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How do I add / remove parentheses around a marked area in Emacs?

I often find it necessary to add / remove parentheses / brackets around the marked area in Emacs.

I am currently adding manually:

  • Move the cursor to one end of the intended area, enter the opening separator;
  • Move the cursor to the other end of the intended area, enter the final separator;

And removal in another way.

However, this seems cumbersome and error prone due to cursor movement. From a security point of view, if I remove the parentheses in pairs, I feel safer because it is an atomic operation

Is there a built-in or hand-crafted function in Emacs to do this in relation to the marked area?

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3 answers


  • Removing pairs surrounding characters (parens, brackets, whatever) around sexp: C-M-u M-x delete-pair

    .
  • Adding an area using parsers: area designation and M-(

    .


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Try the following functions:

(defun surround-with-parens ()
  (interactive)
  (save-excursion
    (goto-char (region-beginning))
    (insert "("))
  (goto-char (region-end))
  (insert ")"))

(defun delete-surrounded-parens ()
  (interactive)
  (let ((beginning (region-beginning))
        (end (region-end)))
    (cond ((not (eq (char-after beginning) ?\())
           (error "Character at region-begin is not an open-parenthesis"))
          ((not (eq (char-before end) ?\)))
           (error "Character at region-end is not a close-parenthesis"))
          ((save-excursion
             (goto-char beginning)
             (forward-sexp)
             (not (eq (point) end)))
           (error "Those parentheses are not matched"))
          (t (save-excursion
               (goto-char end)
               (delete-backward-char 1)
               (goto-char beginning)
               (delete-char 1))))))

The first inserts parentheses around the region, leaving point after the closing parenthesis. The latter only removes the parentheses if they are exactly * surrounded by the scope, and if they match correctly.

For example, it will refuse to remove those parentheses:



(x a b c d (y) z)
^            ^
this         and this

* This can be improved by looking inward for parentheses rather than being on the exact region boundaries; I will do this later if I have time.

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try this:

(global-set-key "\M-'" 'insert-quotations)
(global-set-key "\M-\"" 'insert-quotes)
(global-set-key (kbd "C-'") 'insert-backquote)

(defun insert-quotations (&optional arg)
  "Enclose following ARG sexps in quotation marks.
Leave point after open-paren."
  (interactive "*P")
  (insert-pair arg ?\' ?\'))

(defun insert-quotes (&optional arg)
  "Enclose following ARG sexps in quotes.
Leave point after open-quote."
  (interactive "*P")
  (insert-pair arg ?\" ?\"))

(defun insert-backquote (&optional arg)
  "Enclose following ARG sexps in quotations with backquote.
Leave point after open-quotation."
  (interactive "*P")
  (insert-pair arg ?\` ?\'))

https://www.emacswiki.org/emacs/InsertPair

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