I understand that people love programming in classes, but I really want something like a stripped-down ES6. In particular, I want:

1. Lists and objects/dicts only; objects have no prototypes at all; objects have no first-class methods, but they can have functions as member variables, and those functions can close over other data in the object

2. All function and variable declaration is anonymous (as a consequence of 1); if you want to define a schema for an object, build a function that takes certain arguments and returns an object with the corresponding structure.

3. Coroutines/fibers/etc for async things; no promise/callback hell

4. Type annotations a la Python (not sure how this fits with 2 just yet)

EDIT: I did a bad job of emphasizing this, but syntax is important to me--I want something that looks like:

    var foo = {
        x: [1, 2, 3],
        y: (a, b, c) => {
            var sum = a + b + c;
            sum * sum
        },
    }

Whether or not you agree that syntax should be a relevant criteria is a different matter. :)