Subject: bug#62412: 29.0.60; strange c++ indentation behavior with tree sitter

From: João Távora <[email-masked]>
Date: Sat, 25 Mar 2023 16:23:35 +0000

"Herman, Géza" <[email-masked]> writes:

> On 3/25/23 12:43, João Távora wrote:
>>
>> There can be no "correct" indentation in a buffer with an invalid state.
>>
>> But there are heuristics.  Here, it can be argued that c++-mode's
>> heuristics are better.
> I agree. In my opinion, c++-mode's heuristics are good.

That's probably only because we're _used_ to c++-mode.  If we had been
using c++-ts-mode for years, we would be equally suprised.

> Tree-sitter support is new, it's expected that it won't work
> perfectly. Also, it doesn't have to handle any invalid program. But,
> while writing a program, it should handle indentation sensibly. I
> don't think that it's a good approach that everybody who uses electric
> indent should get used to the fact that whenever they writing a for
> loop, the line will jump around. It's a bad experience.

But writing a for loop from scratch is only one of the editing
activities you do in a C++ file.  Other activities involve editing
existing code.  In those situations, c++-ts-mode's heuristics could
"win".  Unless you're willing to posit that writing code from scratch is
more frequent than editing existing code, there's no right answer here.

> Anyways, feel free to close this issue if you think otherwise. I just
> disabled ';'-caused auto indenting, so I don't see this unpleasant
> behavior any more.

Yes, i'm inclined to think that c++-ts-mode shouldn't add any chars to
electric-indent-chars.  It's just not useful.

João