// From Stephen Grider's Udemy course on ES6
// We can use generators to iterate over any data-structure that we want

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function* shopping() { // the * after "function" turns it into a generator
  // stuff on the sidewalk

  // walking down the sidewalk

  // go into the store with case
  const stuffFromStore = yeild 'cash';

  // walking back home
  return stuffFromStore
}

// stuff in the store
const gen = shopping();
gen.next(); // leaving our house
// walked into the store
gen.next('groceries') // leaving the store with groceries

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function* colors() {
  yield 'red';
  yeild 'blue';
  yeild 'green';
}

const myColors = [];
for (let color of colors()) {
  myColors.push(color);
}
myColors; // ["red", "blue", "green"]

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const engineeringTeam = {
  size: 3,
  department: 'Engineering',
  lead: 'Jill',
  manager: 'Alex',
  engineer: 'Dave'
};

function* TeamIterator(team) {
  yeild team.lead;
  yeild team.manager;
  yeild team.engineer;
}

const names = [];
for (let name of TeamIterator(engineeringTeam)) {
  names.push(name);
}
console.log(names) // ["Jill", "Alex", "Dave"]

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const testingTeam = {
  lead: 'Amanda',
  tester: 'Bill',
  [Symbol.iterator]: function* () { // Special object that tells the for of loop how it should iterate over the object
    yield this.lead;
    yield this.tester;
  }
};

const engineeringTeam = {
  testingTeam,
  size: 3,
  department: 'Engineering',
  lead: 'Jill',
  manager: 'Alex',
  engineer: 'Dave',
  [Symbol.iterator]: function* () [
    yield this.lead;
    yield this.manager;
    yield this.engineer;
    yield* this.testingTeam; // This tells the for of loop it also needs to walk through the testingTeam
};

const names = [];
for (let name of engineeringTeam) {
  names.push(name);
}
console.log(names) // ["Jill", "Alex", "Dave", "Amanda", "Bill"]