GNU bug report logs - #45199
28.0.50; [PATCH] Make goto-char offer the number at point as default

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Daniel Martín <mardani29 <at> yahoo.es>
To: bug-gnu-emacs <at> gnu.org
Subject: 28.0.50; [PATCH] Make goto-char offer the number at point as default
Date: Sat, 12 Dec 2020 17:40:23 +0100

[Message part 1 (text/plain, inline)]

My use case (there may be many) comes from working with PDFs at a low
level.  If you open a PDF file in fundamental-mode, towards the end of
the file you'll see text that resembles the following:

xref
0 26
0000000000 65535 f 
0000006459 00000 n 

This is a table where the first column contains file offsets that point
to where the PDF objects are defined.  I wanted to place the point on
the "0000006459", do M-g c, and easily go to file offset 6459 to see the
definition of the PDF object number 1 ("1 0 obj").  goto-char is useful
here because PDF files are open as unibyte in Emacs.

If you also find the behavior generally useful, feel free to install it
for Emacs 28.

Thanks.

[0001-Make-goto-char-offer-the-number-at-point-as-default.patch (text/x-patch, attachment)]

Message #8 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Daniel Martín <mardani29 <at> yahoo.es>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sat, 12 Dec 2020 20:05:42 +0100

Daniel Martín <mardani29 <at> yahoo.es> writes:

> * src/editfns.c (Fgoto_char): Expand the interactive definition of
> goto-char to offer the number at point as default.

I think this makes sense, but:

> -DEFUN ("goto-char", Fgoto_char, Sgoto_char, 1, 1, "NGoto char: ",
> +DEFUN ("goto-char", Fgoto_char, Sgoto_char, 1, 1,
> +         "(if (and current-prefix-arg (not (consp current-prefix-arg)))\
> +              (list (prefix-numeric-value current-prefix-arg))\
> +            (let* ((default\
> +	             (save-excursion\
> +	               (skip-chars-backward \"0-9\")\
> +	               (if (looking-at-p \"[0-9]\")\
> +	                   (string-to-number\
> +	                   (buffer-substring-no-properties\
> +	                   (point)\
> +	                   (progn (skip-chars-forward \"0-9\")\
> +		                  (point))))))))\
> +              (list (read-number \"Goto char: \" default))))",

I think it would be better to put this in a helper function in subr.el,
for instance.

And there's also `number-at-point', could perhaps be used here?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #11 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Daniel Martín <mardani29 <at> yahoo.es>
To: Lars Ingebrigtsen <larsi <at> gnus.org>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sun, 13 Dec 2020 02:23:13 +0100

[Message part 1 (text/plain, inline)]

Lars Ingebrigtsen <larsi <at> gnus.org> writes:
>
> I think it would be better to put this in a helper function in subr.el,
> for instance.
>
> And there's also `number-at-point', could perhaps be used here?

Oh, I forgot about number-at-point.  It extracts numbers that don't make
sense here (like floating point or negative numbers), but we can easily
filter them with natnump.  I've attached a new patch; do you feel it's
still necessary to extract the logic in a helper?

[0001-Make-goto-char-offer-the-number-at-point-as-default.patch (text/x-patch, attachment)]

Message #14 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Daniel Martín <mardani29 <at> yahoo.es>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sun, 13 Dec 2020 14:14:19 +0100

Daniel Martín <mardani29 <at> yahoo.es> writes:

> Oh, I forgot about number-at-point.  It extracts numbers that don't make
> sense here (like floating point or negative numbers), but we can easily
> filter them with natnump.  I've attached a new patch; do you feel it's
> still necessary to extract the logic in a helper?

Yeah, I'd still rather have a helper function -- putting several lines
of Lisp code in a string in C isn't optimal.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #17 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Daniel Martín <mardani29 <at> yahoo.es>
To: Lars Ingebrigtsen <larsi <at> gnus.org>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sun, 13 Dec 2020 19:01:24 +0100

[Message part 1 (text/plain, inline)]

Lars Ingebrigtsen <larsi <at> gnus.org> writes:
>
> Yeah, I'd still rather have a helper function -- putting several lines
> of Lisp code in a string in C isn't optimal.

OK, done.

[0001-Make-goto-char-offer-the-number-at-point-as-default.patch (text/x-patch, attachment)]

Message #20 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Robert Pluim <rpluim <at> gmail.com>
To: Daniel Martín <mardani29 <at> yahoo.es>
Cc: Lars Ingebrigtsen <larsi <at> gnus.org>, 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Mon, 14 Dec 2020 11:16:29 +0100

Daniel Martín <mardani29 <at> yahoo.es> writes:

> Lars Ingebrigtsen <larsi <at> gnus.org> writes:
>>
>> Yeah, I'd still rather have a helper function -- putting several lines
>> of Lisp code in a string in C isn't optimal.
>
> OK, done.
>

The docstring for the function needs to mention the new behaviour as
well.

Robert

Message #23 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Daniel Martín <mardani29 <at> yahoo.es>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Mon, 14 Dec 2020 17:17:29 +0100

Daniel Martín <mardani29 <at> yahoo.es> writes:

> Lars Ingebrigtsen <larsi <at> gnus.org> writes:
>>
>> Yeah, I'd still rather have a helper function -- putting several lines
>> of Lisp code in a string in C isn't optimal.
>
> OK, done.

