> From: Yuan Fu <caso...@gmail.com>
> Date: Mon, 26 Aug 2024 19:53:51 -0700
> Cc: Ergus <spaci...@aol.com>,
> 72...@debbugs.gnu.org
>
>
>
> > On Aug 24, 2024, at 1:28 AM, Eli Zaretskii <e...@gnu.org> wrote:
> >
> > Ping! Any progress with this?
> >
> >> From: Yuan Fu <caso...@gmail.com>
> >> Date: Sat, 10 Aug 2024 22:10:01 -0700
> >> Cc: Ergus <spaci...@aol.com>,
> >> 72...@debbugs.gnu.org
> >>
> >>
> >>
> >>> On Aug 10, 2024, at 12:56 AM, Eli Zaretskii <e...@gnu.org> wrote:
> >>>
> >>>> Date: Thu, 08 Aug 2024 16:45:42 +0200
> >>>> From: Ergus via "Bug reports for GNU Emacs,
> >>>> the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> >>>>
> >>>>
> >>>> Hi:
> >>>>
> >>>> Using this code:
> >>>>
> >>>> ```
> >>>> int main()
> >>>> {
> >>>> abort(); /* 1 */
> >>>> abort(); /* 1 */
> >>>> }
> >>>> ```
> >>>>
> >>>> There is an inconsistency in the c++-ts-mode behavior of `forward-sexp`.
> >>>>
> >>>> When there is a comment at the end of the line, if I do `mark-sexp`
> >>>> (C-M-SPC) consecutively I get this selected regions:
> >>>>
> >>>> -----------------------------
> >>>> 1.
> >>>> abort();
> >>>>
> >>>> 2.
> >>>> abort(); /* 1 */
> >>>>
> >>>> 3.
> >>>> abort(); /* 1 */
> >>>> abort
> >>>>
> >>>> 4.
> >>>> abort(); /* 1 */
> >>>> abort()
> >>>>
> >>>> 5.
> >>>> abort(); /* 1 */
> >>>> abort();
> >>>>
> >>>> 6.
> >>>> abort(); /* 1 */
> >>>> abort(); /* 1 */
> >>>>
> >>>> -------------------------------
> >>>>
> >>>>
> >>>>
> >>>> But when there is NOT trailing comment
> >>>>
> >>>> ```
> >>>> int main()
> >>>> {
> >>>> abort();
> >>>> abort();
> >>>> }
> >>>> ```
> >>>>
> >>>> -------------------------------
> >>>> 1.
> >>>> abort();
> >>>>
> >>>> 2.
> >>>> abort();
> >>>> abort();
> >>>> -------------------------------
> >>>>
> >>>>
> >>>> It looks like in the fist example after 3 the sexp definition is more
> >>>> fine
> >>>> grained (similar to the previous c++-mode behavior) and it selects
> >>>> separately:
> >>>> the function name,
> >>>> the arguments
> >>>> the semicolon
> >>>> the comment
> >>>>
> >>>> But if there is no comment at the end, it always considers the complete
> >>>> line as a sexp (including the ;).
> >>>>
> >>>> For my use case I would prefer the old behavior because it is consistent
> >>>> with the current sexp definition in all emacs (with maybe the exception
> >>>> of python-mode). Because it is easier to copy function names or
> >>>> function calls with a few movements.
> >>>>
> >>>> However, if it is too difficult to reproduce the old behavior; then the
> >>>> new one may be implemented consistently.
> >>>
> >>> Yuan, any comments or suggestions?
> >>>
> >>> FWIW, I'm not sure this is a bug: what constitutes a "sexp" in C++
> >>> source code is not well-defined.
> >>
> >> Yeah I’ll look into this. And yeah there were some discussion around how
> >> should we define sexp in c++-ts-mode but there wasn’t a concrete
> >> conclusion (I don’t think it’s possible to come up with a concrete one
> >> anyway.) Still, if it can be made more convenient for common use-cases I’m
> >> more than happy to improve it. Just be aware that I’ll be super busy next
> >> week (and I still haven’t done the parse string feature) so it might take
> >> me a while to get back.
> >>
> >> Yuan
>
> I know the reason for the inconsistency now. Treesit-forward-sexp first
> checks whether point is in a “text” node, ie, comment or string; if so, it
> uses the default/normal forward-sexp function; if not, it uses the parse tree
> to go over sexp.
>
> In the first example, because there’s a comment right before point,
> treesit-forward-sexp thinks it’s in a text node, and used the normal
> forward-sexp function, which moved point after the next symbol.
>
> In the second example, because there’s no comment anymore,
> treesit-forward-sexp uses the parse tree to move the point; and since the
> next node after point is the statement line, it moves point over the whole
> line. When using the parse tree to move point, treesit-forward-sexp always
> moves in the same “level” in which that point is. Eg, when point is between
> two lines, treesit-forward-sexp moves over lines; if point is inside an
> argument list between two arguments, treesit-forward-sexp moves over each
> argument.
>
> If you want to just select the identifier or other more fine-grained
> movement, IMHO it’s probably better to use forward-word.
>
> I fixed the inconsistency so now treesit-forward-sexp in both example moves
> over the whole line. The fix is pushed to emacs-30.
Thanks.
No further comments, so I assume the bug is fixed, and I'm therefore
closing it.
