kak-lsp is a Language Server Protocol client for Kakoune implemented in Rust.
Note
|
kak-lsp.toml destination in all described installation methods is just an example.
Also, kak-lsp doesn’t read the configuration file from the current working directory or binary’s dir by default.
Please consult Configuring kak-lsp to figure out where does kak-lsp expect kak-lsp.toml
to be in your environment and how to specify a custom path to it.
However, if you don’t need to change configuration then feel free to skip copying it anywhere as the default configuration is embedded into kak-lsp binary.
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curl -O -L https://github.com/kak-lsp/kak-lsp/releases/download/v9.0.0/kak-lsp-v9.0.0-x86_64-apple-darwin.tar.gz tar xzvf kak-lsp-v9.0.0-x86_64-apple-darwin.tar.gz # replace `~/.local/bin/` with something on your `$PATH` mv kak-lsp ~/.local/bin/ mkdir -p ~/.config/kak-lsp mv kak-lsp.toml ~/.config/kak-lsp/
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Arch Linux:
pacman -S kak-lsp
or AUR/kak-lsp-git -
Void Linux:
xbps-install -S kak-lsp
-
Fedora Copr:
sudo dnf copr enable atim/kakoune -y && sudo dnf install kak-lsp
wget https://github.com/kak-lsp/kak-lsp/releases/download/v9.0.0/kak-lsp-v9.0.0-x86_64-unknown-linux-musl.tar.gz tar xzvf kak-lsp-v9.0.0-x86_64-unknown-linux-musl.tar.gz # replace `~/.local/bin/` with something on your `$PATH` mv kak-lsp ~/.local/bin/ mkdir -p ~/.config/kak-lsp mv kak-lsp.toml ~/.config/kak-lsp/
Generally, you need the latest stable version of Rust to build kak-lsp.
git clone https://github.com/kak-lsp/kak-lsp cd kak-lsp cargo install --locked --force --path . # replace `~/.config` with OS-specific dir as described at https://docs.rs/dirs/2.0.1/dirs/fn.config_dir.html mkdir -p ~/.config/kak-lsp # or just link if you are okay with default config cp kak-lsp.toml ~/.config/kak-lsp/
If you don’t mind using plugin manager, you can install kak-lsp
with plug.kak. Add this code to your kakrc
:
plug "kak-lsp/kak-lsp" do %{ cargo install --locked --force --path . }
You can replace cargo install
with ln -sf target/release/kak-lsp ~/.local/bin/
where ~/.local/bin/
can be replaced to something in your $PATH
.
Examples of configuration with plug.kak can be found at Wiki.
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.
Note
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Contents below corresponds to the master branch HEAD and could be slightly out-of-sync with the version installed from pre-built binaries. The most common case is new commands being in a pre-release testing stage. Please refer README.asciidoc revision tagged with version you use or README.asciidoc from the release archive (included starting from version 5.10.0). |
To enable LSP support for configured languages (see the next section) just add the following
commands to your kakrc
:
eval %sh{kak-lsp --kakoune -s $kak_session} lsp-enable
A bit more involved but recommended way is to enable kak-lsp only for specific filetypes you need
via lsp-enable-window
, e.g.:
eval %sh{kak-lsp --kakoune -s $kak_session} hook global WinSetOption filetype=(rust|python|go|javascript|typescript|c|cpp) %{ lsp-enable-window }
Either way you get:
-
completions
-
lsp-definition
command to go to definition, mapped togd
by default -
lsp-hover
command to show hover info (including relevant diagnostics when available)-
to automatically show hover when you move around use
lsp-auto-hover-enable
-
to show hover anchored to hovered position do
set global lsp_hover_anchor true
-
to exclude diagnostics do
set-option global lsp_show_hover_format 'printf %s "${lsp_info}"'
-
-
lsp-declaration
command to jump to the declaration of the symbol under the main cursor -
lsp-definition
command to jump to the definition of the symbol under the main cursor -
lsp-type-definition
command to jump to the definition of the type of the symbol under the main cursor -
lsp-implementation
command to find implementations for a symbol under the main cursor -
lsp-references
command to find references for a symbol under the main cursor, mapped togr
by default-
for the previous five commands,
*goto*
buffer hasgrep
filetype so you can press<ret>
on a line or use thegrep-jump
command
-
-
lsp-find-error
command to jump to the next or previous error in the file-
lsp-references-previous-match
andlsp-references-next-match
to navigate between references
-
-
lsp-highlight-references
command to highlight references in current buffer for a symbol under the main cursor withReference
face (which is equal toMatchingChar
face by default) -
lsp-document-symbol
command to list current buffer’s symbols -
lsp-workspace-symbol
command to list project-wide symbols matching the query -
lsp-workspace-symbol-incr
command to incrementally list project-wide symbols matching the query-
*symbols*
buffer hasgrep
filetype so you can press<ret>
on a line or use thegrep-jump
command -
lsp-symbols-previous-match
andlsp-symbols-next-match
to navigate between symbols
-
-
lsp-diagnostics
command to list project-wide diagnostics (current buffer determines project and language to collect diagnostics)-
*diagnostics*
buffer hasmake
filetype so you can press<ret>
on a line or use themake-jump
command
-
-
inline diagnostics highlighting using
DiagnosticError
andDiagnosticWarning
