Re: [Emacs-diffs] trunk r116461: Connect electric-indent-mode up with CC Mode. Bug #15478.

[Dmitry Gutov <dgutov@yandex.ru>]

On 30.03.2014 17:57, Alan Mackenzie wrote:

>> This could be considered a reason to improve the indent-line-function in
>> text-mode. `indent-relative' offers behavior that's pretty close. Maybe
>> it could be made to follow the behavior of auto-fill even closer.
>
> Notice, here, how we're no longer talking about electric indentation, but
> rather about newline-and-indent.  The two topics are distinct.

Yes, but I think we're discussing both in this thread. FWIW, I think 
we're in agreement about electric indentation on RET. See my message 
here, and also Stefan's reply:

http://lists.gnu.org/archive/html/emacs-devel/2014-03/msg00936.html
http://lists.gnu.org/archive/html/emacs-devel/2014-03/msg00957.html

> Yes, but how?  fundamental-mode is a non-programming mode, so the global
> key map needs RET set up for newline, C-j for newline-and-indent.  That
> leaves lots of mode key maps to be set up.  At this point, your
> suggestion and mine become the same.

Maybe.

> I usually think of html, markdown, and such like, as the "etc." in
> "programming modes (etc.)".

Yeah, okay. Which other modes exactly need newline-and-indent on RET 
could be a matter of debate, but one possible criteria is "mode has a 
meaningful/specialized indentation function".

> If you edit the non-code blocks a lot in text mode, `fill-paragraph' is
> _exactly_ what's wanted to restore the filling.

If the filling algorithm is perfect, then yes, it could be what's wanted.

> I think RET should do the most natural sort of newline, and C-j the
> subsidiary one, whatever they may happen to be for a particular mode.

Sounds okay, I guess.

>> As long as this new mode is divorced from electric-indent-mode, I'd be
>> happy.
>
> This is a key point.

It could be something called like `old-newline-keys-mode'. Appropriate 
major modes would swap RET and C-j bindings, and the above minor mode 
would force them all back to (RET C-j) -> (newline newline-and-indent).

>> This specific behavior is a consequence of using `newline-and-indent'.
>
> No, not at all.  It's a consequence of electric behaviour getting
> entangled with newline-and-indent.

It's the same if I disable `electric-indent-mode' but bind RET to 
`newline-and-indent'.

And if `electric-indent-mode' didn't do `-and-indent' but retained the 
electric indent on RET, a similar example is easy to demonstrate:

foo
   bar|

Press RET, see the same result.

IOW, text-mode could be considered in trouble if RET triggers call to 
indentation at any line.

> The two are completely non-competing situations.  RMS's happened because
> electric indentation was active where it shouldn't be.

AFAICT it's the opposite, but see the scenario above.

To quote the bug report: "and point is at the start of the second line"

> Your situation is
> a matter of binding (RET C-j) to ('newline 'newline-and-indent) the
> appropriate way round.  Don't confuse these.

Indeed, for my usage the above binding is sufficient.