bug#64574: [PATCH] Support not jumping to bol in beginning-of-defun

[Eli Zaretskii <eliz@gnu.org>]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Date: Tue, 11 Jul 2023 14:15:35 -0400
> 
> As mentioned in the commit, this default behavior by
> beginning-of-defun is undesirable in some languages and major modes.
> I'm thinking of OCaml in particular here, but it's also arguably
> unwanted in Python and C++ as well, where defs may be indented inside
> class definitions.  Let's let users and major modes make this decision
> on a case-by-case basis.

Such optional behavior is fine by me, but is there any evidence enough
people will want it?  Can you gather some feedback about that?

> +(defvar beginning-of-defun-go-beginning-of-line t

Why not defcustom?

And I would use a shorter name, like beginning-of-defun-go-bol.

> +  "If non-nil, `beginning-of-defun' runs `beginning-of-line' at the end.

This describes implementation, not the behavior.  It also assumes
everyone knows what exactly beginning-of-line does (think RTL text).

> +By default, `beginning-of-defun' jumps to the beginning of the
> +line with `beginning-of-line' after finding the start of the
> +defun.

I see no reason to tell in the doc string how exactly the function
goes to BOL.  It can even be a problem if at some future point we
decide to change the implementation.

> +For languages where defuns may be indented inside nested
> +structures like classes or modules, this behavior may be
> +undesirable.  Major modes for such languages can set this
> +variable to nil to avoid it.")

Not sure we should leave this to major modes and not to the individual
users.

Thanks.