Awesome Emacs Keymap (emacs-mcx)

Emacs emulation for Visual Studio Code

• Emacs-like cursor movements and editing commands
• Customizable meta key assignment (alt, ESC, ctrl+[, or command on macOS)
• Search behavior like Emacs' isearch
• Compatibility with VSCode's built-in multi cursor feature
• Kill-ring integrated with the system clipboard
• Mark-ring
• Prefix argument
• Rectangle commands
• Text/position/rectangle registers
• Sexp operations (with ParEdit commands)

It's inspired by Emacs Keymap by hiro-sun and its forks such as Emacs Friendly Keymap by Sebastian Zaha, Emacs Keymap Improved by rkwan94, and Emacs Friendly Keybindings (Neon) by NotKyon, but totally revamped and improved for better feature coverage, Emacs emulation, and usability (also getting rid of some bugs).

FAQ/Tips

The cursor cannot be moved on the find widget as the widget closes with movement keys.

It's an intended design that simulates the original Emacs' behavior. You can disable it with emacs-mcx.cursorMoveOnFindWidget option described below. See #137 for the details about this topic.

i-search (C-s) is initialized with the currently selected string and the previous search is removed.

Setting editor.find.seedSearchStringFromSelection as "never" can change this behavior. It makes the find widget work similarly to Emacs.

Refs:

• The official doc about editor.find.seedSearchStringFromSelection setting
• The GitHub issue where we discuss about it

I want to customize the META key (ESC, ctrl+[, alt, or Command (⌘) key on macOS).

You can configure the key to be used as a META prefix with the following settings.

• emacs-mcx.useMetaPrefixAlt (true by default)
• emacs-mcx.useMetaPrefixEscape
• emacs-mcx.useMetaPrefixCtrlLeftBracket
• emacs-mcx.useMetaPrefixMacCmd

Read the extension settings section below for more details.

I want to use keyboard macro

Check out Keyboard Macro Beta by tshino (tshino.kb-macro) and its keybindings.

The extension has been broken!

Try the Developer: Reinstall Extension... command from the command palette to reinstall the extension. I fixed a problem by this way somehow.

I find a bug. I want a feature X to be implemented. I have a question.

Post a bug report or a feature request to GitHub Issues.

Extension settings

This extension has some custom settings named with a prefix emacs-mcx. You can configure those settings. (See this page to know how to change the settings.)

Configurable options of this extension are the followings.

emacs-mcx.moveBeginningOfLineBehavior

Determines the behavior of the move-beginning-of-line command. If set as 'vscode', it works as VSCode's native Home key behavior. If set as 'emacs', it works as the original Emacs' move-beginning-of-line.

emacs-mcx.moveEndOfLineBehavior

Determines the behavior of the move-end-of-line command. If set as 'vscode', it works as VSCode's native End key behavior. If set as 'emacs', it works as the original Emacs' move-end-of-line.

emacs-mcx.scrollUpCommandBehavior

Determines the behavior of the scroll-up-command command. If set as 'vscode', it works as VSCode's native Page Down key behavior. If set as 'emacs', it works as the original Emacs' scroll-up-command.

emacs-mcx.scrollDownCommandBehavior

Determines the behavior of the scroll-down-command command. If set as 'vscode', it works as VSCode's native Page Up key behavior. If set as 'emacs', it works as the original Emacs' scroll-down-command.

emacs-mcx.strictEmacsMove (deprecated)

If set as true, all emacs-mcx.moveBeginningOfLineBehavior, emacs-mcx.moveEndOfLineBehavior, emacs-mcx.scrollUpCommandBehavior, and emacs-mcx.scrollDownCommandBehavior are set to 'emacs'.

emacs-mcx.keepCursorInVisibleRange

If set as true, the cursor is kept in the visible range when scrolling up or down like Emacs.

emacs-mcx.emacsLikeTab

If set as true, tab key works as the Emacs' tab-to-tab-stop command.

emacs-mcx.useMetaPrefixEscape

If set as true, Escape key works as the Meta prefix like original Emacs. If set as false, Escape key works as cancel, the VSCode's native behavior. For example, if set as true, M-f (forward-word) can be issued by both alt+f and escape f.

The only exception is the commands which begin with M-g (M-g g, M-g n, M-g p). It is because VSCode can handle only up to two key strokes as the key bindings. So, as the special case, Escape g works as follows.

