1 files changed, 132 insertions, 0 deletions
diff --git a/.config/emacs/site-lisp/increment.el b/.config/emacs/site-lisp/increment.el
new file mode 100644
index 0000000..b5bea53
--- /dev/null
+++ b/.config/emacs/site-lisp/increment.el
@@ -0,0 +1,132 @@
+;;; increment.el -- Increment numbers at point  -*- lexical-binding: t; -*-
+
+(require 'cl-macs)
+(require 'rx)
+
+(defvar increment--binary-number-regexp
+  (rx (group (or ?- word-start))
+      "0b"
+      (group (* ?0))
+      (group (+ (any "01")))
+      word-end))
+
+(defvar increment--octal-number-regexp
+  (rx (group (or ?- word-start))
+      "0o"
+      (group (* ?0))
+      (group (+ (any "0-7")))
+      word-end))
+
+(defvar increment--decimal-number-regexp
+  (rx (group (? ?-))
+      (group (* ?0))
+      (group (+ (any digit)))))
+
+(defvar increment--hexadecimal-number-regexp
+  (rx (group (or ?- word-start))
+      "0x"
+      (group (* ?0))
+      (group (+ (any hex-digit)))
+      word-end))
+
+(defvar increment--hexadecimal-lower-number-regexp
+  (rx (group (or ?- word-start))
+      "0o"
+      (group (* ?0))
+      (group (+ (any "0-9a-f")))
+      word-end))
+
+(defvar increment--number-regexp
+  (rx (or (seq (or ?- word-start)
+               (or (seq "0b" (+ (any "01")))
+                   (seq "0o" (+ (any "0-7")))
+                   (seq "0x" (+ (any hex-digit))))
+               word-end)
+          (seq (? ?-) (+ (any digit))))))
+
+(defun increment--number-to-binary-string (number)
+  (nreverse
+   (cl-loop for x = number then (ash x -1)
+            while (not (= x 0))
+            concat (if (= 0 (logand x 1)) "0" "1"))))
+
+(defun increment--format-number-with-base
+    (number base leading-zeros buffer-substr hex-style)
+  (let* ((neg (> 0 number))
+         (number (abs number))
+         (number-string
+          (pcase base
+            (2  (increment--number-to-binary-string number))
+            (8  (format "%o" number))
+            (10 (number-to-string number))
+            (16 (format (if (eq hex-style 'lower) "%x" "%X") number))))
+         (length-diff (- (length buffer-substr)
+                         (length number-string)))
+         (leading-zeros (if (> leading-zeros 0)
+                            (+ leading-zeros length-diff)
+                          0)))
+    (concat
+     (when neg
+       "-")
+     (pcase base
+       (2 "0b")
+       (8 "0o")
+       (16 "0x"))
+     (when (> leading-zeros 0)
+       (make-string leading-zeros ?0))
+     number-string)))
+
+(defun increment--match-number-at-point ()
+  (cond ((thing-at-point-looking-at
+          increment--binary-number-regexp)
+         (cons 2 nil))
+        ((thing-at-point-looking-at
+          increment--octal-number-regexp)
+         (cons 8 nil))
+        ((thing-at-point-looking-at
+          increment--hexadecimal-number-regexp)
+         (cons 16 nil))
+        ((thing-at-point-looking-at
+          increment--hexadecimal-lower-number-regexp)
+         (cons 16 'lower))
+        ((thing-at-point-looking-at
+          increment--decimal-number-regexp)
+         (cons 10 nil))))
+
+;;;###autoload
+(cl-defun increment-number-at-point (&optional arg)
+  "Increment the number at point by ARG or 1 if ARG is nil.  If called
+interactively, the universal argument can be used to specify ARG.  If
+the number at point has leading zeros then the width of the number is
+preserved."
+  (interactive "*p")
+  (save-match-data
+    (let (case-fold-search
+          (match-pair (increment--match-number-at-point)))
+      (unless match-pair
+        (let ((save-point (point)))
+          (unless (re-search-forward
+                   increment--number-regexp
+                   (line-end-position) :noerror)
+            (goto-char save-point)
+            (cl-return-from increment-number-at-point))
+          (setq match-pair (increment--match-number-at-point))))
+      (let* ((base      (car match-pair))
+             (hex-style (cdr match-pair))
+             (substr (buffer-substring-no-properties
+                      (match-beginning 3) (match-end 3)))
+             (sign (if (= (match-beginning 1) (match-end 1)) +1 -1))
+             (result (+ (* (string-to-number substr base) sign)
+                        (or arg 1))))
+        (replace-match
+         (increment--format-number-with-base
+          result base (- (match-end 2) (match-beginning 2))
+          substr hex-style))))))
+
+;;;###autoload
+(defun decrement-number-at-point (&optional arg)
+  "The same as `increment-number-at-point', but ARG is negated."
+  (interactive "*p")
+  (increment-number-at-point (- (or arg 1))))
+
+(provide 'increment)