Dance

Kakoune-inspired key bindings for Visual Studio Code.

Huh?

Dance provides Kakoune-inspired commands and key bindings for Visual Studio Code.

These key bindings are (mostly) compatible with Kakoune's, but are meant to be an addition to Visual Studio Code, rather than an emulation layer on top of it.

Why VS Code, and not Kakoune directly?

• Kakoune is an efficient and lightweight editor with a very small ecosystem. VS Code is an entire IDE with a huge ecosystem and many existing extensions.
• Kakoune is Unix only.

Why Kakoune's key bindings, and not Vim's?

• Whether you prefer Vim, Emacs or Kakoune key bindings is a matter of preference. I, for one, prefer Kakoune's.
• Vim's key bindings are already available to VS Code users.

Why is it merely 'inspired' by Kakoune?

• Unlike VSCodeVim which attempts to emulate Vim, Dance's only goal is to provide VS Code-native commands and key bindings that are inspired by Kakoune.
  • Some features are provided to mimic Kakoune's behavior (e.g. treating positions as coordonates of characters, rather than carets between characters like VS Code), but are optional.
• Kakoune, Vim and VS Code are all fully-fledged text editors; therefore, they have overlapping features. For instance, where VSCodeVim provides its own multi-cursor and command engines to feel more familiar to existing Vim users, Dance leaves multi-cursor mode and editor commands to VS Code entirely.

User Guide

For most commands, the usage is the same as in Kakoune. However, the following changes have been made:

Pipes

• Pipes no longer accept shell commands, but instead accept 'expressions', those being:

  • #<shell command>: Pipes each selection into a shell command (the shell is taken from the terminal.external.exec value).

  • /<pattern>[/<replacement>[/<flags>]: A RegExp literal, as defined in JavaScript. Do note the addition of a replacement, for commands that add or replace text.

  • <JS expression>: A JavaScript expression in which the following variables are available:

    • $: Text of the current selection.
    • $$: Array of the text of all the selections.
    • i: Index of the current selection.

    Depending on the result of the expression, it will be inserted differently:

    • string: Inserted directly.
    • number: Inserted in its string representation.
    • boolean: Inserted as true or false.
    • null: Inserted as null.
    • undefined: Inserted as an empty string.
    • object: Inserted as JSON.
    • Any other type: Leads to an error.

Examples

• /(\d+),(\d+)/$1.$2/g replaces 12,34 into 12.34.
• i + 1 replaces 1,1,1,1,1 into 1,2,3,4,5, assuming that each selection is on a different digit.

Miscellaneous changes

A few changes were made from Kakoune, mostly out of personal preference, and to make the extension integrate better in VS Code. If you disagree with any of these changes, you're welcome to open an issue to discuss it, or to add an option for it by submitting a PR.

• The cursor is not a block, but a line: Dance focuses on selections, and using a line instead of a block makes it obvious whether zero or one characters are selected. Besides, the line-shaped cursor is the default in VS Code.
• Changing the mode will also change the editor.lineNumbers configuration value to on in insert mode, and relative in normal mode.
• The default yank register " maps to the system clipboard.
• There are some additional features not documented here but mentioned in issues and/or in the configuration of the plugin. TODO: document them here.

Troubleshooting

Dance uses the built-in VS Code key bindings, and therefore does not override the type command. However, it sometimes needs access to the type command, in dialogs and register selection, for instance. Consequently, it is not compatible with extensions that always override the type command, such as VSCodeVim; these extensions must therefore be disabled.

Progress

This project is still a WIP. It has gotten better over the years, but may have annoying bugs and lack some features, especially for Kakoune users. Despite this, several users use Dance daily.

In the following list, if a command is implemented, then its extending equivalent (activated while pressing Shift) then likely is implemented as well.

Most (but not all) commands defined in commands are implemented.

