js generator

1function* fibonacci() {
2  var a = yield 1;
3  yield a * 2;
4}
5
6var it = fibonacci();
7console.log(it);          // "Generator {  }"
8console.log(it.next());   // 1
9console.log(it.send(10)); // 20
10console.log(it.close());  // undefined
11console.log(it.next());   // throws StopIteration (as the generator is now closed)
12

1function* name([param[, param[, ... param]]]) {
2   statements
3}
4