Kakoune Language Server Protocol Client
kak-lsp is a Language Server Protocol client for Kakoune implemented in Rust.
MacOS
Homebrew
brew install kak-lsp/kak-lsp/kak-lsp
Manual
curl -O -L https://github.com/kak-lsp/kak-lsp/releases/download/v14.2.0/kak-lsp-v14.2.0-x86_64-apple-darwin.tar.gz
tar xzvf kak-lsp-v14.2.0-x86_64-apple-darwin.tar.gz
# replace `~/.local/bin/` with something on your `$PATH`
mv kak-lsp ~/.local/bin/
# optional: if you want to use specific language servers
mkdir -p ~/.config/kak-lsp
mv kak-lsp.toml ~/.config/kak-lsp/
Linux
Package managers
Arch Linux: pacman -S kak-lsp
or AUR/kak-lsp-git
Void Linux: xbps-install -S kak-lsp
Fedora Copr: sudo dnf copr enable atim/kakoune -y && sudo dnf install kak-lsp
Others
wget https://github.com/kak-lsp/kak-lsp/releases/download/v14.2.0/kak-lsp-v14.2.0-x86_64-unknown-linux-musl.tar.gz
tar xzvf kak-lsp-v14.2.0-x86_64-unknown-linux-musl.tar.gz
# replace `~/.local/bin/` with something on your `$PATH`
mv kak-lsp ~/.local/bin/
# optional: if you want to use specific language servers
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
# this installs the kak-lsp binary to ~/.cargo/bin, which must be in your `$PATH`
cargo install --locked --force --path .
# optional: if you want to use specific language servers
mkdir -p ~/.config/kak-lsp
cp kak-lsp.toml ~/.config/kak-lsp/
If you don’t mind using a plugin manager, you can install kak-lsp via plug.kak. Add this code to your kakrc
:
plug "kak-lsp/kak-lsp" do %{
cargo install --locked --force --path .
# optional: if you want to use specific language servers
mkdir -p ~/.config/kak-lsp
cp -n kak-lsp.toml ~/.config/kak-lsp/
}
cargo install
will install the kak-lsp
binary to ~/.cargo/bin
, which must be in your $PATH
. Alternatively, you can replace cargo install
with cargo build --release && ln -sf $PWD/target/release/kak-lsp ~/.local/bin/
where ~/.local/bin/
can be replaced with 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.
To enable LSP support for configured languages (see Configuration) just add the following commands to your kakrc
:
eval %sh{kak-lsp --kakoune -s $kak_session} # Not needed if you load it with plug.kak.
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} # Not needed if you load it with plug.kak.
hook global WinSetOption filetype=(rust|python|go|javascript|typescript|c|cpp) %{
lsp-enable-window
}
There are three default mappings in goto-mode: gd
(lsp-definition
), gy
(lsp-type-definition
) and gr
(lsp-references
). You can override them in your kakrc after this plugin is loaded.
Here are additional recommended mappings. See below for the meaning of each command.
map global user l %{:enter-user-mode lsp<ret>} -docstring "LSP mode"
map global insert <tab> '<a-;>:try lsp-snippets-select-next-placeholders catch %{ execute-keys -with-hooks <lt>tab> }<ret>' -docstring 'Select next snippet placeholder'
map global object a '<a-semicolon>lsp-object<ret>' -docstring 'LSP any symbol'
map global object <a-a> '<a-semicolon>lsp-object<ret>' -docstring 'LSP any symbol'
map global object e '<a-semicolon>lsp-object Function Method<ret>' -docstring 'LSP function or method'
map global object k '<a-semicolon>lsp-object Class Interface Struct<ret>' -docstring 'LSP class interface or struct'
map global object d '<a-semicolon>lsp-diagnostic-object --include-warnings<ret>' -docstring 'LSP errors and warnings'
map global object D '<a-semicolon>lsp-diagnostic-object<ret>' -docstring 'LSP errors'
Note | 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 to the README.asciidoc revision tagged with the version you use or the README.asciidoc from the release archive. |
If you have followed above steps you get
completions
lsp-definition
command to go to definition, mapped to gd
by default
lsp-hover
command to show hover info (including relevant diagnostics when available) in the info box.