• Basic movements:
  • Arrows, hjkl.
  • Move to character, move until character.
  • Move to next word, move to previous word.
• Insert mode:
  • Enter insert mode with a, i, o, and their Alt / Shift equivalents.
  • Exit insert mode with Escape.
• Basic selections:
  • Search in selections.
  • Split in selections.
  • Split selections by lines.
  • Extend selections by taking lines.
  • Trim selections.
• Pipes.
• Object selection.
• Yanking:
  • Yank.
  • Paste.
• Rotate:
  • Rotate selections only.
  • Rotate selections content only.
  • Rotate selections and content.
• Changes:
  • Join.
  • Replace.
  • Delete.
  • Indent.
  • Dedent.
  • Change case.
• Search.
• History:
  • Undo / redo.
  • Forward / backward.
  • Repeat command.
  • Repeat insertion.
• Macros.
• Registers.

Contributing

Plugins

Dance was designed to nicely interopate with other extensions: it does not override the type command, and allows any extension to execute its commands.
It should therefore be possible to create other extensions that work with Dance. If you'd like to add new features to Dance directly, please file an issue.

Bugs and features

There are unfortunately still bugs lurking around features missing. If you'd like to fix bugs or add features, please look at the issues and file one if no other issue matches your request. This will ensure that no two people work on the same feature at the same time, and will be a good place to ask for help in case you want to tackle this yourself.

When contributing, please be mindful of the existing coding conventions and naming.

Your PR will be rebased on top of master in order to keep a clean commit history. Please avoid unnecessary commits (git commit --amend is your friend).

Tests

We recently started adding tests to Dance. Most tests are in test/suite/commands, as plain text files that are separated into several sections.

Tests can be run and debugged in VS Code in the run menu, under "Run Extension Tests".

Sections

Each section has a name, which is any string that has no whitespace.

Except for the first section (implicitly named 0 or root), each section is associated with some transition that consists of several Dance commands to run.

For instance, let's look at the following code:

...

//== 0 > 1
//= dance.select.line
...

//== 1 > 2
//= dance.select.line.extend
...

//== 1 > 3
//= dance.select.line
//= dance.select.line.extend
...

It defines three sections:

• 1, which is reached after executing dance.select.line from section 0.
• 2, which is reached after executing dance.select.line.extend from section 1.
• 3, which is reached after executing dance.select.line and then dance.select.line.extend from section 1.

As you can see, several sections can depend on the same parent section. Do note that sections must be defined in order; that is, a section a cannot depend on a section b if section b is defined after a.

Section content

Each section has content (the ... in the example above). That content is plain text to which one or more selections must be added using a {...} / |{...} syntax, where ... is a number.

{0} represents the anchor of the 1st selection, and |{2} represents the active position of the 3rd selection.

Selections can be given in any order, but must be complete; that is, if a selection 3 is given, then the selections 0, 1, and 2 must be defined at some point too. The anchor can be omitted, and will default to the active position.

Tests generation

For each transition, a test will be generated making sure that executing the corresponding commands will lead to some document with selections at some locations.

Let's look at the following code:

{0}f|{0}oo

//== 0 > 1
//= dance.right
f{0}o|{0}o

//== 1 > 2
//= dance.delete.yank
f{0}o|{0}

The first generated test asserts that calling dance.right in the document foo where f is the main selection leads to a document foo with the first o selected.

The second generated test asserts that calling dance.delete.yank in the document foo where the first o is the main selection leads to a document fo with o selected.

Other features

• Command test files ending with .caret will we run with selectionBehavior == "caret". Otherwise, selectionBehavior == "character" is used.
• Comments can be added by having lines start with "// ".
• When arguments must be passed to the command, JSON can be used, e.g.

  //= {"command": "dance.objects.performSelection", "args": [{"object": "parens", "action": "selectToEnd"}]}
  

• When a command awaits a key press, it can be added after the command, e.g.

  //= dance.select.to.included
  //= type:c