[emacs] [emacs lisp] Вопрос по функции add-hook

(defun ret-is-newline-and-indent ()
  "enable automatic indentation"
  (define-key global-map (kbd "RET") 'newline-and-indent))

;;enable automatic indentation
(add-hook 'c-mode-hook 'ret-is-newline-and-indent)
(add-hook 'c++-mode-hook 'ret-is-newline-and-indent)
(add-hook 'scheme-mode-hook 'ret-is-newline-and-indent)

;; disable automatic indentation for haskell-mode 
(add-hook 'haskell-mode-hook 
          '(lambda () 
             (define-key global-map (kbd "RET") 'newline)))

(defun my-ret-hook()
  "Make new lines indented"
  (local-set-key (kbd "RET") 'newline-and-indent))

(dolist (mode '(c-mode-hook c++-mode-hook scheme-mode-hook))
  (add-hook mode 'my-ret-hook))