Enumerator#feed examples

enumerator.rb

class Integer
  def stream(by: 1)
    Enumerator.new Float::INFINITY do |yielder|
      int = self

      loop do
        fed = yielder.yield(int)
        int += fed if fed
        int += by
      end
    end
  end
end

flow = 42.stream
flow.next #=> 42
flow.next #=> 43
flow.feed 100 #=> nil
flow.next #=> 144
flow.rewind
flow.next #=> 42

class Enumerator
  def self.repeatedly(&block)
    raise ArgumentError, 'Block required' unless block_given?

    Enumerator.new Float::INFINITY do |yielder|
      loop do
        fed = yielder.yield block.call
        block = fed if fed
      end
    end
  end
end

enum = Enumerator.repeatedly { 42 }
enum.next #=> 42
enum.first 4 #=> [42, 42, 42, 42]

enum.feed ->{ rand 42 }
enum.next #=> 11 # now random
enum.first 4 #=> [32, 4, 1, 28]