Re: tree-sitter: conceptional problem solvable at Emacs' level?

[Konstantin Kharlamov]

On Sat, 2023-02-11 at 10:11 +0300, Konstantin Kharlamov wrote:
> On Sat, 2023-02-11 at 07:51 +0100, Theodor Thornhill wrote:
> > 
> > 
> > On 11 February 2023 07:36:26 CET, Konstantin Kharlamov <hi-angel@yandex.ru>
> > wrote:
> > > On Sat, 2023-02-11 at 09:25 +0300, Konstantin Kharlamov wrote:
> > > > On Sat, 2023-02-11 at 10:17 +0800, Po Lu wrote:
> > > > > Eli Zaretskii <eliz@gnu.org> writes:
> > > > > 
> > > > > > However, I meant the IDEs which are using tree-sitter and support
> > > > > > developing C/C++ programs.  I believe some do.
> > > > > 
> > > > > I think most of those have similar problems supporting macros.
> > > > > Who knows their names? I may be able to ask some of their users.
> > > > 
> > > > From my experience on and off work, there are just two IDEs (as in, not
> > > > editors)
> > > > used most widely for C++ code: QtCreator and Visual Studio. The first
> > > > you
> > > > discussed, the second is proprietary.
> > > > 
> > > > Then again, people most often code in C++ and C with text editors, in
> > > > that
> > > > case
> > > > popular choices from my experience: Sublime Text and VS Code. These two
> > > > have
> > > > don't use tree-sitter either.
> > > 
> > > I installed Sublime Text on my Archlinux and tested with the C++ code OP
> > > posted.
> > > 
> > > What I see is that ST does seem confused about indentation, while trying
> > > to
> > > make
> > > a newline right after `slots:` line.
> > > 
> > > However, if you try to make a newline after the `void someSlot() {};`
> > > line,
> > > it
> > > will use the indentation used on the previous line.
> > > 
> > > The default cc-mode in Emacs works similarly. The cc-ts-mode on the other
> > > hand
> > > doesn't make use of the previous indentation, and I think it should. It
> > > would
> > > resolve that problem and others, because in my experience it happens very
> > > often
> > > in C and C++ code that you want some custom indentation level, so you just
> > > make
> > > one and you expect the editor to keep it while creating more new lines.
> > > 
> > 
> > That last statement sounds easily solvable. Can you send me a short example
> > describing exactly what you want in a code snippet and I'll add it.
> > 
> > Thanks,
> > Theo
> 
> Thank you! The example is below, but please wait a bit just to make sure
> there's no opposition from other people, because I don't know if it works like
> this on purpose, or not.
> 
> Given this C++ code with weird class members indentation:
> 
>     class Foo {
>            int a;
>            bool b;
>     };
> 
> Now, suppose you put a caret after `bool b;` text and press Enter to make a
> new
> line (all tests are done with `emacs -Q`). The behaviour:
> 
> * cc-mode and Sublime Text: creates a newline with the indentation exactly as
> on
> the previous one.
> * cc-ts-mode: re-indents the `bool b;` line, then creates a new one with a
> custom indentation that is different from one on the `int a;` line.
> 
> The cc-mode and Sublime Text behaviour seems like less annoying to me, because
> if I wanted to reindent the prev. line, most likely I'd did it by pressing an
> indentation hotkey (e.g. `=` in Evil mode I use).

Oh, wait, though I mistakengly used c-mode instead of c++-mode. The c-mode 
works this way, it keeps prev. indentation, however c++-mode instead uses a new 
indentation. It's odd they behave differently, and it certainly is different 
from other modes (e.g. emacs-lisp-mode). In this case I think the question of 
whether it should re-use prev. line indentation, which I think the should.