Kakoune for Fuchsia development

Kakoune is a modal text editor inspired by vim. See why-kakoune for why you might want to use it over vim or any other editor or IDE.

Line numbers

Add the following to kakrc to enable relative line numbers (note that this is equivalent to vim when both number and relativenumber are set, meaning that the absolute line number is shown for the line the primary cursor is on).

add-highlighter global/ number-lines -relative

Remove -relative for absolute line numbers.

Plugin manager

plug.kak is a plugin manager inspired by vim-plug. It is the recommended way to install and manage plugins. See the Github README for installation and usage instructions.

The basic workflow to add a plugin is:

  1. Add configuration to kakrc which names and configures the plugin you want to install.
  2. Restart Kakoune in order to reload kakrc.
  3. Run :plug-install to install the plugin.

Indentation and alignment

A recommended setup for indentation and alignment is to use a combination of built-in support for editorconfig and the smarttab.kak plugin. Naturally, this relies on a .editorconfig configuration file being present at or above the root of the Fuchsia checkout. Add the following lines to kakrc and then install the smarttab.kak plugin:

plug "andreyorst/smarttab.kak" defer smarttab %{
    set-option global softtabstop 4

hook global BufOpenFile .* %{
hook global BufNewFile .* %{

Note that backspace always removes one indentation worth of spaces in indentation context, and the value of softtabstop only affects how many spaces are deleted in alignment context. A value of 4 is the recommended default; other alternatives are:

  • %opt(indentwidth) to use the value of indentwidth, or
  • a very large number such that all alignment spaces are deleted with a single input of backspace.

LSP client

kak-lsp is a LSP (Language Server Protocol) client written in Rust. See the Github README for installation instructions.

The default kak-lsp.toml runs clangd for C and C++, gopls for Go, and rustup which rust-analyzer for Rust. Edit the TOML config file to make any necessary changes.

At minimum, the following configuration line should be added to enter LSP mode through which all LSP functionality can be accessed.

map global user l %{:enter-user-mode lsp<ret>} -docstring "LSP mode"

Filetype-specific configuration


The first release version to include FIDL support is v2022.08.11. Run kak -version to verify that you are running this or a more recent version. If you are running an older version, the alternatives are:

  1. Compile from source; or
  2. Save a copy of fidl.kak anywhere and source it from kakrc. For example, if it is saved next to kakrc, it can be sourced by:

    source "%val(config)/fidl.kak"

    This works because %val(config) expands to the path where kakrc can be found.

FIDL filetype support includes syntax highlighting and indentation. The only indentation behavior present by the auto-formatter that is not implemented is alignment of colons for table and union fields.