# 108^th^ Meeting of TC39

- Agenda: https://github.com/tc39/agendas/blob/main/2025/05.md
- Reflector: https://github.com/tc39/Reflector/issues/558 (has notes and TCQ)

## Agenda key

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

| Emoji | Meaning |
| :---: | :--- |
| ❄️ | 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 |

## Day 1

<details>

<summary>10:00 to 17:00 Europe/Madrid on Wednesday</summary>

### 10:00-12:00 (full)

- Opening & Welcome (15m, Ujjwal Sharma)
- Opening of the meeting
- TC39 follows its Code of Conduct
- Introduction of attendees
- Host facilities, local logistics
- Overview of communication tools
- Quick recap of meeting IPR policy
- Reminder to review GitHub Delegate teams (Jordan Harband)
- <details>
<summary>Note about meeting transcriptions</summary>
A detailed transcript of the meeting is being prepared and will be eventually posted on GitHub. You may edit this at any time during the meeting in Google Docs for accuracy, including deleting comments which you do not wish to appear. You may also request corrections or deletions after the fact, by editing the Google Doc (in the first two weeks after the TC39 meeting) or subsequently making a PR in the notes repository or contacting the TC39 chairs.
</details>
- 🗒️ Call for note-takers
- Adoption of the agenda
- Presenters: please be on the lookout for messages from chairs; we may need to move topics forward if time frees up.
- Approval of the minutes from last meeting
- Next meeting host and logistics
- Secretary's Report ([slides](TBD)) (15m, Aki Rose-Braun)
- Project Editors’ Reports
- [ECMA262](https://github.com/tc39/ecma262) Status Updates (5m, Kevin Gibbons)
- [ECMA402](https://github.com/tc39/ecma402) Status Updates (5m, Ujjwal Sharma)
- [ECMA404](https://www.ecma-international.org/publications/standards/Ecma-404.htm) Status Updates (1m, Chip Morningstar)
- [Test262](https://github.com/tc39/test262) Status Updates (5m, Philip Chimento)
- Task Group Reports
- TG4: Source Maps (5m, Nicolò Ribaudo)
- TG5: Experiments in Programming Language Standardization (5m, Mikhail Barash)
- Normative: Add "Late Errors for Function Call Assignment Targets" to Annex B ([#3568](https://github.com/tc39/ecma262/pull/3568), [slides](https://docs.google.com/presentation/d/1V8QKaDqqAXfuwR3Ymi3blgT_auPalM3ZYXgAjyaLN4U/edit?usp=sharing)) (Ross Kirsling, 10m)
- Normative: Added note about sets of locales for web browser implementations needing to not change as a result of user behaviour ([ecma402#780](https://github.com/tc39/ecma402/pull/780)) (Ujjwal Sharma, 10m)
- Normative: Add 8 new numbering systems for Unicode 16 ([ecma402#929](https://github.com/tc39/ecma402/pull/929)) (Ujjwal Sharma, 10m)
- 🔒(RGN) Temporal status update and normative change ([proposal](https://github.com/tc39/proposal-temporal), [slides](https://ptomato.name/talks/tc39-2025-05/)) (Philip Chimento, 20m)
- Intl Locale Info Stage 3 Update: [Normative: Return *undefined* if direction is unknown](https://github.com/tc39/proposal-intl-locale-info/pull/101) ([proposal](https://github.com/tc39/proposal-intl-locale-info/)) (Ujjwal Sharma, 15m)
- ❄️ Maintaining Proposal Topics ([slides](https://docs.google.com/presentation/d/1jWTwZ91AbZvS8OYwDzmNdG4CmN20oyBn9qPHd3FmOQI/edit?usp=sharing)) (Mikhail Barash, J. S. Choi, Michael Ficarra, 30m)

### Lunch (60 minutes)

### 13:00-14:30 (full)

- 🔒 AsyncContext web integration brainstorming ([proposal](https://github.com/tc39/proposal-async-context/), [slides](https://docs.google.com/presentation/d/1yBtSvF5z3P4PliB2NziYzm90d27keiX2P9-MfoDvpJs/edit?usp=sharing)) (Andreu Botella, 60m)
- ❄️ Normative: Add Intl.Locale.prototype.variants ([ecma402#960](https://github.com/tc39/ecma402/pull/960)) (Richard Gibson, 30m)

### Mid-afternoon break (30m)

### 15:00-17:00 (full)

- ❄️ Explicit Resource Management for Stage 4 ([proposal](https://github.com/tc39/proposal-explicit-resource-management), [spec PR](https://github.com/tc39/ecma262/pull/3000), [slides](https://1drv.ms/p/c/934f1675ed4c1638/EYcWEHLrSh5Ah2k4eStVfb0B6skl-3qNmTKqqfLZVs9eiw?e=cXHFAt)) (Ron Buckton, 15m)
- ❄️ `Array.fromAsync` for Stage 4 ([proposal](https://github.com/tc39/proposal-array-from-async), [spec PR](https://github.com/tc39/ecma262/pull/3581), [slides](https://docs.google.com/presentation/d/1i100S94niIcnBj9yhm4l0R9-6hCUbjGMi8tzqkGI2RM/edit?usp=sharing)) (J. S. Choi, 30m)
- ❄️ `Error.isError` for Stage 4 ([discussion](https://github.com/tc39/proposal-is-error/issues/7)) (Jordan Harband, 15m)
- 🔒(Decimal) Keep trailing zeros in Intl.NumberFormat and Intl.PluralRules for Stage 1 ([proposal](https://github.com/eemeli/proposal-intl-keep-trailing-zeros)) (Eemeli Aro, 30m)
- 🔒(Trailing) Decimal Stage 1 update ([proposal](https://github.com/tc39/proposal-decimal/), [slides](https://notes.igalia.com/p/tc39-2025-05-decimal-update)) (Jesse Alama, 30m)
- 🔒(JHD,RGN) Iterator Sequencing for Stage 3 ([proposal](https://github.com/tc39/proposal-iterator-sequencing), [slides](https://docs.google.com/presentation/d/1XXAqt72dHIBQBvTRmR4UqOWbEcj_zqoS61NRMwriJ7s)) (Michael Ficarra, 30m)

