Intent to Ship: Symbols as WeakMap keys

[Shu-yu Guo]

Contact emails

s...@chromium.org

Explainer

https://github.com/tc39/proposal-symbols-as-weakmap-keys

Specification

https://tc39.es/proposal-symbols-as-weakmap-keys

Summary

This proposal allows Symbols to be used as keys in WeakMaps, WeakSet, as the referent in a WeakRef, and as the target in a FinalizationRegistry.

Blink component

Blink>JavaScript>Language

TAG review

This is a TC39 JS language feature that doesn't have any interaction with web APIs.

TAG review status

Not applicable

Risks

Interoperability and Compatibility

Gecko: Positive Stage 3 TC39 proposal

WebKit: Positive Stage 3 TC39 proposal

Web developers: No signals

Other signals:

WebView application risks

None?

Debuggability

This proposal adds Symbols as keys to weak collections and weak data structures, which already exist and are debuggable. The V8 inspector was extended [1] to support Symbols in collections. [1] https://chromium-review.googlesource.com/c/v8/v8/+/3930037

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

In test262

Flag name

--harmony-symbol-as-weakmap-key

Requires code in //chrome?

False

Tracking bug

https://bugs.chromium.org/p/v8/issues/detail?id=12947

Estimated milestones

DevTrial on desktop

108

DevTrial on Android

108

Anticipated spec changes

None

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5124046206271488

This intent message was generated by Chrome Platform Status.

[slightlyoff via Chromestatus]

LGTM

[rbyers via Chromestatus]

LGTM2

[Daniel Bratell]

LGTM3

/Daniel

On 2022-11-02 16:53, rbyers via Chromestatus wrote:

LGTM2

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