faces; could be disabled withlsp-inline-diagnostics-disable
command -
flags in the left margin on lines with errors or warnings; could be disabled with
lsp-diagnostic-lines-disable
command -
lsp-formatting
command to format current buffer, according to thetabstop
andlsp_insert_spaces
options -
lsp-formatting-sync
command to format current buffer synchronously, suitable for use withBufWritePre
hook:
hook global WinSetOption filetype=rust %{ hook window BufWritePre .* lsp-formatting-sync }
-
lsp-rename <new_name>
andlsp-rename-prompt
commands to rename the symbol under the main cursor. -
lsp-code-actions
command to open a menu with code actions available for the current main cursor position -
lsp_diagnostic_error_count
andlsp_diagnostic_warning_count
options which contains number of diagnostics errors and warnings published for the current buffer. For example, you can put it into your modeline to see at a glance if there are errors in the current file -
starting new kak-lsp session when Kakoune session begins and stopping it when Kakoune session ends
Note
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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.
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-
lsp
user mode. The following example mapping gives you access to the shortcuts from below table after typing,l
.
map global user l %{: enter-user-mode lsp<ret>} -docstring "LSP mode"
Binding | Command |
---|---|
a |
lsp-code-actions |
c |
lsp-capabilities |
d |
lsp-definition |
e |
lsp-diagnostics |
f |
lsp-formatting |
h |
lsp-hover |
i |
lsp-implementation |
r |
lsp-references |
R |
lsp-rename-prompt |
s |
lsp-signature-help |
S |
lsp-document-symbol |
o |
lsp-workspace-symbol-incr |
n |
lsp-find-error |
p |
lsp-find-error --previous |
y |
lsp-type-definition |
& |
lsp-highlight-references |
To know which subset of kak-lsp commands is backed by current buffer filetype’s language server use
lsp-capabilities
command.
All commands are also represented as subcommands of umbrella lsp
command if you prefer this style.
For example, you can use lsp references
instead of lsp-references
.
kak-lsp itself has configuration, but it also adds configuration options to Kakoune that affect the Kakoune integration.
kak-lsp is configured via configuration file in TOML format. By
default kak-lsp tries to read kak-lsp/kak-lsp.toml
under OS-specific config dir as described here,
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.
The only example which is not covered by default kak-lsp.toml
is setting initialization options
for a language server. It’s done like this:
[language.go.initialization_options] formatTool = "gofmt"
Important: The configuration file does not extend the default configuration, but rather overwrites it. This means that if you want to customize any of the configuration, you must copy the entire default configuration and then edit it.
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.
kak-lsp’s Kakoune integration declares the following options:
-
lsp_completion_trigger
(str): This option is set to a Kakoune command, which is executed every time the user pauses in insert mode. If the command succeeds, kak-lsp will send a completion request to the language server. -
lsp_diagnostic_line_error_sign
(str): When usinglsp-diagnostic-lines-enable
and the language server detects an error, kak-lsp will add a flag to the left-most column of the window, using this string and theLineFlagErrors
face. -
lsp_diagnostic_line_warning_sign
(str): When usinglsp-diagnostic-lines-enable
and the language server detects an warning, kak-lsp will add a flag to the left-most column of the window, using this string and theLineFlagErrors
face. -
lsp_hover_anchor
(bool): When usinglsp-hover
orlsp-auto-hover-enable
, if this option istrue
then the hover information will be displayed next to the active selection. Otherwise, the information will be displayed in a box in the lower-right corner. -
lsp_hover_max_lines
(int): If greater than 0 then limit rendered hover information to the given number of lines. -
lsp_hover_insert_mode_trigger
(str): This option is set to a Kakoune command. When usinglsp-auto-hover-insert-mode-enable
, this command is executed every time the user pauses in insert mode. If the command succeeds, kak-lsp will send a hover-information request for the text selected by the command. -
lsp_insert_spaces
(bool): When usinglsp-formatting
, if this option istrue
, kak-lsp will ask the language server to indent with spaces rather than tabs. -
lsp_auto_highlight_references
(bool): If this option istrue
thenlsp-highlight-references
is executed every time user pauses in normal mode. -
lsp_server_configuration
(str-to-str-map): At startup, and when this option is modified, kak-lsp will send its contents to the language server in aworkspace/DidChangeConfiguration
notification. Some languages servers allow dynamic configuration in this way. See below for more information about this option. -
lsp_server_initialization_options
(str-to-str-map): Wheninitialize
request is sent to the language server kak-lsp will ask Kakoune for this option value in the buffer which provoked start of the language server. If value is non-empty then it will overrideinitialization_options
set for the buffer’s filetype inkak-lsp.toml
. See below for more information about this option.
