.

Add a new theme

• Go to Package Management, install “monokai-theme”
• M-x load <enter> monokai <enter>, done.

Install hungry-delete-mode

• Delete similar stuff all at once!

Package management advanced

• M-x package-list-packages <enter>: this is equivalent to open the package management system in the menu.
• Press <i>, <d>, <u> to mark “Install”, “Delete” and “Upgrade” to the packages.
• After marking a package, press <x> to confirm.
• <U>: captical U to execute global upgrade to all installed packages.
• If too many packages are installed, be CAUTIOUS to upgrade all packages at once. Something terrible may happen.
• M-x package-autoremove: Auto remove packages.

About smex package

• An augmented M-x.
• after key-binding, press M-x, use C-s to navigate in the command available.

About swiper package

• type in the stuff
• Use C-n, C-p to navigate
• C-x C-f now can navigate like a folder access.

About smartparens package

• Help you type in the right parenthensis after you enter the left one.
• Remember to add hook to certain major mode.

Customize group

• M-x customize-group, then type in the name, then we can enter the configuration for each package.
• M-x customize-option: a more detailed option list.

Tips on order list in org-mode

• M-<return> can help to reorder the list, so that the numbers are current.

  ()

  1. ss
  2. r234
  3. 553233
  4. 443saf
  5. asdjio

Be careful, M-<return> will match the previous format.

About JavaScript IDE

• By default, Emacs open js with the JavaScript major mode.
• Suppose we already have js2-mode installed, we can switch to that.
• Install js2-mode for the IDE.

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(setq auto-mode-alist
  (append
    '(("\\.js\\'" . js2-mode))
      auto-mode-alist))

• Install nodejs-repl, which is for executing the .js file. (require node.js installed in the system).
• M-x nodejs-repl-send-buffer: execute this command in the .js file. Then the file will be executed in the frame.

TODO Reading recommendation

• M-x Info: open Info.
• C-h i: same as above.
• Read “Emacs Lisp Intro” (“Introduction to Emacs Lisp Programming”), especially the section of loop and recursion.

Use org to set schedule

• Create a “gtd.org” file

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(setq org-agenda-files '("~/org"))
(global-set-key (kbd "C-c a") 'org-agenda)

• Bind a key to open the .org file.
• C-c C-s: set a scheduled time.
• C-c C-d: set the deadline time.