bug#11011: Binding S-TAB

bug#11011: Binding S-TAB

[Antoine Levitt]

From a posting on emacs-devel:

Antoine Levitt <antoine.levitt@gmail.com>:

> Alright, I thought (kbd "S-TAB") would do the right thing, but
> apparently not. I'm thoroughly confused by emacs keybinding system.

Chong Yidong <cyd@gnu.org>:

> I think this is a bug in kbd.  It doesn't seem to handle TAB with
> modifiers right.  Please file a bug.

bug#11011: Binding S-TAB

[David De La Harpe Golden]

On 14/03/12 07:12, Antoine Levitt wrote:
>  From a posting on emacs-devel:
>
> Antoine Levitt<antoine.levitt@gmail.com>:
>
>> Alright, I thought (kbd "S-TAB") would do the right thing, but
>> apparently not. I'm thoroughly confused by emacs keybinding system.
>
> Chong Yidong<cyd@gnu.org>:
>
>> I think this is a bug in kbd.  It doesn't seem to handle TAB with
>> modifiers right.  Please file a bug.
>
>
>
>

works for me (tm). what platform are we talking about?

bug#11011: Binding S-TAB

[Antoine Levitt]

14/03/12 09:53, David De La Harpe Golden
> On 14/03/12 07:12, Antoine Levitt wrote:
>>  From a posting on emacs-devel:
>>
>> Antoine Levitt<antoine.levitt@gmail.com>:
>>
>>> Alright, I thought (kbd "S-TAB") would do the right thing, but
>>> apparently not. I'm thoroughly confused by emacs keybinding system.
>>
>> Chong Yidong<cyd@gnu.org>:
>>
>>> I think this is a bug in kbd.  It doesn't seem to handle TAB with
>>> modifiers right.  Please file a bug.
>>
>>
>>
>>
>
> works for me (tm). what platform are we talking about?

I'm using Ubuntu 11.10, with gnome/metacity. (on a french keyboard)

Typing S-TAB gives:
<backtab> (translated from <S-iso-lefttab>) is undefined

bug#11011: Binding S-TAB

[David De La Harpe Golden]

On 14/03/12 08:58, Antoine Levitt wrote:

>> works for me (tm). what platform are we talking about?
>
> I'm using Ubuntu 11.10, with gnome/metacity. (on a french keyboard)
>
> Typing S-TAB gives:
> <backtab>  (translated from<S-iso-lefttab>) is undefined


I'm just wrong, sorry for the noise - I overconfidently answered without 
rechecking my .emacs, I was actually doing:

(global-set-key (kbd "<backtab>") ...)

probably /because/ the more naive "S-" didn't work.

bug#11011: Binding S-TAB

[Stefan Kangas]

found 11011 28.0.50
tags 11011 + confirmed
thanks

Antoine Levitt <antoine.levitt@gmail.com> writes:

>>From a posting on emacs-devel:
>
> Antoine Levitt <antoine.levitt@gmail.com>:
>
>> Alright, I thought (kbd "S-TAB") would do the right thing, but
>> apparently not. I'm thoroughly confused by emacs keybinding system.
>
> Chong Yidong <cyd@gnu.org>:
>
>> I think this is a bug in kbd.  It doesn't seem to handle TAB with
>> modifiers right.  Please file a bug.

I can reproduce this on current master:

0. emacs -Q
1. (global-set-key (kbd "S-TAB") (lambda () (message "FOO")))
2. S-TAB

And see the following error: "<backtab> is undefined"

Best regards,
Stefan Kangas

bug#11011: Binding S-TAB

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Thu, 20 Aug 2020 12:06:44 -0700
> Cc: 11011@debbugs.gnu.org
> 
> 0. emacs -Q
> 1. (global-set-key (kbd "S-TAB") (lambda () (message "FOO")))
> 2. S-TAB
> 
> And see the following error: "<backtab> is undefined"

