windowed.ts

function* windowed<T>(arr: T[], size: number) {
  for (let i = 0; i < arr.length; i++) {
    yield arr.slice(i, size + i);
  }
}

let thing = windowed([0, 1, 2, 3], 2);

for (let [a, b] of thing) {
  console.log(a, b);
}