>>673 javascript
const take = n => function*(iterable) {
const iterator = iterable[Symbol.iterator]();
for (let i = 0; i < n; i++) {
const {value, done} = iterator.next();
if (done) break;
yield value;
}
};
const fibo = function*() {
const memo = [0n, 1n];
const fib = n => n in memo ? memo[n] : memo[n] = fib(n - 2) + fib(n - 1);
for(let i = 0; ; i++) yield fib(i);
}();

console.log([...take(10)(fibo)]);
結果：
[0n, 1n, 1n, 2n, 3n, 5n, 8n, 13n, 21n, 34n]