Command	Desc
Escape g	Jump to line (command palette)

emacs-mcx.useMetaPrefixCtrlLeftBracket

If set as true, ctrl+[ works as the Meta prefix like original Emacs.

emacs-mcx.useMetaPrefixAlt

If set as true, alt key (option (⌥) key on macOS) works as the Meta prefix.

emacs-mcx.useMetaPrefixMacCmd

If set as true, Command (⌘) key works as the Meta prefix on macOS. This option only works on macOS.

emacs-mcx.killRingMax

Configures the maximum number of kill ring entries. The default is 60.

emacs-mcx.killWholeLine

This simulates the original Emacs' kill-whole-line variable. The default is false.

emacs-mcx.cursorMoveOnFindWidget

If set to true, cursor move commands of this extension such as C-f and C-b are disabled when the find widget is focused, to allow the widget to keep open and the cursor to move on it.

emacs-mcx.enableOverridingTypeCommand

Prefix arguments do not work on character inputs with IMEs by default and you can set this config to true in order to enable it. Note that this config makes use of VSCode API's type command under the hood and can cause problems in some cases.

• If you are using IME, text input may sometimes fail.
• If another extension that also uses the type command is installed, an error occurs (See microsoft/vscode#13441).

emacs-mcx.enableDigitArgument

Indicates whether M-<digit> (the emacs-mcx.digitArgument command) is enabled. Set false when M-<digit> conflicts with some other necessary commands. See #1208 for the background.

emacs-mcx.lineMoveVisual

When true, line-move moves point by visual lines (same as an Emacs variable line-move-visual).

emacs-mcx.paredit.parentheses

Key-value pairs of parentheses like the following example to be used in the ParEdit commands.

{
  "[": "]",
  "(": ")",
  "{": "}"
}

emacs-mcx.debug.*

Configurations for debugging.

'when' clause context

This extension provides some contexts that you can refer to in "when" clauses of your keybindings.json.

emacs-mcx.inMarkMode

boolean

This indicates whether mark-mode is enabled.

emacs-mcx.acceptingArgument

boolean

This indicates the editor is accepting argument input following C-u.

emacs-mcx.prefixArgumentExists (experimental)

boolean

This indicates if a prefix argument exists. Use this boolean context to check the existence of a prefix argument, instead of using emacs-mcx.prefixArgument with null check.

emacs-mcx.prefixArgument (experimental)

number | undefined

This is a currently input prefix argument.

Keybindings

Alt key is mapped to the Meta prefix (M) by default and you can configure for Escape, ctrl+[, or Command (⌘) key (macOS only) to work as it with the settings above.

Move commands

Command	Prefix argument	Desc
C-f	✓	Move forward (forward-char)
C-b	✓	Move backward (backward-char)
C-n	✓	Move to the next line (next-line)
C-p	✓	Move to the previous line (previous-line)
C-a	✓	Move to the beginning of line (move-beginning-of-line)
C-e	✓	Move to the end of line (move-end-of-line)
M-f	✓	Move forward by one word unit (forward-word)
M-b	✓	Move backward by one word unit (backward-word)
C-<right>, M-<right>	✓	This command (right-word) behaves like M-f
C-<left>, M-<left>	✓	This command (left-word) behaves like M-b
M-m		Move (forward or back) to the first non-whitespace character on the current line (back-to-indentation)
C-v	✓	Scroll down by one screen unit (scroll-up-command)
M-v	✓	Scroll up by one screen unit (scroll-down-command)
M-S-[ (M-{ with US keyboard), C-<up>	✓	Move back to previous paragraph beginning (backward-paragraph)
M-S-] (M-} with US keyboard), C-<down>	✓	Move forward to next paragraph end (forward-paragraph)
M-S-, (M-< with US keyboard)		Move to the top of the buffer (beginning-of-buffer)
M-S-. (M-> with US keyboard)		Move to the end of the buffer (end-of-buffer)
M-g g (M-g M-g)	✓	Read a number n and move point to the beginning of line number n (goto-line)
M-g n (M-g M-n, C-x ` )		Jump to next error
M-g p (M-g M-p)		Jump to previous error
C-l		Center screen on current line (recenter-top-bottom)

Search Commands

Command	Desc
C-s	Incremental search forward (isearch-forward).
C-r	Incremental search backward (isearch-backward).
C-M-s	Begin incremental regexp search (isearch-forward-regexp).
C-M-r	Begin reverse incremental regexp search (isearch-backward-regexp).
M-S-5 (M-% with US keyboard)	Replace (query-replace)
C-M-S-5 (C-M-% with US keyboard)	Replace with regexp (query-replace-regexp)
C-M-n	Add selection to next find match
C-M-p	Add selection to previous find match
M-s o	Open Quick Search, which is like Emacs' occur command.
M-c	Toggles the case sensitivity of the find widget.

