bug#46621: Copy line

[Lars Ingebrigtsen]

Simen Heggestøyl <simenheg@runbox.com> writes:

>> I've now added this command to Emacs 29 as `duplicate-line'.
>
> Cool! I've had a similar command defined locally since 2015 (which I've
> found so useful over time that I've given it a short global keybinding).
>
> I have some suggestions that I think make the command even more useful:
>
> - Making it more DWIM'y by having it duplicate the region instead when
>   it's active   (perhaps giving it a more general name like
>   `duplicate-thing`, `duplicate-dwim`, or maybe just `duplicate`).

That makes sense, but there are some edge conditions here that the
current implementation avoids by using a "line" definition.  That is, if
we're at the final line in the buffer, and there's no newline at the
end, `duplicate-line' will add one.  That is, it's really line oriented,
and not region oriented, and making it do regions, too, would possibly
make it more confusing.

Unless we ensure a newline at the end of all the regions we paste in.

> - Having point end up at the duplicated line instead of the original
>   one, since that's the line you usually want to edit (in my
>   experience).

Yes, that's true.

> - With a prefix argument, comment out the original line/region after
>   duplicating it. This is perhaps a bit too specialized to be useful in
>   general compared to the other two suggestions, though I've found it
>   very useful personally.

I think that sounds a bit too specialised. 

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no