Facilitating high-level interactions between Wasm modules and JavaScript
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Alex Crichton c915870526 Remove temporary object allocation
When returning a ptr/length for allocations and such wasm-bindgen's
generated JS would previously return an array with two elements. It
turns out this doesn't optimize well in all engines! (See #1031). It
looks like we can optimize the array destructuring a bit more, but this
is all generated code which doesn't need to be too readable so we can
also remove the temporary allocation entirely and just pass the second
element of this array through a global instead of the return value.

Closes #1031
2018-11-13 08:10:05 -08:00
.cargo Start running CI tests on Rust beta 2018-09-25 10:36:28 -07:00
crates Remove temporary object allocation 2018-11-13 08:10:05 -08:00
examples Bump to 0.2.28 2018-11-12 09:28:01 -08:00
guide Rename host_binding to final 2018-11-09 08:00:41 -08:00
releases Add a template for release announcements 2018-06-19 12:05:52 -07:00
src Don't worry about descriptive strings for malloc errors 2018-11-09 12:19:48 -08:00
tests Merge pull request #1019 from alexcrichton/rfc-5 2018-11-12 10:59:46 -06:00
.appveyor.yml Merge pull request #989 from alexcrichton/stable-ci 2018-10-28 14:14:49 -07:00
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.travis.yml Fix a bug in coalescing types with GC 2018-10-30 15:45:21 -07:00
build.rs Implement AsRef<JsValue> for Closure<T> 2018-09-06 14:46:59 -07:00
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wasm-bindgen

Facilitating high-level interactions between wasm modules and JavaScript.

Build Status Build status API Documentation on docs.rs

Import JavaScript things into Rust and export Rust things to JavaScript.

extern crate wasm_bindgen;
use wasm_bindgen::prelude::*;

// Import the `window.alert` function from the Web.
#[wasm_bindgen]
extern {
    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-bindgen only generates bindings and glue for the JavaScript imports you actually use and Rust functionality that you export. For example, importing and using the document.querySelector method doesn't cause Node.prototype.appendChild or window.alert to 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 "host 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! 📚

API Docs

License

This project is licensed under either of

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.