Create æ-enclose-region and bind it to M-(

It encloses region in the specified character, or pair of brackets.

init.el

@@ -117,6 +117,7 @@
 (load "zim.el")
 (load "clearcase.el")
 (load "jekyll.el")
+(load "enclose-string.el")
 
 (add-hook 'c-mode-hook
           (lambda ()
@@ -359,3 +360,5 @@ Version 2016-02-16"
 (add-hook 'org-mode-hook
           (lambda ()
             (if (display-graphic-p) (org-bullets-mode t))))
+
+(global-set-key (kbd "M-(") 'æ-enclose-region)

lisp/enclose-string.el

@@ -0,0 +1,34 @@
+(defun æ-enclose-region (character &optional start end)
+  "Enclose region in CHARACTER. If region is empty, simply inserts
+  CHARACTER two times and moves point between them.
+
+  If character is present in `insert-pair-alist', this function
+  will enclose region in the corresponding pair. In this case,
+  CHARACTER must be the opening member of the pair."
+
+  (interactive "cWhat character? \nr")
+
+  (setq open character close character)
+
+  (let ((pair (assq character insert-pair-alist)))
+    (if pair
+        (if (nth 2 pair)
+            (setq open (nth 1 pair) close (nth 2 pair))
+          (setq open (nth 0 pair) close (nth 1 pair)))))
+
+  (unless (and open close)
+    (setq open character)
+    (setq close character))
+
+  (unless (use-region-p)
+    (setq start (point) end (point)))
+
+  (save-excursion
+    (goto-char end)
+    (insert-char close)
+
+    (goto-char start)
+    (insert-char open))
+
+  (unless (use-region-p)
+      (forward-char)))