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

[Alan Mackenzie]

Hello, Dmitry.

On Mon, Mar 31, 2014 at 08:11:58PM +0300, Dmitry Gutov wrote:
> 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, I think we're in agreement with eachother, but not with Stefan.  He
has decided to conflate the RET/C-j bindings and electric-indent-mode,
and to have these bindings apparently flip each time e-i-m is called.
He's also decided to do this although there's never been any meaningful
discussion of it here, and there isn't going to be any.

> > 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".

Hmm.  I'm not sure that gets us very far, in practice.  What does
"meaningful/specialized" mean?  I'll be more specific: programming modes
which use syntactic indentation (i.e. most of them) and the various
markup-like modes which are "like" programming languages.

> > 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).

Again, Stefan has decided there will be no such new mode, and that its
functionality is going to be twisted up with electric-indent-mode, rather
than being independent of it.  It now seems us discussing this further
would just be a waste of time.


> >> 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.

Yes.  Again, if we're in a programming mode that's what we want nearly
all the time - it's what electric indentation is for (despite all the
disadvantages of doing it on \n).  In non-programming modes it's what we
don't want.  It now seems Somebody (tm) is going to have to trawl through
all major modes disabling electric indentation for lots of them.

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

Yes indeed.

-- 
Alan Mackenzie (Nuremberg, Germany).