Zig Language Server

Zig Language Server, or zls, is a language server for Zig. The Zig wiki states that "The Zig community is decentralized" and "There is no concept of 'official' or 'unofficial'", so instead of calling zls unofficial, and I'm going to call it a cool option, one of many.

Table Of Contents

• Installation
  • Build Options
  • Configuration Options
• Usage
  • VSCode
  • Sublime Text 3
  • Kate
  • Neovim/Vim8
  • Emacs
  • Doom Emacs
• Related Projects
• License

Installation

Installation starts with downloading an official release from the Releases page.

See Downloading and Building ZLS on the Wiki, or the page about using ZLS with Visual Studio Code for a guide to help get zls running in your editor.

Installing binaries

MacOS

You can install the latest release into $HOME/zls using e.g.:

brew install xz
mkdir $HOME/zls && cd $HOME/zls && curl -L https://github.com/zigtools/zls/releases/download/0.1.0/x86_64-macos.tar.xz | tar -xJ --strip-components=1 -C .

Linux

You can install the latest release into $HOME/zls using e.g.:

sudo apt install xz-utils
mkdir $HOME/zls && cd $HOME/zls && curl -L https://github.com/zigtools/zls/releases/download/0.1.0/x86_64-linux.tar.xz | tar -xJ --strip-components=1 -C .

From Source

Building zls is very easy. You will need a build of Zig master to build zls.

git clone --recurse-submodules https://github.com/zigtools/zls
cd zls
zig build -Drelease-safe
zig build config # Configure ZLS

For detailed building instructions, see the Wiki page about Cloning With Git.

Build Options

Option	Type	Default Value	What it Does
-Ddata_version	string (master or 0.7.0)	master	The data file version. This selects the files in the src/data folder that correspond to the Zig version being served.

Configuration Options

You can configure zls by running zls config.
zls will look for a zls.json configuration file in multiple locations with the following priority:

• In the local configuration folder of your OS (as provided by known-folders)
• In the same directory as the executable

The following options are currently available.

Option	Type	Default value	What it Does
enable_snippets	bool	false	Enables snippet completions when the client also supports them.
zig_lib_path	?[]const u8	null	zig library path, e.g. /path/to/zig/lib/zig, used to analyze std library imports.
zig_exe_path	?[]const u8	null	zig executable path, e.g. /path/to/zig/zig, used to run the custom build runner. If null, zig is looked up in PATH. Will be used to infer the zig standard library path if none is provided.
warn_style	bool	false	Enables warnings for style guideline mismatches
build_runner_path	?[]const u8	null	Path to the build_runner.zig file provided by zls. null is equivalent to ${executable_directory}/build_runner.zig
build_runner_cache_path	?[]const u8	null	Path to a directroy that will be used as zig's cache when running zig run build_runner.zig .... null is equivalent to ${KnownFloders.Cache}/zls
enable_semantic_tokens	bool	true	Enables semantic token support when the client also supports it.
operator_completions	bool	true	Enables * and ? operators in completion lists.
skip_std_references	bool	false	When true, skips searching for references in std. Improves lookup speed for functions in user's code. Renaming and go-to-definition will continue to work as is.
include_at_in_builtins	bool	false	Most editors (except Sublime Text, it seems) generate a duplicate @ if a completion starts with it.
max_detail_length	usize	1048576	Completion detail fields are truncated to this length. Decrease if previews lag your editor.

Features

zls supports most language features, including simple type function support, usingnamespace, payload capture type resolution, custom packages and others. Notable language features that are not currently implemented include @cImport as well as most forms of compile time evaluation.

The following LSP features are supported:

• Completions
• Hover
• Goto definition/declaration
• Document symbols
• Find references
• Rename symbol
• Formatting using zig fmt
• Semantic token highlighting (LSP 3.16 proposed feature, implemented by a few clients including VSCode, kak and emacs lsp-mode)

You can install zls using the instuctions for your text editor below:

VSCode

Install the zls-vscode extension from here and provide a path to the build zls executable.

