Why Emacs's Keyboard Shortcuts Are Painful

Xah Lee, 2007-07

A important aspect in designing a keyboard shortcut set, for a application that has intensive, repetitive, prolonged human-machine interaction (such as coding and text editing), is to consider ergonomic principles. Specifically: allocate keyboard shortcuts for the most frequently used commands, and, the top most frequently used commands should have most easily-pressed keystrokes. For example, they should be on the home row.

This article shows why Emacs's keyboard shortcut set is the worst with respect to ergonomics.

The Swapping of Control and Meta Modifiers

Emacs's keyboard shortcuts is very inefficient. The primary cause is because, emacs's keyboard shortcuts are designed with a keyboard that practically has the Ctrl and Alt key positions swapped.

The Space-cadet keyboard. ❐ Source

The common keyboard used around emacs era in the 1980s are those keyboards from Lisp Machines. (see Space-cadet keyboard) The keyboard on lisp machines have the Control key right besides the space bar (similar to the position of Alt keys on PC keyboards), and Meta to the left of Control. So, the Control key is the primary modifier, and the Meta is secondary to Control. This is why, the shortcuts for the most used commands in emacs involve the Control key instead of the Meta key. (Example: The cursor movements: C-p, C-n, C-f, C-b, C-a, C-e, the cut paste undo C-w, C-y, C-/, the kill-line C-k, the mark C-Space, the search C-s.) Lisp Machine's keyboards fell out of use alone with Lisp Machines. Since the 1990s, the IBM PC keyboard (and its decedents) becomes the most popular and is used by some 98% of personal computers today. The PC keyboard does not have Meta key but have Alt instead. The Alt is placed right beside the space bar, while Control is placed far to the corner.

Emacs did not change its keyboard shortcut bindings to adapt the PC keyboard. Emacs simply remapped its Meta shortcuts to the Alt key by default. (and kept on using the terminology Meta)

The tragedy of the Control/(Alt/Meta) swap made emacs keyboard shortcuts very painful, and the frequent need to press the far-away Control key creates the Emacs Pinky syndrome. (Many emacs-using programer celebrities have injured their hands with emacs. (e.g. Richard Stallman, Jamie Zawinski, Ben Wing), and emacs's Ctrl and Meta combinations are most cited as the major turnoff to potential users among programers)

(For more photos of Lisp Machine's keyboards (all have Control as primary), in roughly chronigical order they are produced, see: Knight keyboard, Symbolics keyboard PN 364000, Symbolics keyboard PN 365407 Rev C (photo by Joey Devilla. Used with permission). )

The Choice Of Keys

The shortcut's key choices are primarily based on first letter of the commands, not based on key position and finger strength or ease of pressing the key. For example, the single char cursor moving shortcuts are scattered around the keyboard with positions that are most difficult to press. (these shortcuts all together accounts for 43% of all commands executed by a keyboard shortcut) Of these, the most frequently used is Ctrl+n, which accounts for 20% of all shortcut calls, but is assigned to the letter n, positioned in the middle of the keyboard, which is one of the most costly key to press. Similarly, the second most used among these is the Ctrl+p, accounting for 16% of all shortcut command calls, is located in a position above the right hand's pinky, also one of the most costly key to press.

(Here we assumes the QWERTY keyboard layout. On the Dvorak layout, it is about as bad.)

Emacs's cursor moving keys on qwerty and dvorak.

Daniel wrote:
That's true.  At the time Guy Steele put together the Emacs default 
key mappings, many people in the target user community (about 20 
people at MIT!) were already using these key bindings.  It would 
have been hard to get the new Emacs bindings accepted by the 
community if they differed for such basic commands.  As you point 
out, anyone using Emacs can very easily change this based on 
their own ergonomic preferences. 

—Daniel Weinreb, 2008-06-01, on comp.emacs newsgroup. Source

Outdated Commands

A significant portion of emacs's major shortcuts (those with Meta+‹key› or Ctrl+‹key›) are mapped to commands that are almost never used today. Some of these occupies the most precious space (Home row with thumb: For example: Meta+s (center-line), Meta+j (indent-new-comment-line), Meta+k (kill-sentence)). Most programer who have used emacs for years never use these commands. For example:

Difficult Keystrokes for Frequently Used Commands

Some commands that are used by every emacs user many times every hour, such as Open, Save, Close, Next Window/Tab, all require multiple keystrokes with the difficult Control key.

No Use of Shift Key

For historical reasons, emacs does not use any keybindings involving the Shift with a letter. (e.g. there's no “Meta+Shift+a”, or “Control+Shift+a”) This is so because in early computing environment, Ctrl+Shift+‹letter› cannot be distinguished from the non-Shift version, due to a practical combination of ASCII, Computer terminal, telnet.

