How to make `M-<' not set mark?

How to make `M-<' not set mark?

[Rodolfo Medina]

Normally, the `M-<' and `M->' commands automatically set a new mark.  How can I
prevent that?

Thanks for any help
Rodolfo

Re: How to make `M-<' not set mark?

[Rupert Swarbrick]

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Rodolfo Medina <rodolfo.medina@gmail.com> writes:

> Normally, the `M-<' and `M->' commands automatically set a new mark.
> How can I prevent that?
>
> Thanks for any help
> Rodolfo

Well, C-h f M-< gives:

-----
beginning-of-buffer is an interactive compiled Lisp function in `simple.el'.
It is bound to <begin>, <C-home>, M-<.
(beginning-of-buffer &optional ARG)

Move point to the beginning of the buffer; leave mark at previous position.
With C-u prefix, do not set mark at previous position.
With numeric arg N, put point N/10 of the way from the beginning.

If the buffer is narrowed, this command uses the beginning and size
of the accessible part of the buffer.

Don't use this command in Lisp programs!
(goto-char (point-min)) is faster and avoids clobbering the mark.
-----

So I'd recommend either hitting C-u beforehand, or (looking at section
21.12 of the elisp manual) do something like

(global-set-key (kbd "M-<")
                (lambda () (beginning-of-buffer '(4))))

or indeed

(global-set-key (kbd "M-<")
                (lambda () (goto-char (point-min))))



Rupert

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Re: How to make `M-<' not set mark?

[Rodolfo Medina]

Rodolfo Medina <rodolfo.medina@gmail.com> writes:

>> Normally, the `M-<' and `M->' commands automatically set a new mark.
>> How can I prevent that?



Rupert Swarbrick <rswarbrick@gmail.com> writes:

> Well, C-h f M-< gives:
>
> [...]
>
> So I'd recommend either hitting C-u beforehand, or (looking at section
> 21.12 of the elisp manual) do something like
>
> (global-set-key (kbd "M-<")
>                 (lambda () (beginning-of-buffer '(4))))
>
> or indeed
>
> (global-set-key (kbd "M-<")
>                 (lambda () (goto-char (point-min))))



I copied the definition of `beginning-of-buffer' from the file simple.el and
commented out the part related to mark:


(defun my-beginning-of-buffer (&optional arg)
  (interactive "P")
;  (or (consp arg)
;      (and transient-mark-mode mark-active)
;      (push-mark))
  (let ((size (- (point-max) (point-min))))
    (goto-char (if (and arg (not (consp arg)))
		   (+ (point-min)
		      (if (> size 10000)
			  ;; Avoid overflow for large buffer sizes!
			  (* (prefix-numeric-value arg)
			     (/ size 10))
			(/ (+ 10 (* size (prefix-numeric-value arg))) 10)))
		 (point-min))))
  (if arg (forward-line 1)))


, then bound `M-<' to the new definition:

(global-set-key (kbd "M-<") 'my-beginning-of-buffer)


.  It seems to work all right.
Rodolfo

Re: How to make `M-<' not set mark?

[Rupert Swarbrick]

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Rodolfo Medina <rodolfo.medina@gmail.com> writes:
> I copied the definition of `beginning-of-buffer' from the file simple.el and
> commented out the part related to mark:
>
<SNIP>
>
> , then bound `M-<' to the new definition:
>
> (global-set-key (kbd "M-<") 'my-beginning-of-buffer)
>
>
> .  It seems to work all right.
> Rodolfo

Hmm, a conceptually neater way to me would be something like:

(defun my-beginning-of-buffer (&optional arg)
  (beginning-of-buffer (or arg '(4))))

and setting M-< as you do. However, this does mean that (unlike your
code), the mark is set if you use crazy prefix args to jump back 50% of
the file or whatever.

I guess the question is whether you'd prefer to have a local copy of a
core defun (which I find a bit icky) or to have the desired behaviour
with prefix argument, which I don't think you can get without completely
redefining beginning-of-buffer as you do.

Rupert

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