Hi,
here is my first elisp function 'paren-close-dwim' and I would be glad
to get some feedback on it (whether its done to complicated, in an
unusual way, or whether this functionality is already available in
some emacs extension which I have not found).
The function allows to close braces/brackets/paranthesis without the
user to care which kind of brace actually has to be closed next. For
me this is much handier than using paren-mode or auto-pair etc,
especially when modifying existing code. Automatic paren modes came in
the way and did the wrong thing from time to time for me and I had to
delete automatically inserted closing paranthesis which was hindering
my workflow. So, to be honest, I were not able to master them
appropriately enough with my muscle memory.
I work with a German keyboard layout where braces are not that easily
reachable as on the Englisch layout, but I want to stick with this and
just want to avoid some uncomfortable key-strokes for closing braces.
So, here is my function paren-close-dwim, which you can freely pick
and use for your own configuration. Maybe it is a bit
'over-commented', which only represents my still lacking elisp
fluency.
(defun paren-close-dwim ()
"Insert the next missing closing paranthesis based on the syntax table.
Otherwise insert a normal closing ?\)"
(interactive)
(save-excursion
(setq fallback-char ?\))
;; go backward up a level in the parenthesis hierarchy (which
;; jumps to the next not yet closed (seen from point) open
;; parenthesis). Catch unbalanced paranthesis error etc.
(setq closing-paren
(condition-case nil
(progn (backward-up-list)
;; get character at point
(setq open-paren (point))
;; get corresponding closing character from the
;; syntax table. (syntax-after open-paren)
;; delivers a cons cell with (OPEN . CLOSE), so
;; we need the cdr to match open-paren.
(setq syntax-cons (syntax-after open-paren))
(if (cdr syntax-cons)
(cdr syntax-cons)
;; if cdr is nil use the fallback-char
fallback-char))
(error fallback-char))))
;; insert dwim parenthesis
(insert closing-paren))
;; I bind this to the normal closing paranthesis key and am quite happy
;; with its behaviour in several different modes since a few weeks now.
(global-set-key (kbd ")") 'paren-close-dwim)
Thanks for your feedback,
Florian