Facilitating high-level interactions between Wasm modules and JavaScript
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Alex Crichton 9daa11592a Remove Module node from the backend AST
This is a roundabout way to say that this addresses the last comment on #23,
namely if you only use the `console` submodule from `web_sys` it doesn't
actually link correctly!

The problem here has to do with codegen units and the compiler. The compiler
will create a codegen unit for each `mod` in the source code. If a codegen unit
isn't actually used, then the codegen unit is removed from the final link step.
This causes problems for web-sys where the JSON description of our program was
part of the main CGU but not in each submodule, so when submodules were only
used the descriptor program in the main CGU was not included.

The fix in this commit is to instead generate a descriptor program in the
submodule itself instead of leaving it in the main CGU. By removing the `Module`
node in the AST this naturally happens as the descriptor is only generated in
the same module as all other associated items.
2018-09-17 13:50:26 -07:00
.cargo Don't run the test runner in release mode 2018-08-04 08:22:47 -07:00
crates Remove Module node from the backend AST 2018-09-17 13:50:26 -07:00
examples Use Cell instead of RefCell 2018-09-13 03:38:22 +03:00
guide Fix dependencies sections for web-sys in guide 2018-09-14 14:05:04 -07:00
releases Add a template for release announcements 2018-06-19 12:05:52 -07:00
src doc: Add nightly feature hint for closures 2018-09-11 07:06:21 +02:00
tests Add docs and remove typecheck from variadic attribute 2018-09-01 13:55:35 +01:00
.appveyor.yml Remove some crufty AppVeyor configuration 2018-09-12 11:08:19 -07:00
.eslintignore Applied eslint from main .eslintrc to examples (#418) 2018-07-08 01:02:10 -05:00
.eslintrc Create the web-sys crate mechanically from WebIDL (#409) 2018-07-09 16:35:25 -07:00
.gitattributes add .gitattributes to mark WebIDL as vendored 2018-07-11 18:48:51 -04:00
.gitignore Bump to 0.2.18 2018-08-27 13:37:55 -07:00
.travis.yml ci: remove hack for broken libLLVM.so in nightly 2018-09-12 14:09:00 -07:00
build.rs Implement AsRef<JsValue> for Closure<T> 2018-09-06 14:46:59 -07:00
Cargo.toml Add paint example 2018-09-13 02:10:36 +03:00
CHANGELOG.md Bump to 0.2.21 2018-09-06 22:10:11 -07:00
CONTRIBUTING.md Point to the guide's contributing section instead of CONTRIBUTING.md 2018-06-19 12:05:52 -07:00
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LICENSE-MIT Add license texts 2017-12-18 14:45:06 -08:00
package.json Another attempt to fix CI 2018-09-12 10:39:26 -07:00
publish.rs Bump to 0.2.18 2018-08-27 13:37:55 -07:00
README.md Fix linls 2018-09-16 08:19:18 -04:00

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.