---
# System prepended metadata

title: 89th meeting of TC39

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# 89th meeting of TC39

- TCQ: https://tcq.app/meeting/o1x7
- Hallway track: https://hubs.mozilla.com/oAAvRHu/tc39
- Agenda: https://github.com/tc39/agendas/blob/main/2022/03.md
- Reflector: https://github.com/tc39/Reflector/issues/420

## Day 1 ([notes](https://mths.be/tc39day1))

<details>

<summary>10:00 to 15:00 EDT (UTC -04:00) on 28th March</summary>

### 10:00-12:00
    
- Opening & Welcome (Brian)
- Volunteers for note-taking
- Adoption of the agenda
- Approval of the minutes from last meeting
- 2m Meeting Planning Update (Rob)
- 10m Copyright Policy Update (Yulia)
- 15m Secretary's Report
- 15m ECMA262 Status Updates
- 15m ECMA402 Status Updates
- 15m ECMA404 Status Updates
- 15m Test262 Status Updates
- Updates from the CoC Committee
- 5m remove tables of Unicode property values and aliases (#2649) (Michael Ficarra)
- 10m remove callerRealm from HostEnsureCanCompileStrings (#2670) (Kevin Gibbons)
- 15m Can we try to remove gross use of @@species in the TypedArray constructor (#2677) (Shu-yu Guo)
- 15m handle broken promises in AsyncGenerator.prototype.return (#2683) (Kevin Gibbons)
- 15m Array Grouping Status Update (Justin Ridgewell)

### lunch (60 minutes)

### 13:00-15:00

- 60m Pattern matching for Stage 2 (Tab Atkins-Bittner) 🔒
- 60m Decorators for Stage 3 (Chris Hewell Garrett) 🔒

</details>

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

<details>

<summary>10:00 to 15:00 EDT (UTC -04:00) on 29th March</summary>

### 10:00-12:00
    
- 30m Function.prototype.once for Stage 1 (J. S. Choi) 🔒
- 30m ShadowRealms Updates (Leo Balter) 🔒
- 30m Temporal update and normative changes (Philip Chimento) 🔒
- 30m Bikeshedding call-this syntax (J. S. Choi) 🔒

### lunch (60 minutes)

### 13:00-15:00
    
- 30m RegExp set notation + Unicode properties of strings for Stage 3 (Mathias Bynens & Markus Scherer) 🔒
- 90m Types as Comments for Stage 1 (Daniel Rosenwasser, Rob Palmer, Romulo Cintra) 🔒

</details>

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

<details>

<summary>10:00 to 15:00 EDT (UTC -04:00) on 30th March</summary>

### 10:00-12:00

- 30m Units Conversion For stage 1 (Younies Mahmoud)
- 30m Intl.MessageFormat for Stage 1 (Eemeli Aro)
- 60m New integrity level, a try to unify limited array buffer and read only collection proposal (Jack Works and Mark Miller)
- 15m Decorators #417 (follow-on)

### lunch (60 minutes)

### 13:00-15:00

- 30m Resizable buffers normative changes for `TA#set` and `TA#subarray` (Shu-yu Guo)
- 30m Change Array by Copy for Stage 3 (Ashley Claymore)
- 60m String.dedent Status Update (Justin Ridgewell)
- 15m Incubation Chartering (Shu)    
</details>

## Day 4 ([notes](https://mths.be/tc39day4))

<details>

<summary>10:00 to 15:00 EDT (UTC -04:00) on 31st March</summary>

### 10:00-12:00

- 120m extending built-ins (Kevin Gibbons and Michael Ficarra) 🔒

### lunch (60 minutes)

### 13:00-15:00
    
- 55m Holistic discussion of TC39 dataflow proposals (J. S. Choi)
- 20m Decorators: Continuation 2 (Chris Garrett)
- 45m Continuation:  Types as Comments for Stage 1 (Daniel Rosenwasser, Rob Palmer, Romulo Cintra) 

</details>

***

## Overflow

### From agenda

### Timebox overrun

## Schedule constraints

 - Jordan Harband will not be present on Day 3 (Wednesday), and would prefer to be present for (in order of importance): pattern matching, types as comments, extending builtins, bind-this, destructuring private fields, decorators, logical default assignment, Temporal, once, ShadowRealms

- Philip Chimento (Temporal) would prefer not to be scheduled as the first item on any day, but will deal with it if necessary

- Mathias Bynens & Markus Scherer (RegExp `v` flag) can only present on Tuesday Mar 29 between 13:00 and 14:00 EDT.

- Nicolò Ribaudo will not be present on Monday 28th after 14:00 EDT and on Thursday 31st before 13:00 EDT, and would like to be present for "Change Array By Copy for Stage 3" and "Bikeshedding pipe operator’s topic token"

- Kevin and Michael cannot do the "extending built-ins" discussion on Monday

- Mark Miller will be absent for one hour, from 10amPDT/1pmEDT to 11amPDT/2pmEDT on Tuesday March 29. The sessions I would prefer not to miss, from highest to lowest priority, are:
   - New integrity level (must not miss)
   - extending built-ins
   - Decorators
   - remove callerRealm from HostEnsureCanCompileStrings
   - ShadowRealm Updates
   - Pattern Matching

- Chris Hewell Garrett will not be present on Tuesday March 29th between 10:00 EDT and 13:00 EDT, and would like to present "Decorators for Stage 3" at any other time.

- J. S. Choi will not be available on Monday, March 28 between 1:00 PM EDT / 10 AM PDT and 2:30 PM EDT.

- Jack Works will not be availabe on 8~9 AM PST of the 4th day.

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