With this chapter, we have already covered most of the Kotlin features for functional programming. We reviewed how to write shorter functions with single-expression functions, the different kind of parameters, how to extend our types with extension functions, and how to write natural and readable code with infix functions and operators. We also covered the basics of DSL authoring with type-safe builders and how to write efficient high-order functions. Last, but not least, we learned about recursion and corecursion.

In the next chapter, we will learn about Kotlin delegates.