You say "S-TAB", but that's not the key you pressed.  You pressed
<backtab>, a function key, whereas S-TAB is a shifted ASCII character.
Try "C-S-i" instead (which will also reveal a minor unrelated bug in
your recipe ;-).

bug#11011: Binding S-TAB

[Drew Adams]

> > 0. emacs -Q
> > 1. (global-set-key (kbd "S-TAB") (lambda () (message "FOO")))
> > 2. S-TAB
> >
> > And see the following error: "<backtab> is undefined"
> 
> You say "S-TAB", but that's not the key you pressed.  You pressed
> <backtab>, a function key, whereas S-TAB is a shifted ASCII character.
> Try "C-S-i" instead (which will also reveal a minor unrelated bug in
> your recipe ;-).

I was going to say the same thing, or similar.

`TAB` = `C-i`.

`TAB' is not the same as `<tab>'.

(kbd "S-<tab>") => [S-tab]
(kbd "S-TAB")   => [33554441]

bug#11011: Binding S-TAB

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stefan Kangas <stefan@marxist.se>
>> Date: Thu, 20 Aug 2020 12:06:44 -0700
>> Cc: 11011@debbugs.gnu.org
>>
>> 0. emacs -Q
>> 1. (global-set-key (kbd "S-TAB") (lambda () (message "FOO")))
>> 2. S-TAB
>>
>> And see the following error: "<backtab> is undefined"
>
> You say "S-TAB", but that's not the key you pressed.  You pressed
> <backtab>, a function key, whereas S-TAB is a shifted ASCII
> character. Try "C-S-i" instead (which will also reveal a minor
> unrelated bug in your recipe ;-).

Hmm, now I see.  This stuff always manages to confuse me.  And I guess
it also managed to confused Chong Yidong...?

Not sure if there's anything to do here, if this is as it should be.
Notabug?

Best regards,
Stefan Kangas

bug#11011: Binding S-TAB

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Thu, 20 Aug 2020 14:41:19 -0700
> Cc: antoine.levitt@gmail.com, 11011@debbugs.gnu.org
> 
> > You say "S-TAB", but that's not the key you pressed.  You pressed
> > <backtab>, a function key, whereas S-TAB is a shifted ASCII
> > character. Try "C-S-i" instead (which will also reveal a minor
> > unrelated bug in your recipe ;-).
> 
> Hmm, now I see.  This stuff always manages to confuse me.  And I guess
> it also managed to confused Chong Yidong...?
> 
> Not sure if there's anything to do here, if this is as it should be.
> Notabug?

Yes, I think this is just a confusing subtlety of function keys vs
ASCII keys on a modern keyboard.  The OP should have bound <backtab>,
not S-TAB.

bug#11011: Binding S-TAB

[Stefan Kangas]

tags 11011 notabug
close 11011
thanks

Eli Zaretskii <eliz@gnu.org> writes:

>> Not sure if there's anything to do here, if this is as it should be.
>> Notabug?
>
> Yes, I think this is just a confusing subtlety of function keys vs
> ASCII keys on a modern keyboard.  The OP should have bound <backtab>,
> not S-TAB.

Thanks, so I'm closing this bug report now.

Best regards,
Stefan Kangas

bug#11011: Binding S-TAB

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Thu, 20 Aug 2020 23:55:06 -0700
> Cc: antoine.levitt@gmail.com, 11011@debbugs.gnu.org
> 
> > Yes, I think this is just a confusing subtlety of function keys vs
> > ASCII keys on a modern keyboard.  The OP should have bound <backtab>,
> > not S-TAB.

Btw, binding <S-tab> would have also done TRT in that use case.

bug#11011: Binding S-TAB

[Drew Adams]

> Btw, binding <S-tab> would have also done TRT in that use case.

Yes.  IIUC, to be more exact, <backtab> takes care of two cases:
<S-tab> and <S-iso-lefttab>.

To get the effect of <backtab> for Emacs prior to 22 you had to
bind both of those keys ([S-tab] and [S-iso-lefttab]).