Copy the functions from diredp I depend on into appropriate packages

[Fuco1]

This could be called dired-interactive or something similar, with enhanced versions of the original commands. And it could provide a remap.

• [ ] diredp-marked
• [ ] diredp-next-subdir, mostly the wrap-around behaviour
• [ ] diredp-prev-subdir, mostly the wrap-around behaviour
• [x] diredp-mark-region-files mark or unmark files in region (built-in behaviour of dired-mark)

[dieggsy]

@Fuco1 seems like vanilla emacs does marking/unmarking of files in region by default? (Select region, dired-mark)

[Fuco1]

@dieggsy Sweet :) Yea, maybe the other functions also already work like "expected". So we can tick the last one off the list at least.