# 98th meeting of TC39

- TCQ: https://tcq.app/meeting/MypE
- Agenda: https://github.com/tc39/agendas/blob/main/2023/09.md
- Reflector: https://github.com/tc39/Reflector/issues/499

## 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 ([notes](https://mths.be/tc39day1))

<details>

<summary>10:00 to 17:00 Asia/Tokyo (UTC + 9) on Tuesday</summary>

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

- Opening & Welcome (15m, Rob Palmer)
- Opening of the meeting
- TC39 follows its Code of Conduct
- Introduction of attendees
- Host facilities, local logistics
- Quick recap of meeting IPR policy
- Overview of communication tools
- Reminder to review Github Delegate teams (Jordan Harband)
- 🗒️ Call for note-takers
<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>
- Adoption of the agenda
- The agenda doth runneth over; please be mindful.
- Approval of the minutes from last meeting
- Next meeting host and logistics
- Secretary's Report [slides](./tc39-2023-040.pdf) (15m, Samina Husain)
- [Guide to converting an Ecma standard from a ecmarkup generated HTML file into an Ecma format printable PDF](./Guide_cnvprocess_AllenWirfsBrock.pdf)
- [Well-formatted PDFs for TC39 Standards in 2022 and Beyond](./PDFsforTC39.Standards_AllenWirfsBrock.pdf)
- Project Editors’ Reports
- [ECMA262](https://github.com/tc39/ecma262) ([slides](https://docs.google.com/presentation/u/1/d/14EMR7dyp5Fe7bZITKNP9upeV4OGo-wwtzWbPsC4cvk0/edit)) (10m, Kevin Gibbons)
- [ECMA402](https://github.com/tc39/ecma402) Status Updates (15m, 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 (15m, Richard Gibson / Jordan Harband)
- Task Group Reports
- TG3: Security ([slides](https://docs.google.com/presentation/d/1FSukmXtkL0rXqkmgScidr7tZzP9jagxxIyHQllxGWSY/edit?usp=sharing)) (10m, Michael Ficarra)
- TG4: Source Maps (5m, Jon Kuperman)
- Updates from the [CoC Committee](https://tc39.es/code-of-conduct/#code-of-conduct-committee) (5m, Jordan Harband)
- needs consensus: [ecma402#758](https://github.com/tc39/ecma402/pull/758) Normative: Change the hourCycle default logic (5m, Ben Allen)
- ⌛️ needs consensus: [ecma402#780](https://github.com/tc39/ecma402/pull/780) Normative: Added note about sets of locales for web browser implementations needing to not change as a result of user behaviour #780 (10m, Ben Allen)
- needs consensus: [ecma402#811](https://github.com/tc39/ecma402/pull/811) Normative: Fix order of rounding* option reads and resolvedOptions() (10m, Ben Allen)
- [Update GetSubstitution to match reality](https://github.com/tc39/ecma262/pull/3157) (10m, Richard Gibson)
- ⌛️ needs consensus: [ecma402#788](https://github.com/tc39/ecma402/pull/788) Normative: Allow UTC offset time zones (20m, Ben Allen)
- [Import Attributes](https://github.com/tc39/proposal-import-attributes/) Implementer Feedback ([slides](https://docs.google.com/presentation/d/1AvdsT0k_etbelbE_HEdEY8YHLbsDv0ObWBaAhDm3TAE/)) (15m, Daniel Minor)
- [Array Grouping](https://github.com/tc39/proposal-array-grouping/issues/60) update (5m, Jordan Harband)
- [ArrayBuffer transfer](https://github.com/tc39/proposal-arraybuffer-transfer/issues/12) update (5m, Jordan Harband)
- [Symbol predicates](https://github.com/tc39/proposal-symbol-predicates/issues/11) update (5m, Jordan Harband)
- [Pattern Matching](https://github.com/tc39/proposal-pattern-matching) update (5m, Jordan Harband)

