bug#67036: 30.0.50; treesit-forward-sexp not working properly in ruby-ts-mode

[Dmitry Gutov]

On 27/11/2023 19:06, Juri Linkov wrote:
> > > >    +  # from "elsif" and "then" C-M-f should jump to next "elsif"/"else"
> > > >      if a == 2 then
> > > >        puts "hello"
> > > >      elsif a == 3
> >
> > Try out the change referenced above, but it doesn't do exactly
> > this. Because the tree-sitter parse tree doesn't match the intuition you
> > described above.
>
> Thanks for adding "then" and "else" that works not bad.
> Then "elsif" could be added as well.

You can try it and report back. My impression is that it made navigation 
worse: the "elsif" nodes are not siblings of one another, they are 
nested. So it doesn't exactly match your expectations.

> > > > +# when point is after @, C-M-f should jump to the end of symbol
> > > >    zzz @abc,
> > > >        4
> >
> > This is something that would need to be changed somewhere inside
> > treesit-forward-sexp (or treesit--navigate-thing). The default forward-sexp
> > behaves differently when in the middle of a symbol.
>
> Agreed, more general changes are needed when point is inside symbols,
> strings, comments, etc.

This is regarding behavior "inside" a thing as understood by treesit. 
Unrelated to Emacs's syntactic entities.

> > Also, interactive forward-sexp never reports "No next sexp" when inside
> > parens or begin...end. It will do forward-up-list instead.
>
> On the one hand, it's inconsistent with the default non-treesit behavior of
> forward-sexp.  On the other hand, the default behavior is too annoying
> when it screams all the time with "Containing expression ends prematurely!"
> instead of doing something useful.

Looks like I have been spoiled by Paredit's paredit-forward which 
catches such errors and does the appropriate thing. Might be nice to 
bring this behavior to Emacs as forward-sexp-command, for example.

> > > >      def begin
> > > >      end
> > > >    end
> > > > @@ -522,6 +530,9 @@ def qux
> > > >      puts "Japanese translation: #{orig_text} => #{trans_text}"
> > > >    end
> > > >    +# C-M-f on '[' doesn't jump to after ']'
> > > > +hash['key']
> > > > +
> >
> > As discussed previously, there is no specific node which spans from [ to
> > ]. Some custom code could probably be written (there *are* leaf nodes for [
> > and ]), but the current capabilities of treesit-thing-settings don't offer
> > a good way to plug that in.
>
> Like for point inside strings, this might require more general changes
> that take into account syntax tables.

Possibly, but I expect a solution that doesn't use the syntax table 
would be tried first.