Domain-specific languages, or DSLs, provide a convenient, declarative, type-safe syntax for solving a specific type of problem. DSLs written in Kotlin have been applied to problems such as declaring HTML layouts, building mobile UI frameworks, and defining HTTP routes for web servers. We've seen that, in Kotlin, DSLs are primarily composed of functions and function literals with a receiver. Through these mechanisms, we can build type-safe builders that are useful for building a human-readable, declarative syntax. We've also explored how Kotlin features such as extension functions, infix notation, and custom annotations can improve the usability and readability of our custom DSLs. Finally, we learned how to apply these features to the construction of our own domain-specific language in order to define a mobile UI.
In the next chapter, we'll dive into functional...