Re: Suggestion: two new commands: beginning-of-list and end-of-list

[Eli Zaretskii <eliz@gnu.org>]

> From: arthur miller <arthur.miller@live.com>
> CC: "emacs-devel@gnu.org" <emacs-devel@gnu.org>
> Date: Mon, 9 Sep 2024 19:41:12 +0000
> msip_labels:
> 
> >I think we do have it: C-M-u, backward-up-list.  What's more, it works
> >not only in Lisp.  I use it all the time.
> 
> Yes you have. It works slightly differently when you are in a string, and it
> places cursor before the opening parenthesis, not after.

Right.  But I think what it does is very useful, since it can be
invoked repeatedly, each time moving up one level.

> >So I wonder why we need another function that does basically the same.
> 
> I think it makes sense to keep backward-up-list as it is, since it handles
> literal strings as it does. But the behaviour is controlled via special vars
> esape-strings and no-syntax-crossing. If we want similar command as
> beginning-of-string, we have to wrap it and let-bind those variables to
> change how it works.

Yes, but is that a problem?

> I am not sure, what is a symmetric function to move cursor to the end of list?

The converse of C-M-u is C-M-d, but it doesn't move to the end of a
list, it moves _inside_ one level.

> But as said in the previous mail: this function is *already* in Emacs, so it is
> already taking the memory in the process.  It is just not used more than
> once, and have *potential* to be used more. In other words, I suggest these
> two functions as a convenience, not because it is impossible to do something
> similar via some combination of other commands and variables.

It is IME confusing to have two similar functions that do _almost_ the
same job.

What do others think about this?

> By the way, why did all occasions of the word "expression" ended up surroneded
> with underscores in the online archive?

No idea.