Agenda for the 94th meeting of Ecma TC39

September 24, 2025 · View on GitHub

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Agenda for the 94th meeting of Ecma TC39

  • Host: Remote
  • Dates and times:
    • 10:00 to 15:00 EST (America/New_York) on 30 January 2023
    • 10:00 to 15:00 EST (America/New_York) on 31 January 2023
    • 10:00 to 15:00 EST (America/New_York) on 1 February 2023
    • 10:00 to 15:00 EST (America/New_York) on 2 February 2023
  • Attendee information: https://github.com/tc39/Reflector/issues/454

For meeting times in your timezone, visit Temporal docs and run the code below in the devtools console.

Temporal.ZonedDateTime.from('2023-01-30T10:00[America/New_York]')
  .withTimeZone(Temporal.Now.timeZone()) // your time zone
  .toLocaleString();

Background:

Agenda topic rules

Deadline for advancement eligibility: January 20th, 10:00 EST

  • Note: this time is selected to be precisely 10 days prior to the start of the meeting
  1. Proposals not looking to advance may be added at any time; if after the deadline, please always use a pull request so that members are notified of changes. Note: an unmerged PR counts as ”added” for the purposes of this requirement.
  2. Proposals seeking feedback at stage 0 must be added (and noted as such) prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline.
    1. Such proposals should include supporting materials when possible.
  3. Proposals looking to advance to stage 1 must be added (and noted as such) prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline.
    1. Such proposals must link to a proposal repository and they should link to supporting materials when possible.
  4. Proposals looking to advance to stages 2, 3, or 4 must be added (and noted as such) along with the necessary materials prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline.
    1. Such proposals must link to supporting materials prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline. If these materials change substantially after the deadline, the proposal may be disqualified from advancement, based on the committee’s judgment.
    2. Proposals looking to advance to stage 4 must link to a pull request into the spec, since the process requires one.
  5. Proposal-based agenda items should be sorted primarily by stage (descending), secondarily by timebox (ascending), and finally by insertion date.

Supporting materials includes slides, a link to the proposal repository, a link to spec text, etc.; essentially, anything you are planning to present to the committee, or that would be useful for delegates to review.

Agenda items

  1. Opening, welcome and roll call (Chair)

    1. Opening of the meeting
    2. TC39 follows its Code of Conduct
    3. Introduction of attendees
    4. Host facilities, local logistics
    5. Quick recap of meeting IPR policy
    6. Overview of communication tools
    7. Reminder to review Github Delegate teams (Jordan Harband)

  2. Find volunteers for note taking; note stenography support

  3. Adoption of the agenda

  4. Approval of the minutes from last meeting

  5. Next meeting host and logistics

  6. Secretary's Report (15m, Istvan Sebestyen) (https://github.com/tc39/agendas/blob/main/2023/tc39-2023-002.pdf)

  7. Project Editors’ Reports

    1. ECMA262 Status Updates (slides) (15m)
    2. ECMA402 Status Updates (15m)
    3. ECMA404 Status Updates (15m)
    4. Test262 Status Updates (15m)

  8. Updates from the CoC Committee (15m)

  9. Web compatibility issues / Needs Consensus PRs

    ✓timeboxtopicpresenter

  10. Overflow from previous meeting

    ✓timeboxtopicpresenter
    60mAsync Contexts for Stage 1 (slides)Justin Ridgewell & Chengzhong Wu
    60mPrototype pollution mitigation / Symbol.proto for Stage 1 (slides)Shu-yu Guo
    20mA procedure for multiple active supporters in committee to achieve consensus (slides)Daniel Ehrenberg
    30mDocumenting Stage 3 proposals which are not ready to ship (PR, slides)Daniel Ehrenberg

  11. Incubation call chartering (15m on the last day)

  12. Short (≤30m) Timeboxed Discussions

    ✓timeboxtopicpresenter
    10mReducing Annex B monkey-patching (PR)Kevin Gibbons

  13. Proposals

    ✓ represents an agenda item which has been presented, and does not indicate stage advancement

