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

[arthur miller]

>> >> 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?

>>

>> Everyone who would like to customize it has to write their own.

>

>Why would someone want to customize a command that does its job well?

What kind of question is that? You are asking why would someone want to

customize Emacs? :-)

Obviously people have written packages to do something similar. Small

conventience might matter to people. With backward-up-list you have to

press at least one more time, or if you are in a doc string you have to

invoke it again.

>> Down-list? I don't think it is close to the end-of-list.

>

>Try it on a deeply-nested list, and you will see the difference.

Down list vill move you to the beginning of next list, not the end of a

list, it is a drastic difference, not comparable by any means:

(defun end-of-list ()

  "Move cursor to the beginning of current list.

Return the number of nested expressions the point was over or after."

  (interactive)

  (let ((parse-sexp-ignore-comments t)

      (num-skipped-sexps 0)

        (syntax (syntax-ppss)))| <- cursor before

    (unless (= 0 (nth 0 syntax)) ;; not in a list

      (when (nth 3 syntax) ;; in string

        (goto-char (nth 8 syntax)))

      (ignore-errors

        (progn

          ;; First account for the case the point is directly over a

          ;; beginning of a nested sexp.

          (ignore-errors

              (let ((p (point)))

              (forward-sexp 1)

              (forward-sexp -1)

              (when (> (point) p)

                (setq num-skipped-sexps 1))))

          (while

              (let ((p (point)))

              (forward-sexp 1)

              (when (> (point) p)

                (setq num-skipped-sexps (1+ num-skipped-sexps))))))))

    num-skipped-sexps))

Down-list puts cursor after the next open parenthesis: (|unless (= 0 ...

End-of-list puts cursor before the closing parenthesis of the let:

                   ( ... )

                (setq num-skipped-sexps (1+ num-skipped-sexps))))))))

    num-skipped-sexps|)) <-- cursor after the end-of-list

However, as Karthink pointed out up-list places cursor to the closing let

parenthesis so it is close, similar to backward-up-list, one C-b press

away from the end of a list, and it also handles the literal strings the

same way as backward-up-list (puts cursor after the closing string

quote). Btw, I wasn't using myself up-list, I was manipulating my cursor

by other means :).

Anyway, I still think it is an improvement to rename at least

elisp--beginning-of-sexp, to beginning-of-list.

Personally I also think beginning-of-list and end-of-list are slightly

more convenient and the connection between the name and what they do is

much more clear than backward-up-list and up-list. It might be just me,

I admit that one, at least I wasn't using those myself even though I

knew about them by the name. Obviously people who are using smartparens

are thinking similar (paredit does not have this either). Do a web

search and you will see questions on SX asking "how do I move cursor to

the end of list", and you will see Drew teaching them "you wish to move

out of list, up-list does that".

I don't understand why this response if I wish to add a small

convenience for users (and myself admittedly). There are so many other

small wrappers included in Emacs that does much less.

---

Från: Eli Zaretskii <eliz@gnu.org>
Skickat: den 10 september 2024 17:48
Till: arthur miller <arthur.miller@live.com>
Kopia: emacs-devel@gnu.org <emacs-devel@gnu.org>
Ämne: Re: Suggestion: two new commands: beginning-of-list and end-of-list

 

> From: arthur miller <arthur.miller@live.com>
> CC: "emacs-devel@gnu.org" <emacs-devel@gnu.org>
> Date: Tue, 10 Sep 2024 15:10:26 +0000
>
> >> 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?
>
> Everyone who would like to customize it has to write their own.

Why would someone want to customize a command that does its job well?

> >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.
>
> Down-list? I don't think it is close to the end-of-list.

Try it on a deeply-nested list, and you will see the difference.