Re: [PATCH] Lazy wdired preprocessing

[Stefan Monnier <monnier@iro.umontreal.ca>]

> +(defvar wdired-perm-beg) ;; Column where the permission bits start
> +(defvar wdired-perm-end) ;; Column where the permission bits stop

I think this should use "--" in the names since they are internal variables.

>    (setq mode-name "Editable Dired")
> -  (add-function :override (local 'revert-buffer-function) #'wdired-revert)
> -  ;; I temp disable undo for performance: since I'm going to clear the
> -  ;; undo list, it can save more than a 9% of time with big
> -  ;; directories because setting properties modify the undo-list.
> -  (buffer-disable-undo)
> -  (wdired-preprocess-files)
> -  (if wdired-allow-to-change-permissions
> -      (wdired-preprocess-perms))
> -  (if (fboundp 'make-symbolic-link)
> -      (wdired-preprocess-symlinks))
> -  (buffer-enable-undo) ; Performance hack. See above.
> +  (setq revert-buffer-function 'wdired-revert)
>    (set-buffer-modified-p nil)

This reverts part of my recent change to the way we set
`revert-buffer-function` (most likely an oversight while merging my changes).

>    (setq buffer-undo-list nil)
> +  ;; find one column with permissions and set permision text boundaries
> +  (save-excursion
> +    (goto-char (point-min))
> +    (unless (re-search-forward dired-re-perms nil t 1)
> +      (wdired-abort-changes)
> +      (error "No files to be renamed - Exiting to Dired mode."))
> +    (goto-char (match-beginning 0))
> +    (setq-local wdired-perm-beg (current-column))
> +    (goto-char (match-end 0))
> +    (setq-local wdired-perm-end (current-column)))

I'd recommend you put this in a separate function.

> +  (define-key wdired-mode-map [remap self-insert-command] #'wdired--self-insert)

Why is this done here instead of in the definition of `wdired-mode-map`?

> +(defun wdired--point-at-perms-p ()
> +  (and (>= (current-column) wdired-perm-beg)
> +       (<= (current-column) wdired-perm-end)))

`current-column` can be somewhat costly, so we should refrain from
calling it twice gratuitously.  And here we can even take advantage of
the (rarely used and rarely applicable) multi-arg form of `<=` to fix
that "for free":

     (<= wdired-perm-beg (current-column) wdired-perm-end)

> +(defun wdired--self-insert ()
> +  (interactive)
> +  (if (wdired--point-at-perms-p)
> +    (when (not (get-text-property (line-beginning-position) 'front-sticky))
> +      (wdired--before-change-fn (line-beginning-position) (line-end-position))
> +      (setq unread-command-events (nconc (listify-key-sequence
> +                                          (this-command-keys))
> +                                         unread-command-events)))
> +    (call-interactively 'self-insert-command)))

I think this deserves a comment about why we look at `front-sticky`.
Better yet: move this test to a helper function to which you can give
a meaningful name (like `wdired--processed-p`).

Also, instead of using `unread-command-events`, you can just call the
appropriate command directly, no?

> -  (remove-hook 'kill-buffer-hook #'wdired-check-kill-buffer t)
> -  (remove-hook 'after-change-functions #'wdired--restore-properties t)
> -  (remove-function (local 'revert-buffer-function) #'wdired-revert))
> +  (remove-hook 'kill-buffer-hook 'wdired-check-kill-buffer t)
> +  (remove-hook 'before-change-functions 'wdired--before-change-fn t)
> +  (remove-hook 'after-change-functions 'wdired--restore-properties t)
> +  (setq-local revert-buffer-function 'dired-revert))

This also look like the merge wasn't done right.

>  (defun wdired-abort-changes ()
> -  "Abort changes and return to dired mode."
> +  "Abort changes and return to dired mode.  "

What happened here?


        Stefan