insert symbol instead of numeral

insert-symbol.el

;;;; 2014-01-12
;;;; 数字キーを押した時に数字じゃなく記号が出るようになるelisp 
;; キーボード最上段を押下時　!@#$%^&*()-=\` が出力されます
;; SHIFT押しながらだと　　　 1234567890_+|~ が出力されます

;; US配列
(defvar alternate-chars
  '(("1" "!")
    ("2" "@")
    ("3" "#")
    ("4" "$")
    ("5" "%")
    ("6" "^")
    ("7" "&")
    ("8" "*")
    ("9" "(")
    ("0" ")")))
(defvar insert-symbol-mode-map (make-sparse-keymap))

(defun convert-to-keymap (lst)
  (mapcan (lambda (clause)
            `((,(first clause) . (lambda () (interactive) (insert ,(second clause))))
              (,(second clause) . (lambda () (interactive) (insert ,(first clause))))))
          lst))

(defun update-insert-symbol-mode-map ()
  (setq insert-symbol-mode-map (make-sparse-keymap))
  (mapcar (lambda (x)
            (eval `(define-key insert-symbol-mode-map (kbd ,(first x)) (rest x))))
          (convert-to-keymap alternate-chars)))

(update-insert-symbol-mode-map)
(easy-mmode-define-minor-mode
 insert-symbol-mode
 "Insert symbol instead of numeral"
 t "insert-symbol" insert-symbol-mode-map)

;; C-M-gで有効無効の切り替え
(global-set-key (kbd "C-M-g") 'insert-symbol-mode)