Add commands to work with numbers

1 files changed, 28 insertions, 0 deletions

diff --git a/.emacs.d/init.org b/.emacs.d/init.org
index 36e9983..28b8cf9 100644
--- a/.emacs.d/init.org
+++ b/.emacs.d/init.org
@@ -467,3 +467,31 @@
     (autoload 'moz-minor-mode "moz" nil t)
     (add-hook 'javascript-mode-hook 'moz-minor-mode)
   #+END_SRC
+
+* Change numbers at point
+
+  Sometimes you just want to increase or decrease the number under the
+  cursor, no fuss.
+
+  #+BEGIN_SRC emacs-lisp
+    (defun change-number-at-point (change-func)
+      "Use CHANGE-FUNC to change the number at `point'."
+      (let ((num (number-to-string (funcall change-func (number-at-point))))
+            (bounds (bounds-of-thing-at-point 'word)))
+        (save-excursion
+          (delete-region (car bounds) (cdr bounds))
+          (insert num))))
+
+    (defun decrease-number-at-point ()
+      "Take the number at `point' and replace it with it decreased by 1."
+      (interactive)
+      (change-number-at-point #'1-))
+
+    (defun increase-number-at-point ()
+      "Take the number at `point' and replace it with it increased by 1."
+      (interactive)
+      (change-number-at-point #'1+))
+
+    (global-set-key (kbd "C-c -") #'decrease-number-at-point)
+    (global-set-key (kbd "C-c +") #'increase-number-at-point)
+  #+END_SRC