Updates from 83rd meeting of TC39

#tc39 #javascript

There were several items in the agenda, this post mainly focuses on feature proposals and their progress.

Stage 4:

RegExp Match Indices provide additional information about the start and end indices of captured substrings relative to the start of the input string.
Top level await enables modules to act as big async functions: With TLA, ECMAScript Modules (ESM) can await resources, causing other modules who import them to wait before they start evaluating their body.

Stage 3:

Accessible Object.prototype.hasOwnProperty(): Proposal for an Object.hasOwn() method to make Object.prototype.hasOwnProperty() more accessible.
Intl.DisplayNames V2: In Intl.DisplayNames API, we already cover language, region, script, and currency. This proposal enhance the Intl.DisplayNames API and cover more.
Extend TimeZoneName Option: Extend the timeZoneName option in Intl.DateTimeFormat object to support more formatted options.
Resizable and Growable ArrayBuffers Growing a new buffer right now requires allocating a new buffer and copying. Not only is this inefficient, it needlessly fragments the address space on 32-bit systems, this proposal makes it easier to have a resizable and growable ArrayBuffer.