Typst LSP

A language server for Typst.

Features

• Syntax highlighting, error reporting, code completion, and function signature help
• Compiles to PDF on save (configurable to as-you-type, or can be disabled)
• Experimental formatting using typstfmt

This repo consists of:

• an LSP server, written in Rust
• a corresponding VS Code(ium) extension. The extension is available on the VS Code Marketplace and OpenVSX.

Near future goals

• Improved preview (e.g. built-in PDF viewer, render to image for speed)
• Support for more editors

Building from source

Prerequisites

Install Rust, which comes with cargo. Among other things, cargo is the build tool used for Rust projects.

Building

cargo build --release

Cargo will download and compile Rust dependencies as needed. The --release flag produces and optimized binary. The resulting executable will be at target/release/typst-lsp (with .exe extension on Windows).

Cargo features

Cargo features allow you to customize the build by enabling chunks of code at compile time.

We need an HTTP client to download Typst packages. The client needs a TLS implementation; by default, Rustls is used. If you would like to disable or change this, the following Cargo features are available:

• remote-packages (default): use an HTTP client to download Typst packages
• rustls-tls (default): use Rustls for TLS
• native-tls: use your platform's TLS implementation

For example, the following command will build with native-tls:

cargo build --release --no-default-features --features remote-packages,fontconfig,native-tls

For Linux, native-tls means OpenSSL. You will need to install its headers to compile with native-tls.

Additionally, the fontconfig feature is used to enable minimal support for fontconfig. This is necessary for the LSP to detect fonts in certain Linux distributions, such as NixOS, and is thus enabled by default. If this causes any problems for your distribution, you can disable support for fontconfig by not enabling that feature, such as by compiling with the flags --no-default-features --features remote-packages,rustls-tls.

NOTE: If the LSP fails to find your fonts through fontconfig, try setting (when running the LSP) the FONTCONFIG_FILE environment variable to the absolute path of the fontconfig configuration file specifying your desired font paths. This can happen when using VSCode through Flatpak on distributions such as NixOS, and can lead to some fonts not being detected when compiling your Typst documents. To set the environment variable through Flatpak, you may either use Flatseal or run a command such as below (assuming a --user installation) - make sure to replace the path after FONTCONFIG_FILE with the appropriate one for your system:

# For VSCode:
flatpak override --user --env=FONTCONFIG_FILE=$HOME/.config/fontconfig/conf.d/configfilenamehere.conf com.visualstudio.code

# For VSCodium:
flatpak override --user --env=FONTCONFIG_FILE=$HOME/.config/fontconfig/conf.d/configfilenamehere.conf com.vscodium.codium

Bumping the Typst version

Warning: at time of writing, the Typst API has changed in every release. Until the language is stable, you may need Rust knowledge to address changes in Typst to successfully compile against a new version of Typst.

You will need to modify the Typst dependencies in Cargo.toml. These are at the top of the [dependencies] section, have names starting with typst, and reference git = "https://github.com/typst/typst.git".

If you want to compile against a versioned release of Typst, change the tags to the tag for your desired release. Usually, the tags are named vX.X.X.

If you want to compile against a commit that hasn't been released, replace the tags with revs, and set their values to the Git commit hash. Commit hashes are hexadecimal strings, and have long and short versions that both name the commit. Among other places, a commit's hash can be found at the end of the GitHub URL for that commit.

Development guide

Prerequisites

Install:

• Rust for the LSP itself
• Rust Analyzer an extension for Rust LSP for VS Code
• node for the VS Code extension; it may be easiest to install via fnm

First time setup

1. Clone this repository locally
2. Open it in VS Code; it's needed to run the extension
3. In the editors/vscode subdirectory:
   1. Run npm install to install extension dependencies
   2. Run npm run compile to build the extension
4. Run through the development cycle once to initialize and test everything
5. (Optional: install the dev version of the extension): Press Ctrl+Shift+P, and choose Developer: Install Extension from Location... and choose the directory for the extension, editors/vscode/. There will not be any messages, but the extension can be found in the Extensions @installed list.

Development cycle

1. Make any changes
2. Run cargo install --path .; at present, the VS Code extension just invokes the typst-lsp command to start the LSP, and this command will compile and replace that binary with the latest version
   • If modifying the extension, keep npm run watch running, or npm run compile after changes
3. Press Ctrl+F5 to launch the "Extension Development Host"; if it's already running, invoke "Developer: Reload Window" from the command palette in the Extension Development Host
   • If prompted, choose "Run Extension"
4. Within the Extension Development Host, the extension will be active and ready for testing

Tracing with Jaeger

Jaeger is a tool to visualize tracing data. It shows spans (e.g. a span corresponds to each time a file is opened, each time we calculate semantic tokens, etc.) and associated data (e.g. the URL of the file opened), which provides timing and debugging data.

By default, the LSP does not send data to Jaeger. To enable it:

1. Launch the Jaeger server. The opentelemetry_jaeger crate recommends the following:

   $ docker run -d -p6831:6831/udp -p6832:6832/udp -p16686:16686 -p14268:14268 jaegertracing/all-in-one:latest
   

2. Compile the LSP with the jaeger feature enabled. In the terminal, run:

   $ cargo build --features jaeger
   

   In VS Code, you can use the "Run Extension [Jaeger]" task to launch the extension with Jaeger support.
3. Run the LSP, then eventually close it.
4. From Jaeger, search for traces. It may be best to restrict the search to traces with a minimum length, such as 2 seconds, to hide smaller traces that come from the task sending data to Jaeger.

Installation guide

Visual Studio Code

• Install it from Marketplace.

Neovim

Basic setup

Prerequisites: mason-lspconfig.nvim, mason.nvim and nvim-lspconfig (Optional for advanced users, but required for this guide).

1. Run MasonInstall typst-lsp.
2. Edit your init.lua settings (For more details, you may consult server_configurations.md#typst_lsp):

require'lspconfig'.typst_lsp.setup{
	settings = {
		exportPdf = "onType" -- Choose onType, onSave or never.
        -- serverPath = "" -- Normally, there is no need to uncomment it.
	}
}

3. You may also install typst.vim for more capabilities in nvim.

Additional steps for coc.nvim users

Run CocConfig to edit the settings so that coc.nvim could offer functions such as auto-completion:

{
"languageserver": {
    "typst": {
        "command": "typst-lsp",
        "filetypes": ["typst"]
        }
    }
}

Sublime Text

Follow the configuration instructions for the LSP plugin for Sublime Text.