How to complete brackets automatically?

Question

I use an auto complete tool in emacs, which can complete brackets. But I want to find out that how it determines whether it should complete the bracket. For example, assuming | stands for the point. In the case of | abc, when typing (, it will auto complete to (|) abc. In another case of |abc , when typing (, it will not auto complete just like what sublime does.

Answer 1

Add this line to your emacs init file

(setq electric-pair-preserve-balance nil)

Reference: https://stackoverflow.com/questions/27142996/electric-pair-mode-dont-pair-if-cursor-precedes-a-non-whitespace-character

Answer 2

A possible way to do that:

(defun jp/insert-parentheses ()
"Insert a pair of parenthesis if next char is space or newline, or end of buffer"
  (interactive)
  (let ((c (char-after (point))))
    (cond
     ((or (not c) (= c 32) (= c 10)) (insert "()"))
     (t (insert "(")))))


(global-set-key "(" #'jp/insert-parentheses)

Where 32 is the code for a space character and 10 for newline. The not thing is for when point is at end of buffer (char-after will return nil, and we want to allow insertion of a pair of parenthesis in this case).

Answer 3

The possible solution for this question I found is: 1) exclude the smartparens for it haven't support such a function.

dotspacemacs-excluded-packages '(smartparens)

2) add electric package when init

(electric-pair-mode 1)
(setq electric-pair-preserve-balance nil)