Read ahead and learn about transactional memory (Section XXXXXXXXXXThen read up on STM Haskell [HMPH05]. Explain how monads facilitate the serialization of updates to locations shared between threads....

Read ahead and learn about transactional memory (Section 13.4.4). Then read up on STM Haskell [HMPH05]. Explain how monads facilitate the serialization of updates to locations shared between threads. We have seen that Lisp and ML include such imperative features as assignment and iteration. How important are these? What do languages like Haskell give up (conversely, what do they gain) by insisting on a purely functional programming style? In a similar vein, what do you think of attempts in several recent imperative languages (notably Python and C#— see Sidebar 11.6) to facilitate functional programming with function constructors and unlimited extent?