Edit commands

Command	Prefix argument	Desc
C-d	✓	Delete right (DEL)
C-h	✓	Delete left (BACKSPACE)
M-\	✓	Delete spaces and tabs around point (delete-horizontal-space).
C-x C-o		Delete blank lines around (delete-blank-lines)
C-t	✓	Transpose characters (transpose-chars).
C-x C-t	✓	Transpose lines (transpose-lines).
M-S-6 (M-^ with US keyboard)		join two lines cleanly (delete-indentation)
M-d	✓	Kill word (kill-word)
M-Bksp	✓	Kill word left (backward-kill-word)
C-k	✓	Kill from the current cursor to the end of line (kill-line)
C-S-Bksp		Kill whole line (kill-whole-line)
C-w		Kill region
M-w		Copy region to kill ring
C-y	✓	Yank
M-y	✓	Yank pop
C-c y		Browse kill ring
C-o		Open line
C-j	✓	New line
C-m	✓	New line
C-x h		Select All
C-x u, C-/, C-S-- (C-_ with US keyboard)		Undo
C-;		Toggle line comment in and out
M-;		Toggle region comment in and out
C-x C-l (M-l)		Convert to lower case (On the Emacs' original behavior, C-x C-l and M-l are assigned to the different functionalities. However, this extension assigns these keys to the same emacs-mcx.transformToLowercase command which calls editor.action.transformToLowercase command internally and works similarly to both the original Emacs' functionalities based on the context. Upper case and title case (below) are same)
C-x C-u (M-u)		Convert to upper case
M-c		Convert to title case

Mark Commands

Command	Desc
C-SPC, C-S-2 (C-@ with US keyboard)	Set the mark at point, and activate it (set-mark-command).
C-SPC C-SPC	Set the mark, pushing it onto the mark ring, without activating it.
C-u C-SPC	Move point to where the mark was, and restore the mark from the ring of former marks.
C-x C-x	Set the mark at point, and activate it; then move point where the mark used to be (exchange-point-and-mark).

See this page and this page about the mark and the mark ring.

Intellisense

Command	Desc
C-M-i, M-TAB, M-/, C-'	Trigger suggest. These keybindings call editor.action.triggerSuggest command, alternating Emacs' completion-at-point or dabbrev-expand

Text registers

Command	Desc
C-x r s r	Copy region into register r (copy-to-register).
C-x r i r	Insert text from register r (insert-register).

See this page about the text registers.

Position registers

Command	Desc
C-x r SPC r	Record the position of point and the current buffer in register r (point-to-register).
C-x r j r	Jump to the position and buffer saved in register r (jump-to-register).

Rectangles

Command	Desc
C-x r k	Kill the text of the region-rectangle, saving its contents as the last killed rectangle (kill-rectangle).
C-x r M-w	Save the text of the region-rectangle as the last killed rectangle (copy-rectangle-as-kill).
C-x r d	Delete the text of the region-rectangle (delete-rectangle).
C-x r y	Yank the last killed rectangle with its upper left corner at point (yank-rectangle).
C-x r p	Replace last kill ring to each line of rectangle if the kill ring top only contains one line.
C-x r o	Insert blank space to fill the space of the region-rectangle (open-rectangle).
C-x r c	Clear the region-rectangle by replacing all of its contents with spaces (clear-rectangle).
C-x r t	Replace rectangle contents with string on each line (string-rectangle).
C-x SPC	Toggle Rectangle Mark mode (rectangle-mark-mode).

Rectangle Registers

Command	Desc
C-x r r r	Copy the region-rectangle into register r (copy-rectangle-to-register). With prefix argument, delete it as well.
C-x r i r	Insert the rectangle stored in register r (if it contains a rectangle) (insert-register).

Other Commands

Command	Desc
C-g (ESC)	Quit
ESC ESC ESC	Quit (keyboard-escape-quit, but this extension does not distinguish it from C-g)
C-' (M-/)	IntelliSense Suggestion
M-x	Open command palette
C-M-SPC	Toggle SideBar visibility
C-x z	Toggle Zen Mode
C-x C-c	Close window (save-buffers-kill-terminal)

File Commands

Command	Desc
C-x C-f	QuickOpen a file (Tips: This extension assigns C-x C-f to the VSCode's native quick file navigation. If you prefer more Emacs-like behavior, The "File Browser" extension by Bodil Stokke (bodil.file-browser) may help.)
C-x C-s	Save
C-x C-w	Save as
C-x s	Save all files
C-x C-n	Open new window

Tab / Buffer Manipulation Commands

Command	Desc
C-x b	Switch to another open buffer
C-x k	Close current tab (buffer)
C-x 0	Close editors in the current group.
C-x 1	Close editors in other (split) group.
C-x 2	Split editor horizontal
C-x 3	Split editor vertical
C-x 4	Toggle split layout (vertical to horizontal)
C-x o	Focus other split editor
C-x LEFT	Select the previous tab (previous-buffer).
C-x RIGHT	Select the next tab (next-buffer).

