suppress additional braces in emacs electric mode

Question

Hi,

I started using ruby-electric-mode. I like it except that I am used to closing open brackets myself (the other pairing are still useful to me). How can I make emacs suppress additional brackets when I type in the closing brackets myself? I now am manually deleting the auto-magically inserted bracket every time.

Thanks in advance, Raghu.

Answer 1

It is a “customizable” setting. Run M-x customize-variable (ESCx if you do not have a Meta key) and customize ruby-electric-expand-delimiters-list.

Uncheck “Everything” and check only the ones you want to be automatically inserted. Be sure to also “Save for Future Sessions”.

If you decide that you mostly like the automatic insertions but that there are some places where you want to turn it off for a single keystroke, then use C-q (Control-q) before an open paren/bracket/brace/quote to suppress the automatic insertion of the closing mark.

Answer 2

It sounds like what you want is for the } to either jump to the (already inserted) }, or to simply insert a } and delete the } that was inserted earlier by the electric mode.

This code should do what you want, the choice of what to do on } is toggled by the variable my-ruby-close-brace-goto-close.

;; assuming
;; (require 'ruby)
;; (require 'ruby-electric)
(defvar my-ruby-close-brace-goto-close t
  "Non-nill indicates to move point to the next }, otherwise insert } 
and delete the following }.")

(defun my-ruby-close-brace ()
  "replacement for ruby-electric-brace for the close brace"
  (interactive)
  (let ((p (point)))
    (if my-ruby-close-brace-goto-close
        (unless (search-forward "}" nil t)
          (message "No close brace found")
          (insert "}"))
      (insert "}")
      (save-excursion (if (search-forward "}" nil t)
                           (delete-char -1))))))
(define-key ruby-mode-map "}" 'my-ruby-close-brace)