The lsp_server_configuration
and lsp_server_initialization_options
options are unusual, since
the language server wants deeply-nested JSON objects, which are hard to represent in Kakoune. If a
language server’s documentation says it wants a structure like this:
{ "settings": { "rust": { "clippy_preference": "on" } } }
…you can achieve the same thing in Kakoune with:
set-option global lsp_server_configuration rust.clippy_preference="on"
That is, the keys of the lsp_server_configuration
option are a .
-delimited path of JSON objects. For implementation reasons, the values use TOML serialisation rules rather than JSON rules, but they’re pretty much the same thing for strings, numbers and booleans, which are the most common configuration types.
Inlay hints are a feature supported by rust-analyzer, which show inferred types, parameter names in function calls, and the types of chained calls inline in the code. To enable support for it in kak-lsp, add the following to your kakrc
:
hook global WinSetOption filetype=rust %{ hook window -group rust-inlay-hints BufReload .* rust-analyzer-inlay-hints hook window -group rust-inlay-hints NormalIdle .* rust-analyzer-inlay-hints hook window -group rust-inlay-hints InsertIdle .* rust-analyzer-inlay-hints hook -once -always window WinSetOption filetype=.* %{ remove-hooks window rust-inlay-hints } }
You can change the face of the hints with set-face global InlayHint <face>
.
kak-lsp supports the semanticTokens feature for semantic highlighting. If the language server supports it, you can enable it with:
hook global WinSetOption filetype=<language> %{ hook window -group semantic-tokens BufReload .* lsp-semantic-tokens hook window -group semantic-tokens NormalIdle .* lsp-semantic-tokens hook window -group semantic-tokens InsertIdle .* lsp-semantic-tokens hook -once -always window WinSetOption filetype=.* %{ remove-hooks window semantic-tokens } }
The faces used for semantic tokens and modifiers can be modified in kak-lsp.toml
, under the semantic_tokens
and semantic_token_modifiers
sections. The modifiers are used first if available, and then the main token type is used if no modifier face is specified.
kak-lsp supports showing diagnostics inline after their respective line, but this behaviour can be somewhat buggy and must be enabled explicitly:
lsp-inlay-diagnostics-enable global
kak-lsp has experimental support for snippets. It is enabled by setting snippet_support = true
at the top level of the config.
It uses the two faces SnippetsNextPlaceholders
and SnippetsOtherPlaceholders
, you may want to customize those.
To properly use snippets, you’ll probably want something like this:
def -hidden insert-c-n %{ try %{ lsp-snippets-select-next-placeholders exec '<a-;>d' } catch %{ exec -with-hooks '<c-n>' } } map global insert <c-n> "<a-;>: insert-c-n<ret>"
This maps <c-n>
to select the next placeholder if there is one, and otherwise executes <c-n>
as normal
Currently, kak-lsp doesn’t conform to the spec regarding the interpretation of Position.character
.
LSP spec says that
A position inside a document (see Position definition below) is expressed as a zero-based line and character offset. The offsets are based on a UTF-16 string representation. So a string of the form
a𐐀b
the character offset of the charactera
is 0, the character offset of𐐀
is 1 and the character offset ofb
is 3 since𐐀
is represented using two code units in UTF-16.
However, kak-lsp treats Position.character
as an offset in UTF-8 code points by default.
Fortunately, it appears to produce the same result within the Basic Multilingual Plane (BMP) which
includes a lot of characters.
Unfortunately, many language servers violate the spec as well, and in an inconsistent manner. Please refer microsoft/language-server-protocol#376 for more information. There are two main types of violations we met in the wild:
1) Using UTF-8 code points, just like kak-lsp does. Those should work well with kak-lsp for characters outside BMP out of the box.
2) Using UTF-8 code units (bytes), just like Kakoune does. Those are supported by kak-lsp but
require adding offset_encoding = "utf-8"
to language server configuration in kak-lsp.toml
.
If kak-lsp fails try to put this line in your kakrc
after kak-lsp --kakoune
invocation:
set global lsp_cmd "kak-lsp -s %val{session} -vvv --log /tmp/kak-lsp.log"
to 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
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Some Kakoune plugins could interfere with kak-lsp, particularly completions providers.
E.g. racer.kak competes for autocompletion in Rust files.
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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.