In this introspective talk we will take a look at Servant, a DSL in Haskell, that allows its users to specify the entirety of a web API in the type system. We'll see how Servant leverages values as types in order to generate clients in various languages, derive a mock server, and generate type-checked documentation - all without having to implement the API itself. We'll analyze the consequences of treating values as types and see what we can learn and hopefully bring back to the JVM.

Presented by Jonathan Curran

Sponsored by The InSource Group