Installation

Yulang is still experimental. If you want to follow the guide locally, install the release CLI first, then run a tiny .yu file. The playground remains the fastest way to try examples without installing anything.

Binary release

Install the release archive for your OS. The binary contains the embedded standard library and writes it to the user library directory on first use:

curl -fsSL https://yulang.momota.pw/install.sh | sh -s -- --version v0.1.0-alpha.9

The shell installer adds ~/.yulang/bin to the relevant shell profile if it is not already on PATH; restart the terminal before running yulang. Pass --no-modify-path if you want to manage PATH yourself.

On Windows:

Invoke-WebRequest https://yulang.momota.pw/install.ps1 -OutFile install.ps1
powershell -ExecutionPolicy Bypass -File .\install.ps1 -Version v0.1.0-alpha.9

The PowerShell installer adds the install bin directory to the user PATH. Use -NoModifyPath to skip that step.

Check that a file runs

Create hello.yu:

cat > hello.yu <<'YU'
println "hello from Yulang"
1 + 2
YU
yulang run --print-roots hello.yu

Expected output:

hello from Yulang
run roots [(), 3]

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. Use check instead of run to print inferred types:

yulang check hello.yu

For one-line experiments, run also accepts source text from -e, explicit stdin with -, or an implicit pipe:

yulang run -e "(each 1..20 + each 1..20).list.say"
echo "1 + 2" | yulang run --print-roots
echo "1" | yulang run --print-roots -

A bare yulang run in an interactive terminal still prints usage instead of waiting for input.

To remove a release install:

curl -fsSL https://yulang.momota.pw/uninstall.sh | sh

On Windows:

Invoke-WebRequest https://yulang.momota.pw/uninstall.ps1 -OutFile uninstall.ps1
powershell -ExecutionPolicy Bypass -File .\uninstall.ps1

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 source-tree experimentation, cargo run -p yulang -- run path/to/file.yu is the important command. The web deployment steps below are only needed when updating the hosted playground/docs site.

The CLI caches compiler artifacts under the user cache root. See Cache for .yucu, .yuir, .yuvm, and the route labels printed by --runtime-phase-timings.

The language server ships in the same binary:

yulang server

The Zed extension starts yulang server from the installed yulang binary. It searches the worktree environment, ~/.yulang/bin, and ~/.cargo/bin. The source copy is kept under yulang-zed/ and mirrored to the separate extension repository.

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.