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bug#631: the M- notation suggestion
bug#631: the M- notation suggestion
Wed, 30 Jul 2008 01:49:01 -0700
This is a suggestion on emacs's usability.
Recently in discussion at gnu.emacs.help, the subject of Alt+‹key›
vs M-‹key› came up.
I think emacs's M-‹key› notation is one of emacs's a usability
problem, contributing to its often cited big leaning curve.
Here's some detailed argument on why i think this should be chaged.
Many emacs old users probably don't agree, but i thought it's good to
send in one opinion anyhow.
Emacs's M-‹key› Notation vs Alt+‹key› Notation
Xah Lee, 2008-07
Here're some reason i think emacs should adopt the Alt+‹key› and
Ctrl+‹key› notation throughout its documentation. (as opposed to
emacs's M-‹key› and C-‹key› notation)
The Alt+‹key› or Ctrl+‹key› notation is universal among
Windows and Linux. They account for about 95% of computers used word
wide. Note that the word “Alt” and “Ctrl” are the exact labels
printed on the Keys of PC Keyboards. PC Keyboards has probably more
than 99% of market share.
IDENTICAL TO KEY'S LABEL
Using a notation that contains the actual label on keyboard's keys is
much easier to understand. A beginning computer user, can read the
“Ctrl+‹key›” notation and figure out which keys to press.
Emacs's notation of “M-‹key›” and “C-‹key›” requires a
learning step, even for experienced programers. Even though it is a
minor one, but learning steps add up the complexity.
(Apple's computers, which account for about %4 marke share today,
also use a notation where the name or symbol appears on the labels of
Apple keyboard's keys exactly. (OSX's documentation uses the notaton
“Command-‹key›” and “Option-‹key›”. Application's
menus shows them as “⌘‹key›” and “⌥‹key›”. Both
the word “Command” and symbol “⌘” appear on the key's label,
same for “Option” and “⌥”.)
Meta Is Alt In Practice
By default on all major OSes in use (Windows and Linux and OSX),
emacs maps its Meta to Alt key. So, practically speaking, the Meta
key is the Alt key. (Aquamacs, perhaps the most widely used emacs
distro on OSX, by default has Alt for Meta.)
KEYBOARDS DON'T HAVE META KEY TODAY
The Meta key was one of the modifier key on obsolete keyboards used
by lisp machines in the 1980s. (for photos and detail, see: Why
Emacs's Keyboard Shortcuts Are Painful)
There is practically no keyboard today that has the Meta key. Sun
Microsystem's keyboard has a key labeled with a diamond “◆”.
Sun's official documentation refers to this key as Meta key. (e.g.
search http://docs.sun.com/ on “Meta key”.) Sun's keyboards have a
market share perhaps less than 0.01%.
For photos and more commentary on Sun's keyboard, see Computer
Historically, a “Meta+‹key›” shortcut in emacs can also be
invoked by “Esc ‹key›” or “Ctrl+[ ‹key›”. The design
was that way mostly because at the time, many terminals do not have
or support the Meta key, and Terminal is a primary application in
computer use in the 1980s. The other reason is that, in emacs's
implementation, the Meta+‹key› is simply a ASCII control character
sequence. Today, perhaps all terminal↗, console↗, Command line
interface↗ apps support Meta as Alt either by default or in a
The ability of pressing Esc for Meta might be still useful for some
people. Users who needed that feature could easily read about it in
emacs doc. (I myself used “Esc ‹key›” exclusively during
1998-2004, mostly because it was a one-brainless solution that works
on all telnet apps regardless of hardware, OS, or setup, and i
frequently need to use different machine, OS, or remote servers.)
A argument from user interface perspective, is that multiple
insignificant choices or options are not good because it increases
complexity and causes the user to sidetrack their focus on tasks. KDE
and Gnome, solved this problem for linuxes by adopting wholesale
Microsoft Window's interface starting about 1998. (before KDE and
Gnome, GUI apps on unix use a variety of “Windows Managers” that
has incompatible User Interfaces, each claiming superiority.)
Note: Whether to use the “M-‹key›” or “Alt+‹key›”
notation has little to do with “Esc ‹key›” feature.
PS Note that Microsoft Windows used to use the Alt-‹key› notation.
Only in recent years they changed the minus sign to plus sign.
Arguably, this is a good change because the plus sign better
indicates key combination.