Bits of .NET

🔄 Generators = Iterable Functions

Normal functions run completely. Generators pause and resume. Infinite lists, async flows, custom iteration.

📝 Generator Basics

// Generator function
function* numberGenerator() {
    yield 1;
    yield 2;
    yield 3;
}

// Using generator
const gen = numberGenerator();
console.log(gen.next()); // { value: 1, done: false }
console.log(gen.next()); // { value: 2, done: false }
console.log(gen.next()); // { value: 3, done: false }
console.log(gen.next()); // { value: undefined, done: true }

// For-of loop
for (const num of numberGenerator()) {
    console.log(num); // 1, 2, 3
}

// Spread operator
const numbers = [...numberGenerator()]; // [1, 2, 3]

// Infinite sequence
function* infiniteNumbers() {
    let i = 0;
    while (true) {
        yield i++;
    }
}

const infinite = infiniteNumbers();
console.log(infinite.next().value); // 0
console.log(infinite.next().value); // 1
console.log(infinite.next().value); // 2

🎯 Advanced Generators

// Fibonacci sequence
function* fibonacci() {
    let a = 0, b = 1;
    while (true) {
        yield a;
        [a, b] = [b, a + b];
    }
}

const fib = fibonacci();
console.log(fib.next().value); // 0
console.log(fib.next().value); // 1
console.log(fib.next().value); // 1
console.log(fib.next().value); // 2
console.log(fib.next().value); // 3

// Yield with return value
function* generatorWithReturn() {
    yield 1;
    yield 2;
    return 3; // Ends generator
}

const gen2 = generatorWithReturn();
console.log(gen2.next()); // { value: 1, done: false }
console.log(gen2.next()); // { value: 2, done: false }
console.log(gen2.next()); // { value: 3, done: true }

💡 Generator Use Cases

• Infinite sequences
• Lazy evaluation
• State machines
• Async flows
• Data pagination