e134505b90
* Refactor the `types.rs` types and structures A few changes applied along the way: * Documentation added to most methods and types. * Limits are now stored with the maximum as optional rather than a sentinel u32 value for `None`. * The `Name` type was removed in favor of just using a bare `String`. * The `Extern` prefix in the varaints of `ExternType` has been removed since it was redundant. * Accessors of `ExternType` variants no longer panic, and unwrapping versions were added with "unwrap" in the name. * Fields and methods named `r#type` were renamed to `ty` to avoid requiring a raw identifier to use them. * Remove `fail-fast: false` This was left around since the development of GitHub Actions for wasmtime, but they're no longer needed! * Fix compilation of the test-programs code * Fix compilation of wasmtime-py package * Run rustfmt
wasmtime-rust - Using WebAssembly from Rust
This crate is intended to be an example of how to load WebAssembly files from a
native Rust application. You can always use wasmtime and its family of crates
directly, but the purpose of this crate is to provide an ergonomic macro:
#[wasmtime_rust::wasmtime]
trait WasmMarkdown {
fn render(&mut self, input: &str) -> String;
}
fn main() -> anyhow::Result<()> {
let mut markdown = WasmMarkdown::load_file("markdown.wasm")?;
println!("{}", markdown.render("# Hello, Rust!"));
Ok(())
}
The wasmtime macro defined in the wasmtime-rust crate is placed on a trait
which includes the set of functionality which a wasm module should export. In
this case we're expecting one render function which takes and returns a
string.
The macro expands to a struct with all of the methods on the trait (they must
all be &mut self) and one function called load_file to actually instantiate
the module.
Note that this macro is still in early stages of development, so error messages aren't great yet and all functionality isn't supported yet.
Missing features
Currently if the wasm module imports any symbols outside of the WASI namespace the module will not load. It's intended that support for this will be added soon though!