kill the current line and preserving cursor position

Question

I'm using the slick-cut function (as answered here by itsjeyd) for killing the entire line with minimal keystrokes. It's defined like so :-

(defun slick-cut (beg end)
  (interactive
   (if mark-active
       (list (region-beginning) (region-end))
     (list (line-beginning-position) (line-beginning-position 2)))))

(advice-add 'kill-region :before #'slick-cut)

But, I noticed this behaviour, whenever I kill a line, the cursor will be positioned to the beginning of the next line.

Before killing line 28 :- After killing line 28 :- Is there a way one can modify the slick-cut function so that, after killing a line, the cursor column position is also preserved. Like so :-

If unable to preserve cursor position, is it possible to at least move the cursor position to the indentation level ?

Answer 1

Here's a version that does what you want. Just bind it to a key.

(defun xah-cut-line-or-region ()
  "Cut current line, or text selection.
When `universal-argument' is called first, cut whole buffer (respects `narrow-to-region').

URL `http://ergoemacs.org/emacs/emacs_copy_cut_current_line.html'
Version 2016-07-29-stackoverflow"
  (interactive)
  (if current-prefix-arg
      (progn ; not using kill-region because we don't want to include previous kill
        (kill-new (buffer-string))
        (delete-region (point-min) (point-max)))
    (if (use-region-p)
        (kill-region (region-beginning) (region-end) t)      
      (progn
        (kill-region (line-beginning-position) (line-beginning-position 2))
        (back-to-indentation)))))

Notice the (back-to-indentation) in the end. That does what you want. Thanks to @kaushalmodi for suggesting this.

Answer 2

Here's a version that remembers column position on kill whole line.

(defun sto/kill-whole-line ()
  "Kill whole line but retain cursor position instead of moving to start of next line."
  (interactive)
  (let ((n (current-column)))
    (kill-whole-line)
    ;; do not move-to-column if that will add whitespaces at the end of line
    (if (< n (- (line-end-position) (line-beginning-position)))
      (move-to-column n t)
      (end-of-line))))

(defun sto/kill-line-or-region ()
  "If no region is selected kill the current line otherwise kill region."
  (interactive)
  (if (use-region-p)
      (kill-region (region-beginning) (region-end) t)
    (sto/kill-whole-line)))

(global-set-key (kbd "C-S-k") 'sto/kill-line-or-region)