Great; I've now applied this to Emacs 28 (but made the helper function
an internal function, and altered the doc string like Robert suggested).

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #32 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Juri Linkov <juri <at> linkov.net>
To: Daniel Martín via "Bug reports for GNU Emacs, the
 Swiss army knife of text editors" <bug-gnu-emacs <at> gnu.org>
Cc: Lars Ingebrigtsen <larsi <at> gnus.org>, 45199 <at> debbugs.gnu.org,
 Daniel Martín <mardani29 <at> yahoo.es>
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Mon, 14 Dec 2020 21:29:08 +0200

>> Yeah, I'd still rather have a helper function -- putting several lines
>> of Lisp code in a string in C isn't optimal.
>
> OK, done.

Shouldn't goto-line use the same function to read a number?
The first version of your patch used the code similar to
goto-line-read-args, so wouldn't it make sense to use the
new function in goto-line-read-args as well?

Message #38 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Juri Linkov <juri <at> linkov.net>
Cc: "Daniel Martín via Bug reports for GNU Emacs, the Swiss
 army knife of text editors" <bug-gnu-emacs <at> gnu.org>, 45199 <at> debbugs.gnu.org,
 Daniel Martín <mardani29 <at> yahoo.es>
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Tue, 15 Dec 2020 07:30:57 +0100

Juri Linkov <juri <at> linkov.net> writes:

>>> Yeah, I'd still rather have a helper function -- putting several lines
>>> of Lisp code in a string in C isn't optimal.
>>
>> OK, done.
>
> Shouldn't goto-line use the same function to read a number?
> The first version of your patch used the code similar to
> goto-line-read-args, so wouldn't it make sense to use the
> new function in goto-line-read-args as well?

Reusing it directly would be awkward, but goto-line-read-args could
indeed use number-at-point.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #44 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Juri Linkov <juri <at> linkov.net>
To: Lars Ingebrigtsen <larsi <at> gnus.org>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sun, 20 Dec 2020 10:55:33 +0200

[Message part 1 (text/plain, inline)]

>> Shouldn't goto-line use the same function to read a number?
>> The first version of your patch used the code similar to
>> goto-line-read-args, so wouldn't it make sense to use the
>> new function in goto-line-read-args as well?
>
> Reusing it directly would be awkward, but goto-line-read-args could
> indeed use number-at-point.

Here's a patch where it uses number-at-point:

[goto-line-read-args-number-at-point.patch (text/x-diff, inline)]

diff --git a/lisp/simple.el b/lisp/simple.el
index f79543058b..e17f2b0fc2 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1276,15 +1276,8 @@ goto-line-read-args
   (if (and current-prefix-arg (not (consp current-prefix-arg)))
       (list (prefix-numeric-value current-prefix-arg))
     ;; Look for a default, a number in the buffer at point.
-    (let* ((default
-             (save-excursion
-               (skip-chars-backward "0-9")
-               (if (looking-at "[0-9]")
-                   (string-to-number
-                    (buffer-substring-no-properties
-                     (point)
-                     (progn (skip-chars-forward "0-9")
-                            (point)))))))
+    (let* ((number (number-at-point))
+           (default (and (natnump number) number))
            ;; Decide if we're switching buffers.
            (buffer
             (if (consp current-prefix-arg)

[Message part 3 (text/plain, inline)]

Also this patch adds the same useful property from goto-line to goto-char.
When there is no number at point, then M-n gets the current char position
number for editing, so the user can decrease or increase it
relative to the current position:

[goto-char-default-point.patch (text/x-diff, inline)]

diff --git a/lisp/subr.el b/lisp/subr.el
index 275e224b55..c7b7ac6444 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2828,7 +2828,7 @@ goto-char--read-natnum-interactive
       (list (prefix-numeric-value current-prefix-arg))
     (let* ((number (number-at-point))
            (default (and (natnump number) number)))
-      (list (read-number prompt default)))))
+      (list (read-number prompt (list default (point)))))))
 
 
 ;; Behind display-popup-menus-p test.

Message #47 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Juri Linkov <juri <at> linkov.net>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sun, 20 Dec 2020 18:55:09 +0100

Juri Linkov <juri <at> linkov.net> writes:

> Here's a patch where it uses number-at-point:

Looks good to me.

> Also this patch adds the same useful property from goto-line to goto-char.
> When there is no number at point, then M-n gets the current char position
> number for editing, so the user can decrease or increase it
> relative to the current position:

Yeah, that sounds useful.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #50 received at 45199 <at> debbugs.gnu.org (full text, mbox):

From: Juri Linkov <juri <at> linkov.net>
To: Lars Ingebrigtsen <larsi <at> gnus.org>
Cc: 45199 <at> debbugs.gnu.org
Subject: Re: bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at
 point as default
Date: Sun, 20 Dec 2020 22:06:13 +0200

>> Here's a patch where it uses number-at-point:
>
> Looks good to me.
>
>> Also this patch adds the same useful property from goto-line to goto-char.
>> When there is no number at point, then M-n gets the current char position
>> number for editing, so the user can decrease or increase it
>> relative to the current position:
>
> Yeah, that sounds useful.

Now pushed to master.

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