Stage 2 tracking

[bakkot]

This proposal achieved stage 1 at the March 2018 meeting. This is a tracking issue for getting stage 2.

(I don't believe there's anything more which is strictly required and not yet done except to bring it before the committee again, though a few minor things would be good to get done.)

• Initial spec text
• Major syntax and semantics
• Document several motivating use cases
• Transfer this repo to the TC39 org

[ljharb]

The minor question of the second argument (#13) is something that I think can wait for a followon proposal, unless the committee feels strongly about one of the three directions (no 2nd arg ever, proto, or mapper).

[bathos]

I agree that it’s not essential to the proposed functionality. However I don’t know of any precedent cases for functions whose signatures were expanded after introduction — has that been done before, and would it be considered a backwards incompatibility risk?

[ljharb]

That’s a fair point, and something I’ll bring up in committee.

Regardless, i think “one arg ever” is still valuable enough to proceed as such, since you can use setPrototypeOf/proto for the proto case and .map for the mapper case if needed.

[bakkot]

For posterity, here's the slides from the stage 1 presentation.

[bakkot]

This achieved stage 2 at the May 2018 meeting!