Is there a better way of writing this with use-package?

Question

I feel like there is a better way of writing this with use-package but I just can't get the usual way to work.

(use-package eshell
  :hook
  (eshell-mode
   . (lambda ()
       (define-key
         eshell-mode-map
         (kbd "C-<backspace>")
         (lambda () ; clear shell
           (interactive)
           (message "I am some other function"))))))

I tried using the :bind (:map eshell-mode-map ("C-<backspace>" . <lambda here>)), but that just binds the function to the global key map for some reason. Maybe because eshell-mode-map is nil till eshell is launched. Could someone suggest a better utilisation of use-package to write what I already have?

Answer 1

The keybindings created with :bind expect a function name (not sure how lambdas are expanded) so you can define a named function in the :init clause of use-package which should work as expected...

(use-package eshell
  :after esh-mode
  :init 
  (defun my-clear-shell ()
    (interactive)
    (message "I am some other function"))
  :bind (:map 
     eshell-mode-map
     ("C-<backspace>" . my-clear-shell)))

Answer 2

Rewrite your config to keep it simple:

(defun your-eshell-clear ()
  (interactive)
  (message "TODO impl your-eshell-clear"))

(defun your-eshell-setup ()
  (define-key eshell-mode-map (kbd "C-<backspace>") #'your-eshell-clear))

(add-hook 'eshell-mode-hook #'your-eshell-setup)

You can simplly put it to your init file, it will not slow your Emacs startup. If you need, you can group it via progn or with-eval-after-load or use-package, thought they does not provide actual benefits, and use-package sometimes can make your init file more complex and harder to understand.