A Fistful of Monads Table of contents Zippers We've seen how monads can be used to take values with contexts and apply them to functions and how using >>= or do notation allows us to focus on the values themselves while the context gets handled for us. We've met the Maybe monad and seen how it adds a context of possible failure to values. We've learned about the list monad and saw how it lets us easily introduce non-determinism into our programs. We've also learned how to work in the IO monad, even before we knew what a monad was! In this chapter, we're going to learn about a few other monads. We'll see how they can make our programs clearer by letting us treat all sorts of values as monadic ones. Exploring a few monads more will also solidify our intuition for monads. The monads that we'll be exploring are all part of the mtl package. A Haskell pack...