    ✓stagetimeboxtopicpresenter
    315mSymbol as WeakMap key for Stage 4 (spec, slides)Ashley Claymore
    315mJSON.parse source text access Stage 3 update (slides, spec)Richard Gibson
    320mChange Array by copy for Stage 4 (spec, slides)Ashley Claymore
    320mIntl.NumberFormat V3 for Stage 4 (spec, slides)Shane F. Carr
    320mIntl.DurationFormat Stage 3 update (Slides TBW)Ujjwal Sharma
    330mIntl Locale Info API Stage 3 update (Slides, spec)Frank Yung-Fong Tang
    330mExplicit Resource Management Stage 3 update (slides, spec)Ron Buckton
    330mParallel async iterators via a tweak to iterator helpers (slides, proposal)Kevin Gibbons
    345mTemporal Stage 3 update and normative PRs (slides, spec)Philip Chimento
    360mProblems with import assertions for module types and a possible general solution + downgrade to Stage 2 (HTML issue, slides, slides for continuation)Nicolò Ribaudo
    230mArrayBuffer transfer for Stage 3 (slides, spec)Shu-yu Guo
    260mAsync Explicit Resource Management for Stage 3? (slides, spec)Ron Buckton
    130mIntl era and monthCode for Stage 2 (slides, spec)Frank Yung-Fong Tang
    130mSymbol Predicates for stage 2Jordan Harband
    160mgetIntrinsic, with an iterator for stage 2 (slides)Jordan Harband

  14. Longer or open-ended discussions

    ✓timeboxtopicpresenter
    30mDiscuss SuppressedError argument overlap: error and cause (issue)Jordan Harband
    30mDecorator context.access object API (issue)Ron Buckton
    30mDecorators and export Ordering (issue, slidesDaniel Rosenwasser, Ron Buckton

  15. Overflow from timeboxed agenda items (in insertion order)

    ✓topicpresenter

  16. Other business

    1. Thank host

  17. Adjournment

Schedule constraints

Schedule constraints should be supplied here 48 hours before the meeting begins so that the Chairs can take them into account when preparing the schedule.

Normal Constraints

  • Chengzhong Wu is attending from Hangzhou, preference for the Async Contexts topic being discussed at the first two hours of the meeting, any of the days.
  • Anne van Kesteren can only attend in the first two hours of any day, and would like to be present for the "Problems with import assertions for module types" presentation
  • Shu-yu Guo cannot attend January 30, 8:30 - 9:00 AM PT / 11:30 - 12:00 AM ET, please don't schedule his items at that slot. Also, I need to consult with some V8 folks who are OOO until Jan 30 about AsyncContext, please schedule that on Feb 1 or Feb 2
  • Santiago Diaz cannot attend January 31 and needs to be present for the Prototype Pollution agenda item.
  • Jack Works: I'm interested in the following topics (from most important to least important): Prototype pollution mitigation / Symbol.proto, getIntrinsic, Problems with import assertions for module types and a possible general solution, Async Explicit Resource Management, Symbol Predicates Proposal, Symbol as WeakMap key. I'm available on any day, but it is midnight for me. I prefer those topics are continuously presented (no other topics in the middle). Those topics should not be presented earlier than the scheduled time if possible, otherwise I may miss it.
  • Michael Saboff: I cannot attend January 31, 13:00-15:00 EST. I'd like to be present for the Problems with Import Assertions discussion.
  • it would be ideal if the SuppressedError topic was immediately before, or after, the Explicit Resource Management update topic, since they're about the same proposal
  • Yulia Startsev can only attend morning sessions. For overflow topics this meeting I would like to be present, and request that those go in the mornings.

Late-breaking Schedule Constraints

  • The outcome of "Decorator context.access object API" will affect the TypeScript 5.0 RC at the end of February and needs to be discussed this meeting.
  • The outcome of "Decorators and export Ordering" will affect the TypeScript 5.0 RC at the end of February and needs to be discussed this meeting.

Dates and locations of future meetings

DatesLocationHost
2023-03-21 to 2023-03-23Seattle, USF5
2023-05-15 to 2023-05-18Remote: "Chicago"
2023-07-11 to 2023-07-13Bergen, NorwayUniversity of Bergen
2023-09-26 to 2023-09-28Tokyo, JapanBloomberg
2023-11-27 to 2023-11-30Remote: "SF"