Kakoune Language Server Protocol Client

kak-lsp is a Language Server Protocol client for Kakoune implemented in Rust.

Installation

Pre-built binaries

MacOS

Homebrew

brew install ul/kak-lsp/kak-lsp

Manual

curl -O -L https://github.com/ul/kak-lsp/releases/download/v4.0.0/kak-lsp-v4.0.0-x86_64-apple-darwin.tar.gz
tar xzvf kak-lsp-v4.0.0-x86_64-apple-darwin.tar.gz

# replace `~/.local/bin/` with something on your `$PATH`
mv kak-lsp ~/.local/bin/

mkdir -p ~/.config/kak-lsp
mv kak-lsp.toml ~/.config/kak-lsp/

Linux

wget https://github.com/ul/kak-lsp/releases/download/v4.0.0/kak-lsp.x86_64-unknown-linux-musl.tar.gz
tar xzvf kak-lsp.x86_64-unknown-linux-musl.tar.gz

# replace `~/.local/bin/` with something on your `$PATH`
mv kak-lsp ~/.local/bin/

mkdir -p ~/.config/kak-lsp
mv kak-lsp.toml ~/.config/kak-lsp/

FreeBSD

wget https://github.com/ul/kak-lsp/releases/download/v4.0.0/kak-lsp-v4.0.0-x86_64-unknown-freebsd.tar.gz
tar xzvf kak-lsp-v4.0.0-x86_64-unknown-freebsd.tar.gz

# replace `~/.local/bin/` with something on your `$PATH`
mv kak-lsp ~/.local/bin/

mkdir -p ~/.config/kak-lsp
mv kak-lsp.toml ~/.config/kak-lsp/

From the source

Note	ArchLinux users can automate most of the following steps with the kak-lsp-git AUR package.

git clone https://github.com/ul/kak-lsp
cd kak-lsp

cargo build --release

# replace `~/.local/bin/` with something on your `$PATH`
ln -s $PWD/target/release/kak-lsp ~/.local/bin/

mkdir -p ~/.config/kak-lsp
# or just link if you are okay with default config
cp kak-lsp.toml ~/.config/kak-lsp/

Language servers

kak-lsp doesn’t manage installation of language servers, please install them by yourself for the languages you plan to use kak-lsp with. Please consult the How to install servers wiki page for quick installation of language servers supported by kak-lsp out of the box.

Usage

To enable LSP support for configured languages (see the next section) just add following commands to your kakrc:

%sh{kak-lsp --kakoune -s $kak_session}

It adds:

• completions

• lsp-definition command to go to definition, mapped to gd by default

• lsp-hover command to show hover info; to automatically show hover when you move around use lsp-auto-hover-enable; to show hover anchored to hovered position do set global lsp_hover_anchor true

• lsp-references command to find references for a symbol under the main cursor

• lsp-document-symbol command to list current buffer’s symbols

• lsp-diagnostics command to list project-wide diagnostics (current buffer determines project and language to collect diagnostics)

• inline diagnostics highlighting using DiagnosticError and DiagnosticWarning faces; could be disabled with lsp-inline-diagnostics-disable command

• starting new kak-lsp session when Kakoune session begins and stopping it when Kakoune session ends

Note

By default, kak-lsp exits when it doesn’t receive any request from Kakoune during 30 minutes, even if Kakoune session is still up and running. Change server.timeout in kak-lsp.toml to tweak duration, or set it to 0 to disable this behaviour. In any scenario making new request would lead to attempt to spin up server if it is down.

To know which subset of kak-lsp commands is backed by current buffer filetype’s language server use lsp-capabilities command.

Configuration

kak-lsp is configured via configuration file in TOML format. By default kak-lsp tries to read $HOME/.config/kak-lsp/kak-lsp.toml, but you can override it with command-line option --config.

Look into the default kak-lsp.toml in the root of repository, it should be quite self-descriptive.

If you are setting any options to server via cli do not forget to append them to %sh{kak-lsp --kakoune …​} in your kakrc. It’s not needed if you change options in ~/.config/kak-lsp/kak-lsp.toml file.

Please let us know if you have any ideas about how to make default config more sensible.

Troubleshooting

If kak-lsp fails try to put this line in your kakrc after kak-lsp --kakoune invocation:

nop %sh{ (kak-lsp -s $kak_session -vvv ) > /tmp/kak-lsp.log 2>&1 < /dev/null & }

to explicitly start server and enable debug logging. If it will not give enough insights to fix the problem or if the problem is a bug in kak-lsp itself please don’t hesitate to raise an issue.

Note	Some Kakoune plugins could interfere with kak-lsp, particularly completions providers. E.g. racer.kak competes for autocompletion in Rust files.

Versioning

kak-lsp follows SemVer with one notable difference from common practice: we don’t use 0 major version to indicate that product is not yet reached stability. Even for non-stable and not feature-complete product user should be clearly informed about breaking change. Therefore we start with major version 1 and increment it each time when upgrade requires user’s attention.