Off The Main Thread

In this episode, Surma talks about the Stage 2 proposal "JavaScript Struct", which introduces fixed-layout objects and the ability to share them between realms. Notes & Corrections from Shu: Surma was slightly wrong about why private fields were originally considered problematic for sharability. The problem occurs when a class can be evaluated multiple times: function makeClass() { return class MyClass { #priv; getPrivateField(instance) { return instance.#priv; } }; } const C1 = makeClass(); const C2 = makeClass(); const i1 = new C1(); const i2 = new C2(); // this throws! i1.getPrivateField(i2); This behavior makes it hard to compile private fields just as "slots" on an object, as clearly additional behavior is required. This is somewhat at odds with the goal of achieving a fixed layout. Also, launching is mid-2025 is very optimistic. Resources: SharedArrayBuffer Structs proposal Return overrides Records & Tuples proposal Surma’s buffer-backed-object library for SharedArrayBuffer

After talking about Bazel in one of our previous episodes, we are now looking at Nix, a build system that has been getting increasing attention lately. Resources: OTMT Bazel episode Surma's video on Nix Eelco Dolstra's PhD Thesis Nix & NixOS A branch of Squoosh using Nix Nixpkgs manual Comparison of size and freshness of different package managers Home Manager Nix pills

We're finally getting a  element we can fully control with CSS! A bunch of other stuff needed to be added to the platform to make it work, and the good news is we can use it a lot of them independently of . Resources: Chrome's article on the new , and how you can provide feedback. The CSS appearance property. Nope, I still don't know what it does. The Popover API. "On popover accessibility: what the browser does and doesn’t do" by Hidde de Vries and Scott O'Hara. The CSS anchor positioning API. The previous spatnav spec effort. The hidden attribute until-found value (sorry, I said if-found in the episode). The CSS element function. Timing of cloning for the  element. Animating to height auto. The new entry-exit animation feautres. The proposed command and commandfor attributes which give buttons declaritive activation behavior.

Chrome is experimenting with exposing an LLM to the web platform. Jake and Surma dig into how the API works, and whether something like this could work on the open web. Resources: The explainer ChatGPT functions Chrome's initial vague docs about the feature Gemini terms of use The EURion constellation WebNN