22.13 Remapping Commands

A special kind of key binding, using a special “key sequence” which includes a command name, has the effect of remapping that command into another. Here's how it works. You make a key binding for a key sequence that starts with the dummy event remap, followed by the command name you want to remap. Specify the remapped definition as the definition in this binding. The remapped definition is usually a command name, but it can be any valid definition for a key binding.

Here's an example. Suppose that My mode uses special commands my-kill-line and my-kill-word, which should be invoked instead of kill-line and kill-word. It can establish this by making these two command-remapping bindings in its keymap:

     (define-key my-mode-map [remap kill-line] 'my-kill-line)
     (define-key my-mode-map [remap kill-word] 'my-kill-word)

Whenever my-mode-map is an active keymap, if the user types C-k, Emacs will find the standard global binding of kill-line (assuming nobody has changed it). But my-mode-map remaps kill-line to my-kill-line, so instead of running kill-line, Emacs runs my-kill-line.

Remapping only works through a single level. In other words,

     (define-key my-mode-map [remap kill-line] 'my-kill-line)
     (define-key my-mode-map [remap my-kill-line] 'my-other-kill-line)

does not have the effect of remapping kill-line into my-other-kill-line. If an ordinary key binding specifies kill-line, this keymap will remap it to my-kill-line; if an ordinary binding specifies my-kill-line, this keymap will remap it to my-other-kill-line.