let c = "c key";
let d = 3;
let b = 2;
let a = {
    "a b": 1,
    b,
    // [c] coverts to "c key"
    [c]: {
        // this coverts to d: 3
        d
    },
};
a.({
    a: ."a b",
    b: .b,
    ...(.'c key')
})