[](https://docs.rs/tinywasm) [](https://crates.io/crates/tinywasm) [](./LICENSE-APACHE)
## Why TinyWasm?
- **Tiny**: TinyWasm is designed to be as small as possible without significantly compromising performance or functionality (< 4000 LLOC).
- **Portable**: TinyWasm runs on any platform that Rust can target, including `no_std`, with minimal external dependencies.
- **Safe**: No unsafe code is used in the runtime (`rkyv` which uses unsafe code can be used for serialization, but it is optional).
## Status
As of version `0.3.0`, TinyWasm successfully passes all the WebAssembly 1.0 tests in the [WebAssembly Test Suite](https://github.com/WebAssembly/testsuite). Work on the 2.0 tests is ongoing. This enables TinyWasm to run most WebAssembly programs, including executing TinyWasm itself compiled to WebAssembly (see [examples/wasm-rust.rs](./examples/wasm-rust.rs)). The results of the testsuites are available [here](https://github.com/explodingcamera/tinywasm/tree/main/crates/tinywasm/tests/generated).
The API is still unstable and may change at any time, so you probably don't want to use it in production _yet_. TinyWasm isn't primarily designed for high performance; it focuses more on simplicity, size, and portability. Benchmarks are currently being reworked and will be available again soon.
**Future Development**: The first major version will focus on improving the API and adding support for [WASI](https://wasi.dev/). While doing so, I also want to further simplify and reduce the codebase's size and improve the parser's performance.
## Supported Proposals
| Proposal | Implementation Status | Version |
| -------------------------------------------------------------------------------------------------------------------------- | --------------------- | ------- |
| [**Mutable Globals**](https://github.com/WebAssembly/mutable-global/blob/master/proposals/mutable-global/Overview.md) | Fully implemented | 0.2.0 |
| [**Multi-value**](https://github.com/WebAssembly/spec/blob/master/proposals/multi-value/Overview.md) | Fully implemented | 0.2.0 |
| [**Sign-extension operators**](https://github.com/WebAssembly/spec/blob/master/proposals/sign-extension-ops/Overview.md) | Fully implemented | 0.2.0 |
| [**Bulk Memory Operations**](https://github.com/WebAssembly/spec/blob/master/proposals/bulk-memory-operations/Overview.md) | Fully implemented | 0.4.0 |
| [**Reference Types**](https://github.com/WebAssembly/reference-types/blob/master/proposals/reference-types/Overview.md) | Partially implemented | N/A |
| [**Multiple Memories**](https://github.com/WebAssembly/multi-memory/blob/master/proposals/multi-memory/Overview.md) | Partially implemented | N/A |
| [**Memory64**](https://github.com/WebAssembly/memory64/blob/master/proposals/memory64/Overview.md) | Partially implemented | N/A |
## Usage
TinyWasm can be used through the `tinywasm-cli` CLI tool or as a library in your Rust project. Documentation can be found [here](https://docs.rs/tinywasm).
### Library
```sh
$ cargo add tinywasm
```
### CLI
The CLI is mainly available for testing purposes, but can also be used to run WebAssembly programs.
```sh
$ cargo install tinywasm-cli
$ tinywasm-cli --help
```
## Feature Flags
- **`std`**\
Enables the use of `std` and `std::io` for parsing from files and streams. This is enabled by default.
- **`logging`**\
Enables logging using the `log` crate. This is enabled by default.
- **`parser`**\
Enables the `tinywasm-parser` crate. This is enabled by default.
- **`archive`**\
Enables pre-parsing of archives. This is enabled by default.
With all these features disabled, TinyWasm only depends on `core`, `alloc` ,and `libm` and can be used in `no_std` environments.
Since `libm` is not as performant as the compiler's math intrinsics, it is recommended to use the `std` feature if possible (at least [for now](https://github.com/rust-lang/rfcs/issues/2505)), especially on wasm32 targets.
## Inspiration
Big thanks to the authors of the following projects, which have inspired and influenced TinyWasm:
- [wasmi](https://github.com/wasmi-labs/wasmi) - an efficient and lightweight WebAssembly interpreter that also runs on `no_std` environments
- [wasm3](https://github.com/wasm3/wasm3) - a high performance WebAssembly interpreter written in C
- [wazero](https://wazero.io/) - a zero-dependency WebAssembly interpreter written in go
- [wain](https://github.com/rhysd/wain) - a zero-dependency WebAssembly interpreter written in Rust
I encourage you to check these projects out if you're looking for a more mature and feature-complete WebAssembly interpreter.
## License
Licensed under either of [Apache License, Version 2.0](./LICENSE-APACHE) or [MIT license](./LICENSE-MIT) at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in TinyWasm by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
**Note:** The GitHub repository contains a Submodule (`crates/tinywasm-parser/data`) which is licensed only under the [Apache License, Version 2.0](https://github.com/WebAssembly/spec/blob/main/test/LICENSE). This data is generated from the [WebAssembly Specification](https://github.com/WebAssembly/spec/tree/main/test) and is only used for testing purposes and not included in the final binary.
