Xah Talk Show 2025-09-06 Ep698 Emacs Lisp defvar-keymap

Video Summary (AI Generated)

• This video focuses on Emacs Lisp coding, specifically discussing the new define-keymap and define-var-keymap functions introduced in Emacs 29, which are designed to replace older key binding commands like define-key and global-set-key (3:43, 4:04).

• The creator demonstrates how to use these new functions to define keyboard shortcuts in Emacs, explaining their superiority and the gradual transition developers are making to adopt them (4:53, 6:25, 7:04).
• The video also touches on the practical application of key bindings within custom Emacs Lisp packages, using a CSS mode as an example (10:50, 13:03).
• A significant portion of the video involves the creator attempting to understand and implement these new functions by examining documentation and existing Emacs Lisp source code, highlighting the complexities and occasional inconsistencies in the documentation, especially concerning keyword arguments (18:48, 43:41).

• GNU Pepe

• define-keymap
• defvar-keymap

• Emacs Keys

• Emacs Keys: Define Key

• Emacs Keys: Keybinding Functions, Emacs 29 Change

• Emacs: One Thousand Default Keybinding

• Emacs: Xah Fly Keys 📦

• Visual CSS

;; define-keymap
;; defvar-keymap

(defvar-keymap VARIABLE-NAME &key DOC FULL PARENT SUPPRESS NAME PREFIX
KEYMAP REPEAT &rest [KEY DEFINITION]...)

(defvar-keymap image-map
  :doc "Map put into text properties on images."
  :parent image-slice-map
  "i" (define-keymap
        "r" #'image-rotate
        "h" #'image-flip-horizontally
        "v" #'image-flip-vertically))

(defvar-keymap xah-css-leader-map
  :doc "leader key map"
  :parent xah-css-mode-map
  "TAB" (define-keymap
   "SPC" #'xah-css-complete-symbol
   "f" #'xah-css-format-buffer
   "r" #'xah-css-insert-random-color-hsl
   "x" #'xah-css-hex-color-to-hsl
))