Inactive proposals are proposals that at one point were presented to the committee but were subsequently abandoned, withdrawn, or rejected.
| Proposal | Champion | Rationale |
|---|---|---|
| Callable class constructors | Yehuda Katz Allen Wirfs-Brock |
Withdrawn: can be solved with decorators |
{Set,Map}.prototype.toJSON |
David Bruant Jordan Harband |
Rejected: better solved by a custom replacer function. |
| Typed Objects | Till Schneidereit (previously Dmitry Lomov, Niko Matsakis) | Postponed: waiting for WebAssembly requirements to become clearer |
| Object enumerables | Leo Balter John-David Dalton |
Rejected |
| Cancelable Promises | Domenic Denicola | Withdrawn |
| Proposed Grammar change to ES Modules | Bradley Farias | Rejected: No consensus on this specific solution. |
| Dynamic Module Reform | Caridy Patiño | Withdrawn: we decided to preserve the current semantics |
| SIMD.JS - SIMD APIs | Peter Jensen Yehuda Katz |
Stage 1: Start with SIMD in WASM; implementations not pursuing SIMD.js for now. |
| Updates to Tail Calls to include an explicit syntactic opt-in | Brian Terlson Eric Faust |
Inactive |
| Object.shallowEqual | Sebastian Markbage | Withdrawn |
%constructor%.construct |
James M Snell | Withdrawn |
Builtins.typeOf() and Builtins.is() |
James M Snell | Withdrawn: can be solved in other ways |
| Tagged Collection Literals | Kat Marchán | Withdrawn: pursuing when new syntax and other alternatives |
Date.parse fallback semantics |
Morgan Phillips | Inactive; likely replaced by uniform parsing of quasi-standard Date.parse input |
| Distinguishing literal strings | Mike West Adam Klein |
Withdrawn: Trusted Types no longer a dependent |
| Annex B — HTML Attribute Event Handlers | Allen Wirfs-Brock | Withdrawn per PR comment |
| Normative ICU Reference | Domenic Denicola | Withdrawn; champion is no longer participating in TC39 |
| Zones | Domenic Denicola Miško Hevery |
Withdrawn; champion is no longer participating in TC39 |
| Blöcks | Domenic Denicola | Withdrawn; champion is no longer participating in TC39 |
| RegExp Atomic Groups & Possessive Quantifiers | Justin Ridgewell | Never presented; engines are not interested in the feature, mainly because it doesn't solve backtracking for most users |
| RefCollection | Robin Ricard | Withdrawn; replaced with Symbols as WeakMap keys; also there were OCAP/membrane concerns around providing a globally available pre-instantiated RefCollection |
| Generic Comparison | Hemanth HM Jordan Harband |
Withdrawn: replaced with Array Equality |
from ... import |
Bradley Farias | Never presented; preliminary feedback about syntax cost not being worth the weight |
| TypedArray stride parameter | Shu-yu Guo | Withdrawn: concern about performance implications, and the proposal is not expressive enough |
| Unused Function Parameters | Gus Caplan | Rejected: the need to solve the problem does not outweigh the hazards |
| Improving iteration on Objects | Jonathan Keslin | Withdrawn: concern about need for such an API |
String.prototype.at |
Mathias Bynens Rick Waldron |
Obsoleted by renamed String.prototype.item proposal |
ArrayBuffer.prototype.transfer |
Domenic Denicola Shu-yu Guo |
Withdrawn: superseded by Resizable Buffers |
deprecated |
James M Snell | Never presented |
| Function helpers | J. S. Choi | Presented and rejected before Stage 1 on 2021-10; split up into multiple subsequent proposals |
"use module" |
Dave Herman | Inactive; champion does not wish to pursue |
| Function.pipe and flow | J.S. Choi | Withdrawn: rejected for stage 1 |
Symbol.thenable |
Gus Caplan Jordan Harband Myles Borins |
Withdrawn; changing thenability on Module Namespace objects is not web compatible, and allowing non-Promise use of "then" is not worth slowing down all Promise operations |
WeakRefs cleanupSome |
Yulia Startsev Daniel Ehrenberg |
Withdrawn; subsumed by WebAssembly JS Promise Integration, which avoids the long task issue |
| Operator overloading | Daniel Ehrenberg | Withdrawn |
| Extensible numeric literals | Daniel Ehrenberg | Withdrawn |
| JSON.tryParse | Jack Works | Rejected; some deemed this too specific a solution for a generalized language-wide problem |
| UUID | Benjamin Coe | Withdrawn; moved to crypto.randomUUID() in February 2023 |
Math Extensions |
Rick Waldron | Withdrawn: no interested champions in February 2024 |
| Generator arrow functions | Sergey Rubanov Brendan Eich |
Withdrawn: no interested champions in February 2024 |
Math.signbit: IEEE-754 sign bit |
JF Bastien | Withdrawn: no interested champions in February 2024 |
| Getting last element of Array | Keith Cirkel | Withdrawn; the Array#at proposal supersedes this work. |
| Sequence properties in Unicode property escapes | Mathias Bynens | Withdrawn; subsumed by RegExp v flag with set notation + properties of strings proposal |
See also the active proposals, stage 1 proposals, stage 0 proposals, and finished proposals documents.