Re: MacOS X: Not all Alt keys are equal?

[Peter Breitfeld]

Lars-Johan Liman wrote:

> Hi!
>
> I'm a veteran Emacs user (how many of you used Emacs on TOPS-20? ;-),
> and mostly an X11 user under *nix, and I've been using various Emacsen
> under MacOS X the past few years.
>
> My problem is that I want to map the Alt keys to allow for input of
> special characters. (A Swedish Mac keyboard maps, e.g., vertical bar
> (pipe) to Alt-7, and backslash to Alt-Shift-7).
>
> I just tried the emacsformacosx.org package, and it was very promising
> until I noticed the following.
>
> By setting
>
> (custom-set-variables
>  '(ns-alternate-modifier (quote none)))
>
> in my .emacs file, I got the disired behaviour on the _left_ Alt
> key. Alt-7 produces pipe, Alt-Shift-7 produces backslash. Fine!
>
> Now, to make the _right_ Alt key behave the same way, I tried adding
>
>  '(ns-right-alternate-modifier (quote none))
>
> to the config, as in
>
> (custom-set-variables
>  '(ns-alternate-modifier (quote none))
>  '(ns-right-alternate-modifier (quote none)))
>
> One would now believe that it would work. It does not.
>
> It's true that I get the "Alt" behaviour, but only to some extent. Now
> rAlt-7 (rightAlt-7) gives me pipe (fine!), but rAlt-Shift-7 does not
> give me the expected backslah, it gives me forwardslash, which is what
> you get with just Shift-7 on a Swedish keyboard. The same goes for
> rAlt-8 and rAlt-9 which give brackets "[" and "]" respectively, but the
> corrseponding braces "{" and "}" exepcted from rAlt-Shift-8 and
> rAlt-Shift-9 show up only as the dull parentheses "(" and ")". Footnote *)
>
> Conclusion: the Alt-function for the right Alt key does not work in
> conjunction with Shift, but the left one does.
>
> Now I just found out that there is yet another value for the variable,
> which is "left", which means that rAlt shall have the same function as
> lAlt. When I set it to that, it _DOES_ work! But then, I cannot have a
> different function on lAlt. Duh!
>
> Why are not all Alt keys created equal? ;-) What did I miss?
> How can I make my lAlt be "meta" and my rAlt be "none" with shift
> function intact?
>
> ... or, is this a bug?
>
> Platform:
>
> Darwin 10.6.0 Darwin Kernel Version 10.6.0: Wed Nov 10 18:13:17 PST 2010; 
> root:xnu-1504.9.26~3/RELEASE_I386 i386
>
> Emacs:
>
> Emacs-23.3-universal-10.6.6.dmg
>
>               Best regards,
>                 /Lars-Johan Liman
>
> *) Paretheses are "shifted" one step to the left on a Swedish keyboard,
>    compared to a US or UK one, so the numbers are actually correct.
> #-------------------------------------------------------------------------
> # Lars-Johan Liman, M.Sc.      ! E-mail: emacshelp@cafax.se
> # Cafax AB                 ! HTTP  : //www.cafax.se/
> # Computer Consultants, Sweden         ! Voice : +46 8 - 564 702 30
> #-------------------------------------------------------------------------
>

Lars,
Inspecting customize-group ns I found the following settings:

Variable                                 Status 
------------------------------------------------------
ns-control-modifier: control             (STANDARD)
ns-command-modifier: meta                (CHANGED in my .emacs)

ns-alternate-modifier: 'meta             (CHANGED, but not in my .emacs,
                                         I didn't find where it was set)

Help on this variable says: defined in C Source Code. It's value is nil

ns-right-alternate-modifier:
  Use the value of ns-alternate-modifier (STANDARD)
 Help says: It's value is left

I use the same Emacs-version as you do with a german keyboard. On my
iMac left and right alt-keys behave identical.
-- 
_________________________________________________________________
Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de