ECMAScript proposal: Vampire operator

[tinkerscript]

The vampire operator (',..,') is extremely useful in imperative programming, as it allows to transfer properties from one object to another with mutation as a side effect.

Example:

const vampire = {};
const prey = {
  flag: true,
  count: 42,
  items: []
};

vampire ,.., prey;
console.log(vampire);
// {flag: true, count: 42, items: Array(0)}
console.log(prey);
// {}