Re: treesit indentation "blinking"

["Herman, Géza" <geza.herman@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> [...]  Which is better indeed, but
> what c++-ts-mode does is not a catastrophe, either.

Maybe it's not a catastrophe, but it's far from behaving well.

Type this example into a c++-ts-mode buffer (I used "emacs -Q"):

--8<---------------cut here---------------start------------->8---
int main() {
for (;;) {
printf("Hello world\n");
}
}
--8<---------------cut here---------------end--------------->8---

This is how it will be indented as I wrote it here. c++-ts-mode doesn't
re-indent anything during typing, even though it had the chance to do
that, because electric-indent-mode is enabled by default, and
electric-indent-chars contains the necessary characters.

Or, another example. Put the "void foo() { }" part first into a
c++-ts-mode buffer, then write the main function:

--8<---------------cut here---------------start------------->8---
int main() {
int a = 0;
for (;;) {
printf("Hello!\n");
}
}

void foo() {
}
--8<---------------cut here---------------end--------------->8---

Again, c++-ts-mode doesn't indent anything.

If you change the example to contain "void foo();" instead of "void
foo() { }", then indenting happens during typing the main function.

If you try adding "int a = 0;" into the first example, then it will be
indented at typing the ";". But then for loop is still not get indented,
and the buffer will look like this:

--8<---------------cut here---------------start------------->8---
int main() {
  int a = 0;
for (;;) {
printf("Hello world\n");
}
}
--8<---------------cut here---------------end--------------->8---

If you start by adding an empty comment, and then write the first
example above the empty comment, the buffer will look like this:

--8<---------------cut here---------------start------------->8---
int main() {
  for (;;) {
printf("Hello world\n");
  }
}

/**/
--8<---------------cut here---------------end--------------->8---

Can you reproduce these? These happen both with emacs-29 and
several-day-old master with the latest tree-sitter-cpp (but it also
happens with a ~1 month-old tree-sitter-cpp).

Géza