Today, however, employing the Shift key as part of a shortcut with other modifiers is common and convenient. For example, on Mac OS X, Undo and Redo are Cmd+z and Cmd+Shift+z, Save and Save As are Cmd+s and Cmd+Shift+s. On Mac and Windows, moving to next/previous field/window/application often use the Shift key for reversing direction. In text editing on both Mac and Windows, a modifier key with a arrow key will move cursor by word/paragraph, and with Shift down will select them while moving.

Using the Shift key as a reverse operation is very easy to remember, and doesn't take another precious shortcut letter. By not using the Shift key, commands with a logical reverse operation necessarily have to find other key space, and overall making the shortcut set more difficult to remember, or scattered, or more difficult to press.

A Flaw in Keybinding Policy

Any major software, maintains a guide for the developers about the choices of keyboard shortcuts, so that the shortcuts will be consistent. Emacs has this in its Emacs Lisp manual: Elisp Manual: Key-Binding-Conventions.

This guide, indicates that the only key space reserved for users to define, are the function keys F5 to F9, and key stroke sequence starting with Ctrl+c followed by a single letter key.

This is a severe restraint to the utility of customized shortcuts. F5 to F9 are only 6 keys. The key sequence starting with Ctrl+c followed by a letter, is multiple keystrokes and rather a painful choice, and there are only 26 spaces there.

The function keys, F1 to F12, are very good key space for user to define their own shortcuts. The digit key shortcuts, 0 to 9, are also good user space. These keys can be used with any combination of Control, Meta, Shift. For example, a user might define them to insert various templates, headers/footers, a system of customized HTML/XML tags. Or, she might assign them to various special emacs modes such as dired, shell, ftp, email, calendar, calc, *scratch*, make-frame-command (Open a new window), insert signature.

It seems too drastic a policy, to limit user defined keys to only F5 to F9, and key sequence of Ctrl+c followed by a single letter key.

Epilogue: Failure to Change

Today, most commonly used keyboard shortcuts have been somewhat informally standardized. For example, Z X C V is for Undo Cut Copy Paste. O is for Open. S is for Save, Shift-S is for Save As. P is for Print. F is for Find/Search. Tab is for next, Shift tab for previous. These are common conventions today in every application across Microsoft Windows, Macintosh, and Linux desktops.

These shortcut conventions are primarily brought about by Apple Computer Inc's Human interface guidelines and IBM's Common User Access in the 1990s.

In the early 1990s, DOS era software, each application has its own scheme of shortcuts. The following is a excerpt from the Wikipedia article on Common User Access:

CUA was a detailed specification and set strict rules about how applications should look and function. Its aim was in part to bring about harmony between MS-DOS applications, which until then had implemented totally different user interfaces.

Examples:

• In WordPerfect, the command to open a file was [F7], [3].
• In Lotus 1-2-3, a file was opened with [/] (to open the menus), [W] (for Workspace), [R] (for Retrieve).
• In Microsoft Word, a file was opened with [Esc] (to open the menus), [T] (for Transfer), [L] (for Load).
• In WordStar, it was [Ctrl]+[K]+[O].
• In Emacs, a file was opened with [Ctrl]+[x] followed by [Ctrl]+[f] (for find-file).

Some programs used [Esc] to cancel an action, some used it to complete one; WordPerfect used it to repeat a character. Some programs used [End] to go to the end of a line, some used it to complete filling in a form. [F1] was often help but in WordPerfect that was [F3]. [Ins] sometimes toggled between overtype and inserting characters, but some programs used it for “paste”.

Thus, every program had to be learned individually and its complete user interface memorized. It was a sign of expertise to have learned the UIs of dozens of applications, since a novice user facing a new program would find their existing knowledge of a similar application absolutely no use whatsoever.

Commercial software have updated themselves with time (or went extinct), but emacs has not.

If we take a survey of the market share of text editors (including IDEs) among professional programers (as defined by those who make a living by computer programing), then, it is my guess, that emacs from mid 1980s to early 1990s, has more than 50% of market share, but gradually declined. Today, perhaps less than 5% of professional programers use emacs (possibly even below 1%). I think, part of the reason being that emacs has not modernized (not in the sense of being fashionable, but in the sense of keeping with hardware and software changes in the IT industry). The other major reason, is because emacs itself is not a IDE in a modern sense, and most programing development using compiled languages such as Pascal, C, C++, Java, C#, have moved on with IDE platforms integrated with these language's compiler application.

See also: The Modernization of Emacs.

2008-07-15 Addendum: Thanks to Rainer Joswig for some correction about the history of the lisp machine's keyboards. http://groups.google.com/group/comp.lang.lisp/msg/3b3dcdc52f507b02 .

Related essays:

• Emacs's Keyboard Shortcut Layout
• A Ergonomic Keyboard Shortcut Layout For Emacs
• Emacs Command Frequency
• How To Avoid The Emacs Pinky Problem
• Computer keyboards Gallery