Ch4, Ex12

- In concurrent model, there is practically no flow control. Producer can freely generate the stream far ahead than actually needed by Sum at any point in time. While in lazy model its the other extreme where Producer only produces the next element when Sum explicitly asks for it. If we talk in terms of bounded buffer flow control then first case is where the buffer length is infinite whereas in second case its 0.

- It wouldn't have any effect. It'll behave same as the lazy version.