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

[Konstantin Kharlamov <hi-angel@yandex.ru>]

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).