Add commands to increment and decrement an integer at point

README.md

@@ -232,6 +232,8 @@ Keybinding         | Description
 <kbd>C-c t</kbd> | Open a terminal emulator (`ansi-term`).
 <kbd>C-c k</kbd> | Kill all open buffers except the one you're currently in.
 <kbd>C-c h</kbd> | Open Helm (a useful means of navigating your buffers and project files).
+<kbd>C-c +</kbd> | Increment integer at point.
+<kbd>C-c -</kbd> | Decrement integer at point.
 <kbd>Super-r</kbd> | Recent files
 <kbd>Super-x</kbd> | Expand region
 <kbd>Super-j</kbd> | Join lines

core/prelude-core.el

@@ -453,5 +453,66 @@ Doesn't mess with special buffers."
     (prelude-recompile-init)
     (message "Update finished. Restart Emacs to complete the process.")))
 
+(defun thing-at-point-goto-end-of-integer ()
+  "Go to end of integer at point."
+  (let ((inhibit-changing-match-data t))
+    ;; Skip over optional sign
+    (when (looking-at "[+-]")
+      (forward-char 1))
+    ;; Skip over digits
+    (skip-chars-forward "[[:digit:]]")
+    ;; Check for at least one digit
+    (unless (looking-back "[[:digit:]]")
+      (error "No integer here"))))
+(put 'integer 'beginning-op 'thing-at-point-goto-end-of-integer)
+
+(defun thing-at-point-goto-beginning-of-integer ()
+  "Go to end of integer at point."
+  (let ((inhibit-changing-match-data t))
+    ;; Skip backward over digits
+    (skip-chars-backward "[[:digit:]]")
+    ;; Check for digits and optional sign
+    (unless (looking-at "[+-]?[[:digit:]]")
+      (error "No integer here"))
+    ;; Skip backward over optional sign
+    (when (looking-back "[+-]")
+        (backward-char 1))))
+(put 'integer 'beginning-op 'thing-at-point-goto-beginning-of-integer)
+
+(defun thing-at-point-bounds-of-integer-at-point ()
+  "Get boundaries of integer at point."
+  (save-excursion
+    (let (beg end)
+      (thing-at-point-goto-beginning-of-integer)
+      (setq beg (point))
+      (thing-at-point-goto-end-of-integer)
+      (setq end (point))
+      (cons beg end))))
+(put 'integer 'bounds-of-thing-at-point 'thing-at-point-bounds-of-integer-at-point)
+
+(defun thing-at-point-integer-at-point ()
+  "Get integer at point."
+  (let ((bounds (bounds-of-thing-at-point 'integer)))
+    (string-to-number (buffer-substring (car bounds) (cdr bounds)))))
+(put 'integer 'thing-at-point 'thing-at-point-integer-at-point)
+
+(defun prelude-increment-integer-at-point (&optional inc)
+  "Increment integer at point by one.
+
+With numeric prefix arg INC, increment the integer by INC amount."
+  (interactive "p")
+  (let ((inc (or inc 1))
+        (n (thing-at-point 'integer))
+        (bounds (bounds-of-thing-at-point 'integer)))
+    (delete-region (car bounds) (cdr bounds))
+    (insert (int-to-string (+ n inc)))))
+
+(defun prelude-decrement-integer-at-point (&optional dec)
+  "Decrement integer at point by one.
+
+With numeric prefix arg DEC, decrement the integer by DEC amount."
+  (interactive "p")
+  (prelude-increment-integer-at-point (- (or dec 1))))
+
 (provide 'prelude-core)
 ;;; prelude-core.el ends here

core/prelude-mode.el

@@ -60,6 +60,8 @@
     (define-key map (kbd "C-c k") 'prelude-kill-other-buffers)
     (define-key map (kbd "C-c TAB") 'prelude-indent-rigidly-and-copy-to-clipboard)
     (define-key map (kbd "C-c h") 'helm-prelude)
+    (define-key map (kbd "C-c +") 'prelude-increment-integer-at-point)
+    (define-key map (kbd "C-c -") 'prelude-decrement-integer-at-point)
     ;; make some use of the Super key
     (define-key map [?\s-d] 'projectile-find-dir)
     (define-key map [?\s-p] 'projectile-switch-project)
@@ -99,7 +101,9 @@
                          ["Duplicate line or region" prelude-duplicate-current-line-or-region]
                          ["Indent rigidly and copy to clipboard" prelude-indent-rigidly-and-copy-to-clipboard]
                          ["Insert date" prelude-insert-date]
-                         ["Eval and replace" prelude-eval-and-replace])
+                         ["Eval and replace" prelude-eval-and-replace]
+                         ["Increment integer at point" prelude-increment-integer-at-point]
+                         ["Decrement integer at point" prelude-decrement-integer-at-point])
 
                         ("Navigation"
                          ["Helm" helm-prelude])