Updates from 80th TC39 meeting

There were few other items on the agenda, this post focuses only on the proposal updates from the the meeting.

Stage 4:

• Intl.DateFormat.prototype.formatRange Add formatRange(date1, date2) and formatRangeToParts(date1, date2) to Intl.DateTimeFormat to enable date range formatting.

Stage 3:

• JSON modules: ability to import a JSON module in a common way across JavaScript environments.

• Ergonomic Brand Checks for Private Fields: Check if an object has a private field, and if not, have some fallback behavior.

Stage 2:

• Module Blocks: Module blocks are syntax for the contents of a module, which can then be imported.

• Intl.DisplayNames: enable developers to get translation of language, region or script display names on the client, part of ECMA-402.

• Intl.DisplayNames V2: A proposal to expose Locale information, such as week data (first day in a week, weekend start day, weekend end day, minimum day in the first week), hour cycle used in the locale, measurement system used in the locale, part of ECMA-402.

Stage 1:

• async do: async do expressions allow you to introduce an asynchronous context within synchronous code without needing an immediately-invoked async function expression.

• Class brand check: class.hasInstance a meta method to check whether o have the class brand of C.

• Extend TimeZoneName Option: Extend the timeZoneName option in Intl.DateTimeFormat object to support more formatted options, part of EMCA 402.

• eraDisplay: eraDisplay option for Intl.DateTimeFormat eraDisplay option may take 3 values: "never", always", "auto".

• regex-set-notation: Adopting Unicode behavior for set notation in regular expressions.

• Escaping Strings for RegExps: escaping a string for use inside a Regular Expression.

• Array find from last: findLast() and findLastIndex() methods on Array.prototype.

• lazy-import: defer module import eval.

• Intl LocaleMatcher: Improve locale negotiation correctness and developer productivity part of ECMA-402.