lsp-hover-buffer
command to show the same in a scratch buffer.
to automatically show hover when you move around, use lsp-auto-hover-enable
to show hover anchored to hovered position, use set global lsp_hover_anchor true
to exclude diagnostics, use 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, mapped to gy
by default
lsp-implementation
command to find implementations for the symbol under the main cursor
lsp-references
command to find references to the symbol under the main cursor, mapped to gr
by default
for the previous five commands, the *goto*
buffer has filetype lsp-goto
, so you can press <ret>
on a line or use the lsp-jump
command
lsp-find-error
command to jump to the next or previous error in the current file
lsp-selection-range
command to quickly select interesting ranges around selections.
lsp-selection-range-select
to navigate ranges fetched by lsp-selection-range
.
lsp-next-location
and lsp-previous-location
to jump to the next or previous location listed in a buffer with the lsp-goto
filetype. These also work for buffers *grep*
, *lint*
and *make*
lsp-highlight-references
command to select (unless run in a hook context) all references to the symbol under the main cursor in the current buffer and highlight them with the Reference
face (which is equal to the MatchingChar
face by default)
lsp-document-symbol
command to list the current buffer’s symbols
lsp-goto-document-symbol
command to jump to one of the 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 has filetype lsp-goto
so you can press <ret>
on a line or use the lsp-jump
command
lsp-diagnostics
command to list project-wide diagnostics (current buffer determines project and language to collect diagnostics for)
*diagnostics*
buffer has filetype lsp-goto
so you can press <ret>
on a line or use the lsp-jump
command
lsp-incoming-calls
and lsp-outgoing-calls
commands to list callers and callees of the function at the cursor.
*callers*
and *callees*
buffers have filetype lsp-goto
so you can press <ret>
on a line or use the lsp-jump
command
lsp-signature-help
command to show signature information of the function under the main cursor
To automatically show signature information in insert mode, use lsp-auto-signature-help-enable
.
inline diagnostics highlighting using the DiagnosticError
, DiagnosticHint
, DiagnosticInfo
and DiagnosticWarning
faces; can be disabled with lsp-inline-diagnostics-disable
command
flags in the left margin on lines with errors or other diagnostics; can be disabled with lsp-diagnostic-lines-disable
command
for lines with code lenses, a >
flag which can be customized via the lsp_code_lens_sign
option
lsp-code-lens
command to execute a code lens from the current selection
commands lsp-inlay-code-lenses-enable
and lsp-inlay-code-lenses-disable
to toggle rendering of code lenses.
You can change the code lenses' face with set-face global InlayCodeLens <face>
.
lsp-formatting
command to format current buffer, according to the tabstop
and lsp_insert_spaces
options
lsp-formatting-sync
command to format current buffer synchronously, suitable for use with BufWritePre
hook:
hook global WinSetOption filetype=rust %{
hook window BufWritePre .* lsp-formatting-sync
}
lsp-object
command to select adjacent or surrounding syntax tree nodes in [object mode](https://github.com/mawww/kakoune/blob/master/doc/pages/modes.asciidoc#object-mode)
lsp-diagnostic-object
does something similar but for inline diagnostics.
lsp-next-symbol
and lsp-previous-symbol
command to go to the buffer’s next and current/previous symbol.
lsp-hover-next-symbol
and lsp-hover-previous-symbol
to show hover of the buffer’s next and current/previous symbol.
lsp-rename <new_name>
and lsp-rename-prompt
commands to rename the symbol under the main cursor.
An hourglass character (⌛) in the modeline whenever the language server indicates it’s busy.
To customize this behavior, override lsp-handle-progress
.
To implement this, kak-lsp adds %opt{lsp_modeline} ` to the left of your global `modelinefmt
at load time.
If lsp_auto_show_code_actions
is true
, a lightbulb (💡) in the modeline whenever code actions are available at the main cursor position
To customize the lightbulb, you can override lsp-show-code-actions
and lsp-hide-code-actions
lsp-code-actions
to open a menu to choose a code action to run
To customize the menu, you can override lsp-perform-code-action
lsp-code-action
to run the code action matching the given pattern.
lsp-code-action-sync
to synchronously run that code action, suitable for use in a BufWritePre
hook.
lsp_diagnostic_error_count
, lsp_diagnostic_hint_count
, lsp_diagnostic_info_count
and lsp_diagnostic_warning_count
options which contain the number of diagnostics of the respective level 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
lsp-connect
to handle language server responses with a user-defined command. This command is experimental and will likely see further changes.
lsp-execute-command
command to execute server-specific commands (listed by lsp-capabilities
).