### lunch (60m)

### 13:00-15:00 (full)

- [JSON.parse source text access](https://github.com/tc39/proposal-json-parse-with-source) update (15m, Richard Gibson)
- [Iterator helper web incompat](https://github.com/tc39/proposal-iterator-helpers/issues/286) ([PR](https://github.com/tc39/proposal-iterator-helpers/pull/287)) (30m, Shu-yu Guo & Michael Ficarra)
- [Resizable buffers](https://github.com/tc39/proposal-resizablearraybuffer) for Stage 4 (30m, Shu-yu Guo)
- 🔒 Stage 3 update of [Intl Locale Info API](https://github.com/tc39/proposal-intl-locale-info) ([Slides](https://docs.google.com/presentation/d/1pr3lp_gPcaitmmiQZq2xQGEoG-1cfpOU1agLKAYmPqQ/edit#slide=id.g15fa621a7a8_0_37)) (30m, Frank Yung-Fong Tang)
- [Async Iterator Helpers status update](https://github.com/tc39/proposal-async-iterator-helpers) (15m, Kevin Gibbons)
- [Throw Expressions](https://github.com/tc39/proposal-throw-expressions) for Stage 3 (30m, Ron Buckton)

### Break (15m)

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

- [Intl.MessageFormat](https://github.com/tc39/proposal-intl-messageformat): Stage 1 update and discussion ([slides](https://docs.google.com/presentation/d/15lwZipk0k5pMscSBbEPpMySsnM_qd4MOo_NqmmKyS-Q/)) (45m, Eemeli Aro)
- [RegExp.escape](https://github.com/tc39/proposal-regex-escaping) for stage 2 (30m, Jordan Harband)
- reviving [export default from](https://github.com/tc39/proposal-export-default-from); for stage 2? (30m, Jordan Harband)
- [DataView get/set Uint8Clamped methods](https://github.com/tc39/proposal-dataview-get-set-uint8clamped) for stage 2 (30m, Jordan Harband)
- Withdrawing [Symbol.thenable](https://github.com/devsnek/proposal-symbol-thenable) (1m, Jordan Harband)

</details>

## Day 2 ([notes](https://mths.be/tc39day2))

<details>

<summary>10:00 to 17:00 Asia/Tokyo (UTC + 9) on Wednesday</summary>

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

- 🔒 [ShadowRealm](https://github.com/tc39/proposal-shadowrealm): Implementer Feedback and Demotion to Stage 2 ([slides](https://docs.google.com/presentation/d/1WJd9g3df_ibVHK3LdoKX2FboDwYQBUBJNxuRAWOYYbM/)) (30m, Daniel Minor)
- [AsyncContext](https://github.com/tc39/proposal-async-context) update ([slides](https://docs.google.com/presentation/d/12A3LYlqgzmqRqE0mJ47GRWB6uKlqoFXiWE9gsxpRje4/edit?usp=sharing)) (15m, Chengzhong Wu)
- [Get Intrinsics](https://github.com/tc39/proposal-get-intrinsic) for stage 2, with two possible shapes/paths? (30m, Jordan Harband)
- [iterator sequencing](https://github.com/michaelficarra/proposal-iterator-sequencing) for Stage 1 ([slides](https://docs.google.com/presentation/d/1myebbwYiacqh419Vi2-EjtcQcaWpyMlZ8lbayi5OAZs)) (30m, Michael Ficarra)
- [Structs and shared structs](https://github.com/tc39/proposal-structs) update (60m, Shu-yu Guo)

### lunch (60m)

### 13:00-15:00 (full)

- [Type Annotations](https://github.com/tc39/proposal-type-annotations): Stage 1 update and discussion ([slides](https://docs.google.com/presentation/d/1rwrWQkYityiK1pf5UpkgRYMKL8euqtDrrrbngMKJusY/edit?usp=sharing)) (60m, Daniel Ehrenberg and Daniel Rosenwasser)
- [Decimal](https://github.com/tc39/proposal-decimal): Stage 1 update and discussion ([slides](https://docs.google.com/presentation/d/1xOvWslwKi6evMWMYk1PQv9H0IEIhsifHbEBh2BOqHa0/)) (60m, Jesse Alama)

