On Tue, 2025-05-13 at 12:45 -0700, Yuan Fu wrote:
> Hey, sorry for the delay.
>
> > On May 10, 2025, at 3:16 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> >
> > > From: Konstantin Kharlamov <Hi-Angel@yandex.ru>
> > > Date: Thu, 01 May 2025 20:39:02 +0700
> > >
> > > After poking around I wrote a patch (attached).
>
> Thanks! LGTM. For some reason I can’t apply the patch on either
> emacs-30 or master. [1]

Oh, interesting.  I kind of know where the error is coming from, but
only partially.  The reason for the error is that the patch I sent was
applied over the patch for #78121 (which is pending btw 😊) as I'm
using them both for coding.   At the same time, I don't really
understand the source of the error as the same parameters work for me:

    ╰─λ git am --3way -- /tmp/1.patch
    Applying: typescript-ts: align ternary-chain branches (bug#78187)
    Using index info to reconstruct a base tree...
    M       lisp/progmodes/typescript-ts-mode.el
    M       test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
    Falling back to patching base and 3-way merge...
    Auto-merging test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
    Auto-merging lisp/progmodes/typescript-ts-mode.el

Either way, I redone the patch on top of the tree, please try this one

> > > Worth noting though, for
> > > some reason it doesn't work for ternary without starting colon,
> > > e.g.:
> > >
> > >    const a = cond1 ? 1 :
> > >      cond2 ? 2 :
> > >      cond3 ? 3 : 4;
> > >
> > > I'm unclear why, per my understanding the "standalone-parent" of
> > > the
> > > whole ternary chain (disregarding where the point is) is the
> > > `const a
> > > =` declaration.
>
> The standalone rule just keeps going up the parse tree until it finds
> a node that starts on a new line. In this case, if you start form
> cond3, it’ll go up until reaching the teneray_expression node
> containing cond2. This node starts on a new line so standalone-parent
> stops here. So the cond3 line uses the cond2 line as the anchor,
> instead of the “const a” line. If you add a cond4 line, it’ll use the
> cond3 line as anchor.
>
> There’re several ways to fix it. The best way is to add a new anchor
> to the presets that does what standalone-parent does, but
> additionally excludes some nodes. Something like (standalone-parent-
> excluding “regexp”). Then this can be used for both typescript and
> c/c++ (and java, etc).

Oh, I see, thank you!