3cc30843e3
This commit is the second, and hopefully last massive, refactor for using WebIDL bindings internally in `wasm-bindgen`. This commit actually fully executes on the task at hand, moving `wasm-bindgen` to internally using WebIDL bindings throughout its code generation, anyref passes, etc. This actually fixes a number of issues that have existed in the anyref pass for some time now! The main changes here are to basically remove the usage of `Descriptor` from generating JS bindings. Instead two new types are introduced: `NonstandardIncoming` and `NonstandardOutgoing` which are bindings lists used for incoming/outgoing bindings. These mirror the standard terminology and literally have variants which are the standard values. All `Descriptor` types are now mapped into lists of incoming/outgoing bindings and used for process in wasm-bindgen. All JS generation has been refactored and updated to now process these lists of bindings instead of the previous `Descriptor`. In other words this commit takes `js2rust.rs` and `rust2js.rs` and first splits them in two. Interpretation of `Descriptor` and what to do for conversions is in the binding selection modules. The actual generation of JS from the binding selection is now performed by `incoming.rs` and `outgoing.rs`. To boot this also deduplicates all the code between the argument handling of `js2rust.rs` and return value handling of `rust2js.rs`. This means that to implement a new binding you only need to implement it one place and it's implemented for free in the other! This commit is not the end of the story though. I would like to add a mdoe to `wasm-bindgen` that literally emits a WebIDL bindings section. That's left for a third (and hopefully final) refactoring which is also intended to optimize generated JS for bindings. This commit currently loses the optimization where an imported is hooked up by value directly whenever a shim isn't needed. It's planned that the next refactoring to emit a webidl binding section that can be added back in. It shouldn't be too too hard hopefully since all the scaffolding is in place now. cc #1524
wasm-bindgen
Facilitating high-level interactions between Wasm modules and JavaScript.
Guide | API Docs | Contributing | Chat
Built with 🦀🕸 by The Rust and WebAssembly Working Group
Example
Import JavaScript things into Rust and export Rust things to JavaScript.
use wasm_bindgen::prelude::*;
// Import the `window.alert` function from the Web.
#[wasm_bindgen]
extern "C" {
fn alert(s: &str);
}
// Export a `greet` function from Rust to JavaScript, that alerts a
// hello message.
#[wasm_bindgen]
pub fn greet(name: &str) {
alert(&format!("Hello, {}!", name));
}
Use exported Rust things from JavaScript with ECMAScript modules!
import { greet } from "./hello_world";
greet("World!");
Features
-
Lightweight. Only pay for what you use.
wasm-bindgenonly generates bindings and glue for the JavaScript imports you actually use and Rust functionality that you export. For example, importing and using thedocument.querySelectormethod doesn't causeNode.prototype.appendChildorwindow.alertto be included in the bindings as well. -
ECMAScript modules. Just import WebAssembly modules the same way you would import JavaScript modules. Future compatible with WebAssembly modules and ECMAScript modules integration.
-
Designed with the "Web IDL bindings" proposal in mind. Eventually, there won't be any JavaScript shims between Rust-generated wasm functions and native DOM methods. Because the wasm functions are statically type checked, some of those native methods' dynamic type checks should become unnecessary, promising to unlock even-faster-than-JavaScript DOM access.
Guide
📚 Read the wasm-bindgen guide here! 📚
You can find general documentation about using Rust and WebAssembly together here.
API Docs
License
This project is licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Contribution
See the "Contributing" section of the guide for information on
hacking on wasm-bindgen!
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.