Re: proposal: edit-rectangle

[John Mastro <john.b.mastro@gmail.com>]

John Wiegley <jwiegley@gmail.com> wrote:
> This is functionality I'd like to add to rect.el. It allows you to specify a
> rectangular region, and then edit just the contents of that rectangle in a
> separate buffer. When finished (C-c C-c), it replaces the old rectangle using
> insert-rectangle with the new contents.
>
> I'd appreciate comments on usability, fitness, etc.

Neat idea, I like it.

> --8<---------------cut here---------------start------------->8---
> (defvar edit-rectangle-origin)
> (defvar edit-rectangle-saved-window-config)
>
> (defun edit-rectangle (&optional start end)
>   (interactive "r")
>   (let ((strs (delete-extract-rectangle start end))
>         (mode major-mode)
>         (here (copy-marker (min (mark) (point)) t))

Instead of mark and point, should this use the start and end arguments?

Also, since the number of live markers has performance implications, I
think you should (set-marker <marker> nil) once you're done with it in
`restore-rectangle'.

>         (config (current-window-configuration)))
>     (with-current-buffer (generate-new-buffer "*Rectangle*")
>       (funcall mode)
>       (set (make-local-variable 'edit-rectangle-origin) here)
>       (set (make-local-variable 'edit-rectangle-saved-window-config) config)

You could use `setq-local' here.

>       (local-set-key (kbd "C-c C-c") #'restore-rectangle)
>       (mapc #'(lambda (x) (insert x ?\n)) strs)
>       (goto-char (point-min))
>       (pop-to-buffer (current-buffer)))))
>
> (defun restore-rectangle ()
>   (interactive)
>   (let ((content (split-string (buffer-string) "\n"))
>         (origin edit-rectangle-origin)
>         (config edit-rectangle-saved-window-config))
>     (with-current-buffer (marker-buffer origin)
>       (goto-char origin)
>       (insert-rectangle content))
>     (kill-buffer (current-buffer))
>     (set-window-configuration config)))
> --8<---------------cut here---------------end--------------->8---

The results are a bit awkward if you `restore-rectangle' with more lines
than you started with, but I don't have any ideas offhand for
obviously better behavior.

        John