fiber_lazy_enumerator

🔄 Implementing Generators and Lazy Enumerators

Use Fiber to build custom generators that yield sequence values on demand. Wrapping your Fiber in an Enumerator gives you built‑in lazy iteration, backpressure control, and composability with Ruby’s Enumerable API.

def fibonacci_generator
  Fiber.new do
    a, b = 0, 1
    loop do
      Fiber.yield a
      a, b = b, a + b
    end
  end
end

fib = Enumerator.new do |yielder|
  gen = fibonacci_generator
  loop { yielder << gen.resume }
end

# Lazy take first 10 fib numbers
iusages = fib.take(10)
puts usages.inspect # => [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]