[elisp] easy-to-use bookmarks functionality

[alex_sv <avshabanov@gmail.com>]

Hi all,

For my own needs I wrote a small function that provides easy-to-use
bookmarking: C-[1..9] - sets "bookmark" (in fact remembers point in
the corresponding register), M-[1..9] - jumps to the corresponding
position.

Now I would like to see whether it could be implemented in a less
verbose and more intelligent way.

The flaws of my function are:
1) I don't know how to construct "key sequence" object from the
strings part, e.g. get "\C-1" sequence from the source strings "C-"
and "1", so I wrote local helper function - get-key-code that accepts
key sequence strings and creates the corresponding key sequence using
eval form with a call to kbd.
2) local-set-key function can't use locally defined closures so I
constructed corresponding lambda using append/list/quote facility that
looks quite ugly.

Here is the function:

(defun bind-navigation-command-to-numkeys ()
  "provides easy-to-use bookmarking functionality - binds navigation
commands to
C-{index}, M-{index} keys, where index is a numeric key from 1 to 9"
  (let (
	;; helper function that returns key sequence object that
	;; corresponds to the concatenated string sequence given
	(get-key-code (lambda (&rest key-sequence-str-list)
			(eval (let ((key-sequence
				     (mapconcat
				      (function
				       (lambda (c) c))
				      key-sequence-str-list "")))
				(append (list 'kbd)
					(list key-sequence)))))))
    ;; assign handlers for C/M-[1..9] keys
    (loop for key-index from 1 to 9 do
	  (let ((key-str (int-to-string key-index)))
	    ;; save point
	    (local-set-key (funcall get-key-code "C-" key-str)
			   ;; handler form
			   (list 'lambda '()
				 '(interactive)
				 (list 'point-to-register key-index)))
	    ;; goto saved point
	    (local-set-key (funcall get-key-code "M-" key-str)
			   ;; handler form
			   (list 'lambda '()
				 '(interactive)
				 (list 'register-to-point key-index)))))))

comments appreciated :)