Re: Call for volunteers: add tree-sitter support to major modes

[Po Lu]

Theodor Thornhill <theo@thornhill.no> writes:

> Sure!
>
> (The following example is from the other tree-sitter implementation, but
> it would be as simple, if not simpler in the new one)
>
> Consider this code:
>
> ```
> (defun csharp-delete-method-at-point ()
>   "Deletes the method at point."
>   (interactive)
>   (when-let ((method (tree-sitter-node-at-point 'method_declaration)))
>     (delete-region (tsc-node-start-position method)
>                    (tsc-node-end-position method))))
> ```
>
> If point is _anywhere_ inside a method, this function will delete the
> whole thing.  It knows the beginning and end, and doesn't have to do
> anything else than returning the relevant points.  The same could be
> done with i.e. string, where if:
>
> ```
> "some string here where this | denotes where point is"
> ```
>
> You could create paredit-like functionality to delete _until_ the last
> quote, etc.  Compare them to Vims 'cip', 'dap' etc.  These are only
> trivial examples, but you could also imagine creating refactoring
> functions where you extract variables and insert them in the scope of
> other functions and so forth.  The huge thing here is that you have the
> _actual_ parse tree.  Indentation is also now simpler, more correct.
> There are all sorts of things we could evolve from here.  Font-lock is
> just because that is the clearest, easiest and fastest benefit.

Thank you for the detailed explanation.