bug#73404: 30.0.50; [forward/kill/etc]-sexp commands do not behave as expected in tree-sitter modes

[Eli Zaretskii <eliz@gnu.org>]

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> From: Theodor Thornhill <theo@thornhill.no>
> Cc: casouri@gmail.com, mickey@masteringemacs.org, 73404@debbugs.gnu.org,
>  monnier@iro.umontreal.ca
> Date: Sun, 05 Jan 2025 12:46:03 +0100
> 
> Juri Linkov <juri@linkov.net> writes:
> 
> > The command is 'forward-list'.  With 'list' it will do in ts-modes
> > the same that 'forward-list' already does in non-ts modes.
> 
> One issue I've had when exploring these things earlier is that I don't
> know the "spec" for how navigation in programming languages should work
> in Emacs. I mean, there are lots of examples in the source code, but no
> true specification. Should we possibly try to define some sane defaults
> here, so that it will be simpler to deal with idiosyncrasies of the tree
> sitter parsers? Lisp isn't in my experience the best language to define
> this, as it is just too simple. Also, many of the functions are related
> to word processing, like sentence, word, paragraph etc, which aren't
> really useful in programming, imo. What is a sentence in java, lisp, or
> python, for example? Also, maybe sexp is too lisp/ast-like of a term, so
> much so that it is hard to reason about what a sexp is or isn't.

Is this goal achievable in practice,l given the sometimes radical
differences between languages?  Maybe we only can have examples and
some dwim-ish behavior in most cases?