### Break (15m)

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

- [joint iteration](https://github.com/michaelficarra/proposal-joint-iteration) for Stage 1 ([slides](https://docs.google.com/presentation/d/18Xnd--QmYV8c-qw3tGe4zvlIfF5A-CdXr-qW1tW6j4o)) (30m, Michael Ficarra)
- TDZ, what is it good for? (60m, Shu-yu Guo)
- [Stable Formatting](https://github.com/eemeli/proposal-stable-formatting) for Stage 1 ([slides](https://docs.google.com/presentation/d/1p1Xgywv1qfY54gnfHUM6PXQafqgf7wY98znxbolmP2c/edit?usp=sharing)) (30m, Eemeli Aro)

</details>

## Day 3 ([notes](https://mths.be/tc39day3))

<details open>

<summary>10:00 to 16:00 Asia/Tokyo (UTC + 9) on Thursday</summary>

### 10:00-12:00 (15m underflow)

- 🔒 [Uint8Array-Base64](https://github.com/tc39/proposal-arraybuffer-base64): are we doing multi-shot? ([issue](https://github.com/tc39/proposal-arraybuffer-base64/issues/13)) (45m, Kevin Gibbons)
- [Negated `in` and `instanceof` operators](https://github.com/gorosgobe/proposal-negated-in-instanceof) for Stage 1 ([slides](https://docs.google.com/presentation/d/1vwNOjUiUvy6TzK6t0Mb8qgyKwBNszly9HibJJpUa_Eo/edit?usp=sharing)) (30m, Pablo Gorostiaga Belio)
- [Locale Extensions](https://github.com/ben-allen/locale-extensions) for Stage 1 (slides TBD) (30m, Ben Allen)
- 🔁 Continuation: [Uint8Array-Base64](https://github.com/tc39/proposal-arraybuffer-base64): are we doing multi-shot? ([issue](https://github.com/tc39/proposal-arraybuffer-base64/issues/13)) (1m, Kevin Gibbons)
- Withdrawing [FinalizationRegistry cleanupSome](https://github.com/tc39/proposal-cleanup-some) ([slides](https://docs.google.com/presentation/d/18V56wPFL3TZ2hgvK3b9zQsvLaw4aGdy_asxJ_6at_hs/edit#slide=id.p)) (15m, Daniel Ehrenberg)

### lunch (60m)

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

- Stop coercing things pt 2 ([slides](https://docs.google.com/presentation/d/1VwHSzNOAjR6nZkO2DMOAkoyIwaVcjqhT7VOaNiWm8ho/edit)) (60m, Kevin Gibbons)

### Break (15m)

### 14:15-16:00 (full)

- reducing wasted effort due to proposal churn (continued) ([slides](https://docs.google.com/presentation/d/1HtcFY98qWy-LPJLawRIkYzhDEjuEeyArMiNXbCOFcrk/view)) (~~90m~~ 75m, Michael Ficarra)
- 🔁 Continuation: [Throw Expressions](https://github.com/tc39/proposal-throw-expressions) for Stage 3 (15m, Ron Buckton)
- Incubation call chartering (15m, TBD)

</details>

***

## Overflow

### From agenda

- Withdrawing [numeric literal suffixes](https://github.com/tc39/proposal-extended-numeric-literals) ([slides](https://docs.google.com/presentation/d/1me-RkloXmBJhDJKG3rl_q0CYW2KO_QFnvIPmIRmQhsw/edit#slide=id.g27efdfda19b_0_0)) (20m, Daniel Ehrenberg)
- Withdrawing [operator overloading](https://github.com/tc39/proposal-operator-overloading) ([slides](https://docs.google.com/presentation/d/1mT2VmZlC3YmhDsqdxrCxQ5GpLFHFntsb3XCM762eDvg/edit#slide=id.p)) (30m, Daniel Ehrenberg)

### Timebox overrun

## Schedule constraints

- Caridy Patino and Leo Balter would like to be present for the ShadowRealm topic but are limited to the first 2 hours for the meeting each day (10:00 to 12:00 JST).
- Philip Chimento: Would like to be present if possible for (in order of most to least preference) ShadowRealm, stop coercing things, Decimal, withdrawing cleanupSome, get intrinsics. Not available on Day 1 (26th).
- Peter Hoddie: Would like to be present for Base64. Available for first three hours of Day 1 (26th) and Day 3 (28th).
- Frank Tang: Can only attend the meeting on Day 1 (26th) and Day 2 (27th).

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