Agenda for the 106th meeting of Ecma TC39

September 24, 2025 · View on GitHub

Ecma logo

Agenda for the 106th meeting of Ecma TC39

  • Host: F5
  • Dates and times:
    • 10:00 to 17:00 PST (America/Los_Angeles) on 18 February 2025
    • 10:00 to 17:00 PST (America/Los_Angeles) on 19 February 2025
    • 10:00 to 16:00 PST (America/Los_Angeles) on 20 February 2025
  • Location: Seattle, WA
  • Attendee information: https://github.com/tc39/Reflector/issues/547
  • Total duration of scheduled discussions: dynamically computed total of timeboxes on the agenda
gantt
  1 month before the meeting: milestone, 2025-01-08 10:00-0800, 1m
  Proposal advancement deadline: milestone, 2025-02-08 10:00-0800, 1m
  Schedule constraint deadline: milestone, 2025-02-15 10:00-0800, 1m
  Day 1 : day1, 2025-02-18 10:00-0800, 8h
  Day 2 : day2, 2025-02-19 10:00-0800, 8h
  Day 3 : day3, 2025-02-20 10:00-0800, 7h
  todayMarker stroke-width:5px,stroke:#0f0,opacity:0.5

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

Temporal.ZonedDateTime.from('2025-02-18T10:00[America/Los_Angeles]')
  .withTimeZone(Temporal.Now.timeZoneId()) // your time zone
  .toLocaleString();

Background:

Agenda topic rules

Deadline for advancement eligibility: February 8th, 10:00 PST

  • 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, 2.7, 3, or 4, as well as other normative changes to the standard or proposals in stage 3 or later looking to achieve consensus, must be added (and noted as such) along with links to the supporting materials prior to the deadline, or else delegates may withhold consensus for advancement solely on the basis of missing the deadline.
    1. If the supporting materials change substantially after the deadline, delegates may withhold consensus for advancement, based on the committee’s judgment.
    2. For urgent normative changes, the committee is expected to be more forgiving of a missed deadline, since there is generally less material to review than in a stage advancement.
    3. 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 key

When applicable, use these emoji as a prefix to the agenda item topic.

EmojiMeaning
❄️hard schedule constraints apply to this agenda item (e.g. presenter)
🔒schedule constraints apply to this agenda item
⌛️late addition for stage advancement and/or schedule prioritization
🔁continuation of a previous agenda item

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)
    8. TC39 stenography support and legal disclaimer

  2. Find volunteers for note taking

  3. Adoption of the agenda

  4. Approval of the minutes from last meeting

  5. Next meeting host and logistics

  6. Secretary's Report (15m, Samina Husain) (slides)

  7. Election of the 2025 Chair Group, Editors, and Convenors (15m, Aki Rose Braun) (slides)

  8. Project Editors’ Reports

    1. ECMA262 Status Updates (slides) (15m)
      1. NOTE: The 2025 edition will be frozen at the end of this meeting and the IPR opt-out will begin.
    2. ECMA402 (slides) Status Updates (15m)
    3. ECMA404 Status Updates (15m)
    4. Test262 Status Updates (15m)

  9. Task Group Reports

    1. TG3: Security (5m)
    2. TG4: Source Maps (5m) (slides)
    3. TG5: Experiments in Programming Language Standardization (5m)

  10. Updates from the CoC Committee (5m)

  11. Web compatibility issues / Needs Consensus PRs

    timeboxtopicpresenter
    15mDon't call well-known Symbol methods for RegExp on primitive valuesGus Caplan, Luca Casonato

  12. Overflow from previous meeting

    timeboxtopicpresenter

  13. Short (≤30m) Timeboxed Discussions

    timeboxtopicpresenter

  14. Proposals

    stagetimeboxtopicpresenter
    35mFloat16Array for stage 4 (spec PR)Kevin Gibbons
    310mExplicit Resource Management Needs Consensus PR (PR)Ron Buckton
    315mRedeclarable global eval vars for stage 4 (spec PR)Shu-yu Guo
    315mRegExp Escaping for stage 4 (spec PR)Jordan Harband
    320mTemporal normative PR and status update (slides)Philip Chimento
    330mIntl Locale Info API Update in Stage 3 (PR, slide)Frank Yung-Fong Tang
    330mDecorators implementation updates (slides)Kristen Hewell Garrett
    2.710mShadowRealm status update (slides)Philip Chimento
    2.715mimport defer for Stage 3 (tests: all PRs linked to https://github.com/tc39/test262/issues/4215, slides)Nicolò Ribaudo
    230mImmutable ArrayBuffer for stage 2.7 (slides.key, slides.pdf)Mark Miller
    245mRecords & Tuples future directions slidesAshley Claymore
    130mLimited ArrayBuffer update: stay on stage 1 or withdraw?, slidesJack Works
    130mStabilize integrity traits status update (slides.key, slides.pdf, video)Mark Miller
    160mA unified vision for measure and decimal (slides) (continuation slides)Jesse Alama, Eemeli Aro, Shane F Carr
    160mStable Formatting update (PR, slides)Eemeli Aro
    030mError Stack Accessor for stage 1 or 2Jordan Harband
    030mMath.clamp for Stage 1 or 2 (slides)Oliver Medhurst
    030mError.captureStackTrace (slides) for Stage 1Matthew Gaudet
    030mCurtailing the power of "Thenables" (Slides) for Stage 1Matthew Gaudet
    030mNumber.isSafeNumeric (slides) for Stage 1ZiJian Liu

  15. Longer or open-ended discussions

    timeboxtopicpresenter
    45mDecision Making through Consensus - take 2Michael Saboff
    60m (fine to be shorter)Language design goal for consensus: Things should layer (slides)Daniel Ehrenberg

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

    topicpresenter

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

  18. Other business

    1. Thank host

  19. Adjournment

Schedule constraints

Schedule constraints should be supplied here as soon as possible, and at least three days before the meeting begins so that the Chairs can take them into account when preparing the schedule.

Normal Constraints

  • Ron Buckton will not be available from 11:30pm to ~12:30pm on each day.
  • Kristen Hewell Garrett will not be available on Wednesday, Feb 19th until 14:00 PST
  • Matthew Gaudet will be unavailable the afternoon of Thursday Feb 20th.
  • Matthew Gaudet would prefer Error.captureStackTrace, Curtailing the power of "thenables", and Error Stack Accessor happen between 12:00 and 3:00 PST
  • Eemeli Aro will be unavailable during the afternoons of each day, and would like to attend the "unified vision for measure and decimal" discussion.
  • Philip Chimento: mild preference to present ShadowRealm and Temporal back to back, if possible.
  • ZiJian Liu: hope to schedule Number.isSafeNumeric during the last two hours of the first and second days(15:00 - 17:00 PST), or the last hour of the final day(15:00 - 16:00 PST).
  • Waldemar would like to attend Records & Tuples and Measure/Decimal but will not be available on Thursday Feb 20.

Late-breaking Schedule Constraints

  • Ron Buckton needs to be present during the Decorators presentation.