bug#46621: Copy line

[Mattias Engdegård]

23 juni 2022 kl. 17.20 skrev Lars Ingebrigtsen <larsi@gnus.org>:

> I think that means that it might make sense to keep the command as is
> (point movement wise).  I.e., if we move point to the duplicated line,
> then hitting `H-y' a whole bunch of times would leave point at the final
> line.

Right. Again, it is slightly more consistent to have it duplicate "below" than 
"above" so I weakly favour this way of working, but don't take my word for it 
-- try it out in anger.

> If we decide to move to the duplicated line, but keep the same column --
> then that makes no sense in a region-sensitive context at all.  If you
> mark a word and hit `H-y', then there's no way to keep the "current
> column".

That's unavoidable because Emacs's region concept prevents the cursor from 
moving independently of the selection. (Same goes for most other modern editors 
although they use a slightly different selection paradigm.)
In no way does this diminish the utility of the command in either of its modes 
of usage.

> It makes no sense to mash up these two totally different
> things into one command, and people do complain about commands that make
> no sense.

But the semantics do make sense -- let's not look for problems that don't 
exist. It's like `upcase-dwim`: without an active region it acts on the current 
word, which is the most practical unit for that operation.

If it helps, call the new command `duplicate-dwim` or just `duplicate`. The 
user who only uses it to duplicate lines is unlikely to be disturbed by its 
other ways of functioning.