一文详解JavaScript中生成器函数的妙用

function* simpleGenerator() {
  yield 1;
  yield 2;
  yield 3;
}

const generatorObject = simpleGenerator();

console.log(generatorObject.next().value); // 1
console.log(generatorObject.next().value); // 2
console.log(generatorObject.next().value); // 3

function* treeTraversal(tree) {
  yield tree.value;
  if (tree.children) {
    for (const child of tree.children) {
      yield* treeTraversal(child);
    }
  }
}

const tree = {
  value: 'root',
  children: [
    { value: 'child1' },
    { value: 'child2', children: [{ value: 'grandchild' }] }
  ]
};

for (const value of treeTraversal(tree)) {
  console.log(value);
}

function* flowControlGenerator() {
  const first = yield 'Need input 1';
  console.log(first);

  const second = yield 'Need input 2';
  console.log(second);

  return 'Done';
}

const controller = flowControlGenerator();

console.log(controller.next()); // { value: 'Need input 1', done: false }
console.log(controller.next('Input 1 provided')); // logs Input 1 provided
console.log(controller.next('Input 2 provided')); // logs Input 2 provided

function* asyncDataFetcher() {
  const data = yield fetchDataFromAPI(); // fetchDataFromAPI() is an async function
  console.log(data);
}

const fetcher = asyncDataFetcher();
fetcher.next().value.then((data) => {
  fetcher.next(data);
});

function* infiniteSequence() {
  let i = 0;
  while (true) {
    yield i++;
  }
}

const sequence = infiniteSequence();
console.log(sequence.next().value); // 0
console.log(sequence.next().value); // 1
// ... 无限执行下去，每次调用返回一个新值

function* generatorA() {
  const valueFromB = yield 'Data from A';
  console.log('Received data from B:', valueFromB);
}

function* generatorB(genA) {
  const valueFromA = genA.next().value;
  genA.next('Data from B');
  console.log('Received data from A:', valueFromA);
}

const genA = generatorA();
const genB = generatorB(genA);

genB.next();

function* batchProcessor(batchSize) {
  let data = null;
  while (data = fetchData(batchSize)) {
    yield processBatch(data);
  }
}

const processor = batchProcessor(100);
let processedData = processor.next();
while (!processedData.done) {
  console.log('Processed batch:', processedData.value);
  processedData = processor.next();
}

function* uniqueIdGenerator() {
  let id = Date.now();
  while (true) {
    yield id++;
  }
}

const ids = uniqueIdGenerator();
console.log(ids.next().value); // 一个基于时间戳的ID
console.log(ids.next().value); // 下一个ID