Commands starting with either of ccls-
, clangd-
, ejdtls-
, texlab-
or rust-analyzer-
, that provide server specific features.
Note | By default, kak-lsp exits when it doesn’t receive any request from Kakoune for 30 minutes, even if the Kakoune session is still up and running. Change server.timeout in kak-lsp.toml to tweak this duration, or set it to 0 to disable this behavior. In any scenario, a new request would spin up a fresh server if it is down. |
lsp
user mode with the following default mappings:
Binding | Command |
---|---|
a | lsp-code-actions |
c | lsp-capabilities |
d | lsp-definition |
e | lsp-diagnostics |
f | lsp-formatting |
h | lsp-hover |
i | lsp-implementation |
j | lsp-outgoing-calls |
k | lsp-incoming-calls |
l | lsp-code-lens |
r | lsp-references |
R | lsp-rename-prompt |
s | lsp-goto-document-symbol |
S | lsp-document-symbol |
o | lsp-workspace-symbol-incr |
n | lsp-find-error |
p | lsp-find-error --previous |
v | lsp-selection-range |
y | lsp-type-definition |
9 | lsp-hover-previous-function |
0 | lsp-hover-next-function |
& | lsp-highlight-references |
( | lsp-previous-function |
) | lsp-next-function |
[ | lsp-hover-previous-symbol |
] | lsp-hover-next-symbol |
{ | lsp-previous-symbol |
} | lsp-next-symbol |
To know which subset of kak-lsp commands is backed by the current buffer’s filetype’s language server use lsp-capabilities
command.
kak-lsp itself has configuration, but it also adds configuration options to Kakoune that affect the Kakoune integration.
kak-lsp is configured via a configuration file in TOML format. By default kak-lsp tries to read $XDG_CONFIG_HOME/kak-lsp/kak-lsp.toml
(which defaults to ~/.config/kak-lsp/kak-lsp.toml
) but you can override it with command-line option --config
. Look into the default kak-lsp.toml
, it should be quite self-explanatory. If you don’t need to change configuration then feel free to skip copying it anywhere as the default configuration is embedded into the kak-lsp binary.
Important: The configuration file does not extend the default configuration, but rather overrides it. This means that if you want to customize any of the configuration, you must copy the entire default configuration and then edit it.
In the language section of kak-lsp.toml
, the roots
parameter is a list of file globs. Whenever your editor session wants to send an LSP request, the first glob that matches a file in any of the current buffer’s parent directories will cause kak-lsp
to set the project root to that parent directory.
You can define an environment variable like KAK_LSP_PROJECT_ROOT_RUST=/my/project
to always use /my/project
as root for Rust files inside /my/project
. Substitute RUST
with another language ID to do the same for other file types.
The environment variable KAK_LSP_FORCE_PROJECT_ROOT=/my/project
will make kak-lsp
always use /my/project
as project root, even for files outside this directory. This avoids starting separate language servers for files outside /my/project
, and ensures that your language server is aware of your project’s build configuration even when navigating library code.
If you are setting any server options 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
.
Please let us know if you have any ideas about how to make the default config more sensible.
Many servers accept configuration options that are not part of the LSP spec. The TOML table [language.<filetype>.settings]
holds those configuration options. It has the same structure as the corresponding fragments from VSCode’s settings.json
. For example:
[language.go]
...
settings_section = "gopls"
[language.go.settings.gopls]
"formatting.gofumpt" = true
During server initialization, kak-lsp sends the section specified by settings_section
; in this case {"formatting.gofumpt":true}
. Whenever you change the Kakoune option lsp_config
, the same section is sent via workspace/didChangeConfiguration
. Additionally, kak-lsp will send arbitrary sections that are requested by the server in workspace/configuration
.
