Yavashark

A new JavaScript engine, currently in development, written in Rust. 🦈

Project Status

The current focus is getting the engine faster. For that multiple POCs have been made. For example string v3, NaN-Boxing value type, the new object model and finally the standalone GC project.

ECMA-262 Compliance

Yavashark currently passes ~81% of the entire test262 suite including intl, temporal, annexB and staging.

Contributing

Contributions to Yavashark are welcome! Whether it's reporting bugs, suggesting features, or contributing code, we appreciate all forms of help in making Yavashark better.

Compiling

Compile the engine via Cargo. Run

cargo build --release # for a binary in target/release/yavashark
cargo run --release # for running the engine directly

Usage

yavashark                      # start the REPL
yavashark script.js            # run a script
yavashark -e 'console.log(1)'  # evaluate code
yavashark -s script.js         # run a script, then stay in the REPL

Option	Description
-e, --eval <CODE>	Evaluate code instead of a script
-s, --repl	Stay in the REPL after the script or --eval
-i, --interpreter	Use the tree-walk interpreter (default)
-b, --bytecode	Use the bytecode VM
-a, --ast	Print the AST
-I, --instructions	Print the bytecode
--profile-out <PATH>	Write a JS profile (needs --features profiler)
--native-profile	Profile the engine itself (needs --features pprof)
--native-profile-out <PATH>	Where to write the native profile

Run yavashark --help for the full list.