Emacs: mark and register basics

2023-06-28

Raw link: https://www.youtube.com/watch?v=TJrAkCyH6Dk

Video overview on how to use the mark and registers in Emacs to select or edit text efficiently, as well as to quickly jump to points of interest across files/buffers. I also mention bookmarks, which are functionally the same as registers.

Some basic configurations:

;; Make Emacs repeat the C-u C-SPC command (`set-mark-command') by
;; following it up with another C-SPC.  It is faster to type
;; C-u C-SPC, C-SPC, C-SPC, than C-u C-SPC, C-u C-SPC, C-u C-SPC...
(setq set-mark-command-repeat-pop t)

;; By default, the built-in `savehist-mode' only keeps a record of
;; minibuffer histories.  This is helpful as it surfaces the most
;; recently selected items to the top, allowing you to access them again
;; very quickly.  With the variable `savehist-additional-variables' we
;; can make `savehist-mode' keep a record of any variable we want, so
;; that it persists between Emacs sessions.  I do this to store the
;; `kill-ring' and the `register-alist'.
(setq savehist-additional-variables '(register-alist kill-ring))

(savehist-mode 1)

;; I want Emacs to write the list of bookmarks to the `bookmark-file'
;; as soon as I set a new bookmark.  The default behaviour of Emacs is
;; to write to the disk as a final step before closing Emacs.  Though
;; this can lead to data loss, such as in the case of a power failure.
;; Storing the data outright mitigates this problem.
(defun prot/bookmark-save-no-prompt (&rest _)
  "Run `bookmark-save' without prompts.

The intent of this function is to be added as an :after advice to
`bookmark-set-internal'.  Concretely, this means that when
`bookmark-set-internal' is called, this function is called right
afterwards.  We set this up because there is no hook after
setting a bookmark and we want to automatically save bookmarks at
that point."
  (funcall 'bookmark-save))

(advice-add 'bookmark-set-internal :after 'prot/bookmark-save-no-prompt)

;; After publishing the above, I learnt about this variable, which has
;; the same effect as `prot/bookmark-save-no-prompt':
(setq bookmark-save-flag 1)

;; If you are using the wonderful `consult' package, set up the
;; register preview facility with its more informative presentation:
(setq register-preview-delay 0.8
      register-preview-function #'consult-register-format)

UPDATE 2023-06-30 22:33 +0300: Add two more snippets to the code block.