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
, lsp_diagnostic_line_hint_sign
, lsp_diagnostic_line_info_sign
, and lsp_diagnostic_line_warning_sign
(str): When using lsp-diagnostic-lines-enable
and the language server detects an error or another diagnostic, kak-lsp will add a flag to the left-most column of the window, using this string and one of the corresponding faces LineFlagError
, LineFlagHint
, LineFlagInfo
or LineFlagWarning
.
lsp_hover_anchor
(bool): When using lsp-hover
or lsp-auto-hover-enable
, if this option is true
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. Default is 20.
lsp_hover_insert_mode_trigger
(str): This option is set to a Kakoune command. When using lsp-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 using lsp-formatting
, if this option is true
, kak-lsp will ask the language server to indent with spaces rather than tabs.
lsp_auto_highlight_references
(bool): If this option is true
then lsp-highlight-references
is executed every time the user pauses in normal mode.
lsp_auto_show_code_actions
(bool): If this option is true
then lsp-code-actions
is executed every time the user pauses in normal mode.
lsp_config
(str): This is a TOML string of the same format as kak-lsp.toml
, except it currently only supports one kind of configuration value:
[language.<filetype>.settings]
: this works just like the static configuration of the same name in kak-lsp.toml
, see the section about server-specific configuration. This will override the static configuration of the given language.
For example, you can toggle an option dynamically with a command like this:
set-option global lsp_config %{
[language.go.settings.gopls]
"formatting.gofumpt" = true
}
Inlay hints are a feature proposed for LSP 3.17 to 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
:
lsp-inlay-hints-enable global
You can change the hints' face 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
, using the semantic_tokens.faces
array, for example:
[semantic_tokens]
faces = [
{face="const_variable_declaration", token="variable", modifiers=["constant", "declaration"]},
]
where face
is the face that will be applied in Kakoune (you’ll want to define these in your theme/config), token
is the token’s name as reported by the language server (see lsp-capabilities
) and modifiers
is an array of modifier names (also reported by the language server). modifiers
may be omitted, but token
and face
are required.
You may create any arbitrary number of definitions with permutations between the token names and modifiers reported by the server. For an entry to match a token, all the entry’s modifiers must exist on the token. However, the token may have additional modifiers not assigned in the config entry.kak-lsp
will find the most specific matching configuration to apply, where specificity is defined as the number of matching modifiers. If multiple matching entries have the same number of modifiers, the one that was defined last in the configuration wins.
Example:
Assuming the following configuration,
[semantic_tokens]
faces = [
{face="const_variable_declaration", token="variable", modifiers=["constant","declaration"]},
{face="const_variable", token="variable", modifiers=["constant"]},
{face="variable", token="variable"},
]
kak-lsp
will perform these mappings:
Token | Modifiers | Face | Comment |
---|---|---|---|
variable | constant , declaration | const_variable_declaration | First entry matches with 2 modifiers. |
variable | constant | const_variable | First and second entry match with 1 modifier, second wins. |
variable | declaration | variable | Only third entry matches. First entry doesn’t match, because constant is missing. |
variable | variable | Third entry matches. | |
function | No entries match and no face is applied. |
kak-lsp supports showing diagnostics inline after their respective line, but this behavior can be somewhat buggy and must be enabled explicitly:
lsp-inlay-diagnostics-enable global
kak-lsp shows some additional information provided by the language server in an info box. This information includes documentation for the token under the cursor (lsp-hover
) and documentation for completion candidates. In both cases, the Language Server Protocol allows for both plain text and Markdown, and most servers do implement Markdown.
To make use of Markdown, kak-lsp transpiles it into Kakoune’s markup language, utilizing various faces for styling. These faces all default to the Information
face, to ensure that the text in the info box works with any color scheme.
