Installation

Yulang is still experimental. The playground is the easiest way to try the language, and the local CLI is mainly for development and regression testing.

Playground

Open the Playground. It runs in the browser with the same standard-library examples used by this documentation.

From source

Clone the repository and use Cargo:

git clone https://github.com/momota1029/yulang.git
cd yulang
cargo test
cargo run -p yulang -- run path/to/file.yu

For local experimentation, cargo run -p yulang -- run path/to/file.yu is the important command (use check instead of run to print inferred types). The web deployment steps below are only needed when updating the hosted playground/docs site.

Published CLI

Install the main CLI with Cargo, then install the embedded standard library:

cargo install yulang
yulang install std

After that, run or check programs directly:

yulang run examples/06_undet_once.yu
yulang check examples/08_types.yu

yulang run prints only program output such as say and println. Use yulang run --print-roots ... when you want to inspect root expression values from the CLI.

The language server ships in the same binary:

yulang server

The Zed extension is not in the public Zed extension registry yet. To use it today, install yulang-zed/ from this repository as a Zed dev extension. The extension starts yulang server when the yulang binary is available in the worktree environment or in ~/.cargo/bin.

The repository is a Rust workspace. The main crates are:

Crate	Purpose
yulang-parser	concrete syntax and operator parsing
yulang-infer	lowering, names, type inference, and core export
yulang-runtime-ir	runtime IR data structures and RuntimeType
yulang-runtime-types	runtime type representation and type-system helpers
yulang-runtime-refine	refine / validate / invariant / hygiene passes
yulang-runtime-lower	core IR → runtime IR lowering
yulang-monomorphize	type graph resolution and monomorphization
yulang-vm	VM compilation and evaluation
yulang-wasm	browser-facing wasm API used by the playground

Web build

The web UI lives under web/:

npm --prefix web install
npm --prefix web run build

For local deployment into a directory:

YULANG_DEPLOY_DIR=/path/to/site npm --prefix web run deploy:dir

The generated site uses / as the playground, /guide/ and /reference/ for the English docs, and /ja/guide/ and /ja/reference/ for the Japanese docs.

Current limitations

• The language and standard library are still changing.
• Filesystem APIs are native-host only; the playground leaves filesystem requests unresolved.
• The wasm bundle embeds standard-library artifacts but still keeps source compilation as a conservative fallback.