Sublime Text 3

• Install the LSP package from here or via Package Control.
• Add this snippet to LSP's user settings:

{
    "clients": {
        "zig":{
            "command": ["zls"],
            "enabled": true,
            "languageId": "zig",
            "scopes": ["source.zig"],
            "syntaxes": ["Packages/Zig Language/Syntaxes/Zig.tmLanguage"]
        }
    }
}

Kate

• Enable LSP client plugin in Kate settings.
• Add this snippet to LSP client's user settings (e.g. /$HOME/.config/kate/lspclient) (or paste it in LSP client's GUI settings)

{
    "servers": {
        "zig": {
            "command": ["zls"],
            "url": "https://github.com/zigtools/zls",
            "highlightingModeRegex": "^Zig$"
        }
    }
}

Neovim/Vim8

CoC

• Install the CoC engine from here.
• Issue :CocConfig from within your Vim editor, and the following snippet:

{
   "languageserver": {
       "zls" : {
           "command": "command_or_path_to_zls",
           "filetypes": ["zig"]
       }
   }
}

YouCompleteMe

• Install YouCompleteMeFrom here.
• Add these lines to your vimrc:

"ensure zig is a recognized filetype
autocmd BufNewFile,BufRead *.zig set filetype=zig

let g:ycm_language_server = 
  \ [ 
  \{
  \     'name': 'zls',
  \     'filetypes': [ 'zig' ],
  \     'cmdline': [ '/path/to/zls_executable' ]
  \    }
  \ ]

nvim-lspconfig

Requires Nvim 0.5 (HEAD)!

• Install nvim-lspconfig from here.
• Install zig.vim from here.

nvim-lspconfig already ships a configuration for zls. A simple init.vim might look like this:

call plug#begin('~/.config/nvim/plugged')
Plug 'neovim/nvim-lspconfig'
Plug 'nvim-lua/completion-nvim'
Plug 'ziglang/zig.vim'
call plug#end()

:lua << EOF
    local lspconfig = require('lspconfig')

    local on_attach = function(_, bufnr)
        vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')
        require('completion').on_attach()
    end

    local servers = {'zls'}
    for _, lsp in ipairs(servers) do 
        lspconfig[lsp].setup {
            on_attach = on_attach,
        }
    end
EOF

" Set completeopt to have a better completion experience
set completeopt=menuone,noinsert,noselect

" Enable completions as you type
let g:completion_enable_auto_popup = 1

LanguageClient-neovim

• Install the LanguageClient-neovim from here
• Edit your neovim configuration and add zls for zig filetypes:

let g:LanguageClient_serverCommands = {
       \ 'zig': ['~/code/zls/zig-cache/bin/zls'],
       \ }

Emacs

• Install lsp-mode from melpa
• zig mode is also useful

;; Setup lsp-mode as desired.
;; See https://emacs-lsp.github.io/lsp-mode/page/installation/ for more information.
(require 'lsp-mode)

;; Either place zls in your PATH or add the following:
(setq lsp-zig-zls-executable "<path to zls>")

Doom Emacs

• Enable the lsp module
• Install the zig-mode package (add (package! zig-mode) to your packages.el file

(use-package! zig-mode
  :hook ((zig-mode . lsp-deferred))
  :custom (zig-format-on-save nil)
  :config
  (after! lsp-mode
    (add-to-list 'lsp-language-id-configuration '(zig-mode . "zig"))
    (lsp-register-client
      (make-lsp-client
        :new-connection (lsp-stdio-connection "<path to zls>")
        :major-modes '(zig-mode)
        :server-id 'zls))))

Related Projects

• sublime-zig-language by @prime31
  • Supports basic language features
  • Uses data provided by src/data to perform builtin autocompletion
• zig-lsp by @xackus
  • Inspiration for zls
• known-folders by @ziglibs
  • Provides API to access known folders on Linux, Windows and Mac OS

License

MIT