To enable Markdown highlighting, define some of the following faces in your theme or kakrc
:
Face | Usage |
---|---|
InfoDefault | The default text color. You’ll likely want to leave this at the default Information . |
InfoBlock | The face used for code blocks. Language specific syntax highlighting for code blocks is not supported. |
InfoBlockQuote | The face used for block quotes. The > Markdown syntax is still rendered. |
InfoBullet | The face used to highlight the list symbol for both ordered and unordered lists. For list items' text, InfoDefault is used. |
InfoHeader | The face used for headings. There is currently no distinction between different heading levels. |
InfoLink | The face used to highlight link titles. Maybe some classic blue+u for this one? |
InfoLinkMono | This face is assigned to inline code spans within link titles, such as in the following Markdown snippet. Here, the word [the `format` function](https://example.com) |
InfoMono | The face used for inline code spans (backtick strings). |
InfoRule | The face used for horizontal lines (rules). |
InfoDiagnosticError | Used for error messages in the diagnostics inside hover info. This defaults to Kakoune’s built-in Error face. |
InfoDiagnosticHint | Used for hints in the diagnostics inside hover info. |
InfoDiagnosticInformation | Used for informational messages in the diagnostics inside hover info. |
InfoDiagnosticWarning | Used for warnings in the diagnostics inside hover info. |
For convenience, here is a snippet to paste into your theme/config:
face global InfoDefault Information
face global InfoBlock Information
face global InfoBlockQuote Information
face global InfoBullet Information
face global InfoHeader Information
face global InfoLink Information
face global InfoLinkMono Information
face global InfoMono Information
face global InfoRule Information
face global InfoDiagnosticError Information
face global InfoDiagnosticHint Information
face global InfoDiagnosticInformation Information
face global InfoDiagnosticWarning Information
Current limitations of this feature are:
Language specific syntax highlighting for code blocks is not supported.
For hyperlinks, only their title (the pretty name) is shown.
The original syntax for headings is retained to visualize their level.
Snippets are completions that come with placeholders ("tabstops") in the places you likely want to insert text (for example function call arguments). The placeholders are highlighted with the two faces SnippetsNextPlaceholders
and SnippetsOtherPlaceholders
.
The lsp-snippets-select-next-placeholders
command allows to jump to the next tabstop (like function call arguments). The suggested mapping uses <tab>
(see Configure mappings). Here’s a way to bind it to <c-n>
instead (might need to hide the completion menu with Kakoune’s <c-o>
command):
map global insert <c-n> '<a-;>:lsp-snippets-select-next-placeholders<ret>' -docstring 'Select next snippet placeholder'
hook global InsertCompletionShow .* %{
unmap global insert <c-n> '<a-;>:lsp-snippets-select-next-placeholders<ret>'
}
hook global InsertCompletionHide .* %{
map global insert <c-n> '<a-;>:lsp-snippets-select-next-placeholders<ret>' -docstring 'Select next snippet placeholder'
}
Snippet support can be disabled by setting snippet_support = false
at the top level of the config.
kak-lsp works best with UTF-8 documents.
Position.character
interpretationThe LSP spec says that column offsets (Position.character
) are to be interpreted as UTF-16 code units. Many servers violate the spec. Please refer to microsoft/language-server-protocol#376 for some background.
kak-lsp adheres to the spec but will prefer UTF-8 offsets if the server advertises support for UTF-8 offsets via client capabilities general.positionEncodings
or clangd protocol extension.
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 does not give enough insight to fix the problem or if the problem is a bug in kak-lsp itself please don’t hesitate to raise an issue.
Please also try to reproduce the issue with a minimal configuration. Sometimes the problem occurs only with specific settings in your ~/.config/kak-lsp/kak-lsp.toml
and/or ~/.config/kak/
. Use this command to start Kakoune with kak-lsp enabled, both with pristine settings.
HOME=$(mktemp -d) kak -e '
eval %sh{kak-lsp --kakoune -s $kak_session}
set global lsp_cmd "kak-lsp -s %val{session} -vvvv --log /tmp/kak-lsp.log"
lsp-enable'
Note | Some Kakoune plugins could interfere with kak-lsp, particularly completions providers. E.g. racer.kak competes for autocompletion in Rust files. |
For troubleshooting crashes, you might like to run kak-lsp outside of Kakoune.
To do this:
Before launching Kakoune, run kak-lsp with an arbitrary session ID (here foobar
):
kak-lsp -s foobar
In a second terminal, run Kakoune with the same session ID:
kak -s foobar
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.
Author: kak-lsp
Source: https://github.com/kak-lsp/kak-lsp/
License: Unlicense, Unknown licenses found