It's long been known that Haskell's type class system can be used to express computations which, being on the type level, are performed by the type checker and hence are performed at compile time. Scala's implicit definitions and parameters can be used to encode type classes, which suggests that we ought to be able to express the same sort of compile time computations in Scala too. In this talk I will confirm that suggestion and illustrate some of the surprisingly practical things this allows us to do.

It's long been known that Haskell's type class system can be used to express computations which, being on the type level, are performed by the type checker and hence are performed at compile time. Scala's implicit definitions and parameters can be used to encode type classes, which suggests that we ought to be able to express the same sort of compile time computations in Scala too. In this talk I will confirm that suggestion and illustrate some of the surprisingly practical things this allows us to do.