Summary for the 64th meeting of Ecma TC39

Ecma Technical Committee 39 held three day meeting at Bloomberg in NYC on May 22nd - May 24th, 2018. Agenda can be found here (note: committee has adopted new agenda format based on the stage of proposals)

TC39 discussed 10 new proposals. 7 entered staging process to discuss towards specification, and 3 remains at Stage 0 for further investigation before consensus.

• Sequence properties in Unicode property escapes
• Module Keys
• Class Static Block
• Class Access Expressions
• Pattern Matching
• RegExp Match array offsets

• Well-formed JSON.stringify

• Tagged Collection Literals
• Symbol.thenable
• "Blöcks" syntax

• Object.fromEntries
• Set Methods
• Realms
• Function.prototype.toString() censorship. Please also refer to continued discussion
• Top Level Await

• Symbol.prototype.description
• Static class features

• Optional catch binding
• ECMAScript as a superset of JSON

A conflict with other proposal was found, champion group and committee has decided to move following proposal from Stage 3 to Sage 2. Please see notes for more information.

• Numeric separators.

These proposals were discussed but did not advance to next stage at the meeting. Please refer to "Conclusion / Resolution" section on the notes to see the outcome of discussion.

• Binary AST
• Function.prototype.toString revision
• String.prototype.codePoints
• Class fields

Status updates from proposals working twards stage advancement.

• Intl Updates
• Decorators
• Array.prototype.flatten rename to flat
• Big Int
• String.prototype.matchAll

• Normative: Cleanup Time Values and Time Range
• Normative: Add export * as ns from "mod” to Export production and Module Semantics
• SuperProperty evaluation order

• Rename Atomics.wake
• Updates and a question to resolve on String.prototype.matchAll

Topics related to ECMAScript specification activities.

• Supporting other languages in ES module graphs
• Stopping exfiltration: Massive privacy violations vs boundaries

• ~400 new tests added to Test262 from various contributors.
• CoC commmittee updates
• Update to the How We Work Documentation project and Website
• 2019 / 2020 meeting scheduling
• TC53 - variables which are based on ECMAScript
• Editor group update
• ECMAScript PDF is most downloaded spec in ECMA