Updates from the 98th TC39 meeting

There were several items on the agenda, this post focuses on feature proposals and their progress from the 97th TC39 meeting [26-28 September 2023].

Stage 4:

• Resizable ArrayBuffer: Resizable and growable ArrayBuffers.

Sage 2:

• ShadowRealm: ECMAScript Proposal, specs, and reference implementation for Realms [Stage 3 -> 2].

• RegExp.escape: Proposal for investigating RegExp escaping for the ECMAScript standard.

Stage 1:

• Joint Iteration: synchronise the advancement of multiple iterators.

• Locale Extensions:Allow Web platform engines to use limited system-defined user preferences.

• Iterator Sequencing: Create iterators by sequencing existing iterators.

• Negated in and instanceof:negated in and instanceof operators.

• Stable Formatting: Stable Intl-inspired formatting options.

Withdrawn:

• FinalizationRegistry#cleanupSome: This method was planning to enable library authors to clean up without yielding to the event loop.

• Symbol.thenable: Was planning to avoid thenable behavior, a modifier should be added to an object for Promise.resolve awareness.