A series of notes that I learn Emacs hacking. Package loading mechanism, auto-indentation, hippie-expand, dired-mode, basic about org-mode.

Spacemacs Rocks Note Day 4

More about require and load-file

• More accurate exaplaination: If require can not find a feature, Emacs will load that file.
• Priority: require ->= load ->= load-file.
• Load first time: compile and load the .el file; load second time, it will load the corresponding .elc file.
• If there is no “load-path” variable, we must specify whether .el or .elc to be loaded (absolute path).
• byte-compile-file: generate .elc from .el.
• .elc can be executed fasted than .el.
• After executing (provide), the file will be added to feature-list.
• autoload: kind of complicated. Find something on the web if interested.

Indent

• C-M-\: auto indent. This method require file selection.
• Use another function snippet to help us to do the indent job.

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(defun indent-whole-buffer()
  (interactive)
  (indent-region (point-min) (point-max))
  )

(defun indent-region-or-buffer()
  (interactive)
  (save-excursion 
    (if (region-active-p)
    (progn
      (indent-region (region-begin) (region-end))
      (message "Selected region is indented.")
     )
      (progn 
	(indent-whole-buffer)
	(message "The whole buffer is indented.")
       )
      )
    )
  )

(global-set-key (kbd "C-M-\\") 'indent-region-or-buffer)

More about auto-complete - hippie-expand

• company-mode somethimes doesn’t work.
  • For example, type a path without quote mark: ~/.emacs.
  • ”~/.emacs.d/lisp/custom.el”.
• use hippie-expand to deal with these cases.
• Use the following snippet to augment the auto-complete function:

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;; set the list for hippie-expand
(setq hippie-expand-try-functions-list '(try-expand-dabbrev
					 try-expand-dabbrev-all-buffers
					 try-expand-dabbrev-from-kill
					 try-complete-file-name-partially
					 try-complete-file-name
					 try-expand-all-abbrevs
					 try-expand-list
					 try-expand-line
					 try-complete-lisp-symbol-partially
					 try-complete-list-symbol))
(global-set-key (kbd "M-/") 'hippie-expand) ;; this is the default key set

About dired-mode

• Short for “directory edit”
• key <+>: create a folder.
• Then C-x C-f create new file.
• <g>: to refresh the Dired buffer.
• <C>: capital C to copy folder or file.
• <D>: capital D to delete a file or folder.
• <d>: mark the file to delete status.
• <u>: unmark current file status (delete or sth else).
• <x>: execute the marker.
• <R>: rename a file or directory
• Use the following key to limit the dired buffers to only one.

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;; (require 'dired)
(with-eval-after-load 'dired)
(put 'dired-find-alternate-file 'disabled nil)
(define-key dired-mode-map (kbd "RET") 'dired-find-alternate-file)

• with-eval-after-load: load something after everything is loaded, which improves the loading speed of Emacs.
• C-x C-j: open the directory of the current editting file (require 'dired-x).
• (setq dired-dwim-target t): optimize the copy destination dir path.

Save-excursion

• Save the position of the current cursor.

Use org-mode to organize the initialization files

• Use the following snippet:

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(require 'org-install)
(require 'ob-tangle)
(org-babel-load-file (expand-file-name "lanternd_int.org" user-emacs-directory))

• It will generate an .el file, which is equivalent to the init-xxx.el.