</details>

## Day 2

<details>

<summary>10:00 to 17:00 Europe/Madrid on Thursday</summary>

### 10:00-12:00 (full)

- IDL for ECMAScript with WebIDL ([proposal](https://github.com/tc39/proposal-idl), [issue](https://github.com/tc39/proposal-idl/issues/7), [slides](https://docs.google.com/presentation/d/10MXBbI994Go9XNNVvWHGeGHlck0TfZLjKNisE5xF5aE)) (Arai, 60m)
- ❄️ ECMA Framework (Samina Husain, 60m)

### Lunch (60 minutes)

### 13:00-14:30 (1h underflow)

- Moving TCQ forward ([repo](https://github.com/zalari/tcq/tree/contemporary-edition)) (Christian Ulbrich, 30m)
- 🔁 Continuation: Decimal Stage 1 update (proposal, slides) (Jesse Alama, 30m)
- 🔒(JHD) `Math.clamp` for Stage 2 or 2.7 ([proposal](https://github.com/tc39/proposal-math-clamp)) (Oliver Medhurst, 30m)

### Mid-afternoon break (30m)

### 15:00-17:00 (full)

- ❄️🔒(JHD,PHE) SeededPRNG for Stage 2 ([proposal](https://github.com/tc39/proposal-seeded-random), [slides](https://docs.google.com/presentation/d/1wCKZx60SxFkhLHPrOHhzTWDrtr-OiE8p7oZWjGtSdmY/edit?usp=sharing)) (Tab Atkins-Bittner, 30m)
- ❄️🔒(PHE) More Random Functions for Stage 1 ([proposal](https://github.com/tc39-transfer/proposal-random-functions/), [slides](https://docs.google.com/presentation/d/1HXjj3VNjNIvb-LBNLFiepVHZiuSNmtoTqGObuBVGXBQ/edit?usp=sharing)) (Tab Atkins-Bittner, 30m)
- ❄️(PHE,RGN) Immutable ArrayBuffer for Stage 3 ([proposal](https://github.com/tc39/proposal-immutable-arraybuffer), slides coming) (Peter Hoddie, Richard Gibson, 30m)
- 🔒(JHD,RGN) Iterator Chunking for Stage 2.7 ([proposal](https://github.com/tc39/proposal-iterator-chunking), [slides](https://docs.google.com/presentation/d/1Mse7PDM0vcMg4Ag_SK1_OGwVwrJuVxKz-qaWj2RyX8o)) (Michael Ficarra, 30m)
- 🔁🔒(JHD) Continuation: `Math.clamp` for Stage 2 ([proposal](https://github.com/tc39/proposal-math-clamp)) (Oliver Medhurst, 5m)

</details>

## Day 3

<details open>

<summary>10:00 to 16:30 Europe/Madrid on Friday</summary>

### 10:00-12:30

- TG3: Security (1m, Chris de Almeida by proxy)
- Updates from the [CoC Committee](https://tc39.es/code-of-conduct/#code-of-conduct-committee) (1m, Chris de Almeida by proxy)
- 🔒(JHD) Comparisons (né Assertions) for Stage 1 ([proposal](https://github.com/JakobJingleheimer/proposal-comparisons)) (Jacob Smith, 60m)
- JS Numerics breakout session (Jesse, 90 mins)
- Meeting Closes

### Lunch (60 minutes)

### 13:30-14:00

### 14:00-16:00 (unused 😲)

</details>

***

## Overflow

### From agenda

- 🔒(JHD) Proposed change to the agenda deadline (Chris de Almeida, 30m)

### Timebox overrun

## Schedule constraints

- Samina would prefer the "ECMA Framework" topic to be discussed on Day 2 to give people time to mull it over and bring any questions or doubts the following day.
- J. S. Choi is unavailable until 15:00 (GMT+2) on all days and would strongly prefer 05-28 or 05-29 over 05-30.
- Peter Hoddie is available for the last two hours of each day and would like to be present for the Immutable ArrayBuffer topic and all entropy-related topics.
- Jesse Alama would prefer that the decimal update be presented after Eemeli Aro's "keep trailing zeroes", even though the former is at stage 1 and the latter is at stage 0.
- Jordan Harband will only be at the last 2 hours of each day, and would like to be present for: Error.isError, SeededPRNG, Comparisons (né Assertions), Math.clamp, Iterator chunking, deadline change, Iterator sequencing
- Tab Atkins-Bittner is not available the last hour of each day (16:00 to 17:00), as that's "make breakfast/lunch for the wife" time, so don't schedule their topics (SeededPRNG, More Random Functions) then.
- Richard Gibson strongly prefers the last 3 hours of each day, and would like to be present for: Intl.Locale.prototype.variants, Temporal, Immutable ArrayBuffer, Iterator Sequencing, Iterator Chunking
- Michal Mocny would like to attend the AsyncContext discussion at Day 1, 1300.

<style>summary { font-weight: bold; }</style>