Prefix argument

See https://www.gnu.org/software/emacs/manual/html_node/emacs/Arguments.html for detail

Command	Desc
C-u	universal-argument
M-<number>	digit-argument
M--	negative-argument

sexp

Command	Prefix argument	Desc
C-M-f	✓	Move forward over a balanced expression (forward-sexp)
C-M-b	✓	Move backward over a balanced expression (backward-sexp)
C-M-S-2 (C-M-@ with US keyboard)	✓	Set mark after end of following balanced expression (mark-sexp). This does not move point.
C-M-k	✓	Kill balanced expression forward (kill-sexp)
C-M-Bksp	✓	Kill balanced expression backward (backward-kill-sexp)
C-S-k	✓	Kill a line as if with kill-line, but respecting delimiters. (paredit-kill)

This extension makes use of paredit.js to provide sexp functionalities. Thank you for this great library.

Looking up identifiers

Command	Desc
M-.	Find definitions of an identifier (xref-find-definitions). It's just bound to VSCode's "Go to Definition" (editor.action.revealDefinition).
M-,	Go back to where you previously invoked M-. and friends (xref-go-back). It's just bound to VSCode's "Go Back" (workbench.action.navigateBack).
C-M-,	Go forward to where you previously invoked M-, (xref-go-forward). It's just bound to VSCode's "Go Forward" (workbench.action.navigateForward).
M-S-/ (M-? with US keyboard)	Find references of an identifier (xref-find-references). It's just bound to VSCode's "References: Find All References" (references-view.findReferences).

Other commands/APIs

emacs-mcx.executeCommandWithPrefixArgument

This command calls another command with the prefix argument. This is mainly for extension developers who want to make the extensions collaborative with this extension's prefix argument. See the issue #1146 for the discussion about it.

For example, if you define the keybinding below,

• C-x e will call the command foo with the argument {}.
• C-u C-x e will call the command foo with the argument { prefixArgument: 4 }.

{
  "key": "ctrl+x e",
  "command": "emacs-mcx.executeCommandWithPrefixArgument",
  "args": {
    "command": "foo"
  }
}

You can pass the arguments to the target command as below. In this case,

• C-x e will call the command foo with the argument { baz: 42 }.
• C-u C-x e will call the command foo with the argument { prefixArgument: 4, baz: 42 }.

{
  "key": "ctrl+x e",
  "command": "emacs-mcx.executeCommandWithPrefixArgument",
  "args": {
    "command": "foo",
    "args": {
      "baz": 42
    }
  }
}

You can change the key name of the prefix argument.

{
  "key": "ctrl+x e",
  "command": "emacs-mcx.executeCommandWithPrefixArgument",
  "args": {
    "command": "foo",
    "prefixArgumentKey": "repeat"
  }
}

• C-x e will call the command foo with the argument {}.
• C-u C-x e will call the command foo with the argument { repeat: 4 }.

Overriding the prefix argument

When you define a keybinding for emacs-mcx.* commands, you can override the prefix argument by specifying the prefixArgument in the keybinding's arguments.

For example:

{
  "key": "alt+shift+y",
  "command": "emacs-mcx.yankPop",
  "args": {
    "prefixArgument": -1
  }
}

With this keybinding, you can call emacs-mcx.yankPop command with a prefix argument -1 by pressing alt+shift+y.

Conflicts with default key bindings

• ctrl+d: editor.action.addSelectionToNextFindMatch => Use ctrl+alt+n instead;
• ctrl+g: workbench.action.gotoLine => Use alt+g g instead;
• ctrl+b: workbench.action.toggleSidebarVisibility => Use ctrl+alt+space instead;
• ctrl+j: workbench.action.togglePanel => Use ctrl+x j instead;
• ctrl+space: toggleSuggestionDetails, editor.action.triggerSuggest => Use ctrl+' instead;
• ctrl+x: editor.action.clipboardCutAction => Use ctrl+w instead;
• ctrl+v: editor.action.clipboardPasteAction => Use ctrl+y instead;
• ctrl+k: editor.debug.action.showDebugHover, editor.action.trimTrailingWhitespace, editor.action.showHover, editor.action.removeCommentLine, editor.action.addCommentLine, editor.action.openDeclarationToTheSide;
• ctrl+k z: workbench.action.toggleZenMode => Use ctrl+x z instead;
• ctrl+y: redo;
• ctrl+m: editor.action.toggleTabFocusMode;
• ctrl+/: editor.action.commentLine => Use ctrl+; instead;
• ctrl+p & ctrl+e: workbench.action.quickOpen => Use ctrl+x b instead;
• ctrl+p: workbench.action.quickOpenNavigateNext => Use ctrl+n instead.
• ctrl+o: workbench.action.files.openFileFolder;

Contributions/Development

Your contributions are very welcome!

Please see DEVELOPMENT.md about development of this extension.