Lecture
This lecture introduces the concept of type classes in Scala, which are generic traits with given instances for specific types. The instructor explains how to implement type classes, such as Ordering, and provides examples with Int, String, and Rational types. The lecture covers retroactive extension, conditional instances for lists, recursive implicit resolution, and extension methods. It concludes with a summary highlighting the advantages of type classes over class extension and their role in ad-hoc polymorphism.