witgen

witgen is a library to help you generate wit definitions in a wit file for WebAssembly. Using this lib in addition to wit-bindgen will help you to import/export types and functions from/to wasm module.

Getting started

• Put this dependency in your Cargo.toml

witgen = "0.3"

• Install cargo witgen CLI

$ cargo install cargo-witgen

Examples

• Into your Rust code:

use witgen::witgen;

#[witgen]
struct TestStruct {
    inner: String,
}

#[witgen]
enum TestEnum {
    Unit,
    Number(u64),
    String(String),
}

#[witgen]
fn test(other: Vec<u8>, test_struct: TestStruct, other_enum: TestEnum) -> Result<(String, i64), String> {
    Ok((String::from("test"), 0i64))
}

• Then you can launch (at the root of your package):

$ cargo witgen generate

• It will generate a witgen.wit file at the root of your package:

record TestStruct {
    inner: string
}

variant TestEnum {
    Unit,
	Number(u64),
	String(string),
}

test : function(other: list <u8>, test_struct: TestStruct, other_enum: TestEnum) -> expected<tuple<string, s64>>

Development

It's a very minimal version, it doesn't already support all kinds of types but the main used are supported. I made it to easily generate .wit files for my need. Feel free to create issues or pull-requests if you need something. I will be happy to help you !