Chapter 6

1. Asynchronous computations.
2. Try represents the erroneous case as an exception. Exceptions may not always be desirable in a functional context since they make sense only when we want to throw them. Functional programming discourages throwing exceptions since they are side effects. Hence, we have a more general type called Either that is capable of representing an alternative between any two values.
3. One way of representing dependency injection in functional programming is via the Reader type. It is an abstraction of the fact that a computation depends on some value and cannot be executed without it. Reader is basically a function. However, it has a more concise signature, and the concept of continuation with flatmap is applied to it the same way as to any other effect type.
4. Flatmap allows you to sequentially compose side-effecting computations that use effect types to represent side effects.