This thesis describes datatype-generic programming, what it is, and how it is done in Scala. The thesis covers ways of thinking about datatype-generic programming and today's tools and libraries for datatype-generic programming in Scala and summarize how to use them. A new library called perspective for datatype-generic programming with higher kinded data is presented. How these libraries, including perspective, work together with sum types is be covered. Benchmarks are presented on both runtime and compile time performance of perspective and other libraries. perspective manages to keep up in performance with other libraries while offering faster code at the expense of longer compile time if a developer opts into this. Finally, an example language-integrated query library built on perspective is described.Masteroppgave i informatikkINF399MAMN-INFMAMN-PRO
