Subject: Re: bug#62158: treesit-end-of-defun error

From: Dmitry Gutov <[email-masked]>
Date: Mon, 20 Mar 2023 20:43:51 +0200

On 14/03/2023 00:04, Yuan Fu wrote:
> We tried that initially, but end-of-defun doesn’t have the notion of nested defuns, which leads to problems when end-of-defun-function recognizes nested defuns. In the following code
> 
> (defun xxx ()
>    |
>    (defun yyy () ...)
> 
>    (defun zzz () ...)
>    )
> 
> If point is at “|” and you call end-of-defun, you’d expect point to move to the end of yyy, but instead it moves to the end of xxx. That’s because end-of-defun first runs (beginning-of-defun -1) followed by (end-of-defun 1) to check if the starting point is in a defun or between two defuns. This is fine in non-nested defuns, but in this example, the point first goes to the beginning of xxx, then goes to the end of xxx. And end-of-defun thinks that we started in a defun and now is at an end of defun, job’s done, and finishes.
> 
> The plan is to improve end-of-defun to support nested defuns in Emacs 30. For now we rebind end-of-defun to treesit-end-of-defun.

That makes sense, thanks!

I guess one of the things to try is to call end-of-defun-function first, 
followed by beginning-of-defun-function. And see if the resulting 
position is below the original point.