Scale By the Bay 2020

We've all seen many Monad tutorials, and maybe a few on Functors, but Applicative is lesser known, which is a shame because it has some super powers. In this talk I'll tell the origin story of applicative, and show that once fully understood, it is a very powerful tool in your functional programming toolkit. The talk begins with a quick introduction to pure functional programming with effects, for beginners in the audience. Next we'll look at the original paper in which applicative programming with effects is described. The code will be translated from the original Haskell to Scala, and we can see we can solve problems first with Monads, then more flexibly and elegantly with Applicative. Finally, we'll look at how Applicative plays its part in the much lauded traverse function.