This Week in Rust and WebAssembly 15

Hello and welcome to another issue of This Week in Rust and WebAssembly!

Rust is a systems language pursuing the trifecta: safety, concurrency, and speed.

WebAssembly is a stack-based virtual machine and instruction set. It is fast, safe, portable, and part of the open Web platform. By compiling to WebAssembly, we can run Rust code on the Web!

This is a weekly summary of Rust and WebAssembly’s progress and community.

Did we miss something? Tweet to us at @rustwasm or send us a pull request.

Want to get involved in Rust and WebAssembly? Join the Rust and WebAssembly working group!

News and Blog Posts from Around the Web

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Standardizing WASI: A system interface to run WebAssembly outside the web
- @alexcrichton already has a pull request to add a wasm32-unknown-wasi target for Rust!
RustVolley is a reimplementation of the Blobby Volley 2 game in Rust and Wasm
- Source
- Live Demo
CloudFlare’s new wrangler CLI tool lets you deploy Rust-generated Wasm on CloudFlare workers
Fastly open sources Lucet: a native WebAssembly compiler and runtime. Its built with Rust on top of Cranelift and supports WASI.

Updates from `rustwasm/*`

🎉 Welcome @Pauan to the Rust and WebAssembly working group core team! 🎉

RFCs

New RFCs

None.

Final Comment Period RFCs

Add an amendment to the RFC process

Merged RFCs

None.

Working Group Meetings

Gloo

Gloo Update: Onion Layers, Timers, and Events
@Aehmlo split up the gloo_timers crate’s public API to use callbacks and futures submodules, as we collectively agreed upon in other issues.
@cbrevik implemented the gloo_console_timer crate, which provides scoped closures and RAII-style helpers for working with console.time and console.timeEnd.
@OddCoincidence updated the gloo_timers internals to use wasm_bindgen::closures::Closure::once for setTimeout.
@RyLev added some initial Azure Pipelines continuous integration tests for Gloo.
@David-OConnor added the skeleton of an mdbook guide for Gloo.

`wasm-bindgen`

@alexcrichton tweaked the no-modules target’s generated JavaScript glue for instantiating Wasm modules to support CloudFlare workers (and other environments where x instanceof WebAssembly.Module might fail, like across <iframe>s)
@alexcrichton made it so that our emitted JS glue for reflecting Rust closures as JS functions will properly detect and protect against use-after-free from the JS side.
@alexcrichton fixed a bug where Rust structs exported as JS didn’t always emit the JS classes glue in a deterministic order.
@fitzgen made the “without a JS bundler” example use wasm-pack build --target web, now that its supported in the latest wasm-pack release.
@alexcrichton cleaned up the wasm-bindgen CLI’s options to take --target blah instead of --blah (which still exist but are deprecated).
@stevebob enabled mdbook’s link checking tests for the wasm-bindgen guide to our continuous integration tests.
@alexcrichton implemented rustwasm/rfcs#8 to enable transitive crates dependencies on npm packages.
@RReverser added the constructor property to js_sys::Object.
@alexcrichton fixed sending large u32s from Wasm to JS.
@RReverser consistently exposed is_like_none for our generated JS glue, fixing a bug along the way.
@RReverser simplified the ABI representation of Option<char>.
@alexcrichton migrated all the wasm-bindgen-* crates to Rust 2018 edition.
@RReverser made iterating over JS objects via the JS iteration protocol faster by removing redundant property string decoding.
@RReverser made a special version of passing strings from JS to Wasm when we are targeting Node.js that is faster than using Node.js’s TextEncoder implementation.

`wasm-pack`

@alexcrichton fixed a panic that could happen when installing the wasm-bindgen CLI tool.

Requests for Contribution