Polymorphic function values are one of the key abstractions in shapeless: they are crucial to enabling sequence-like operations such as map, flatMap and filter to be performed on HLists (data structures which combine the heterogeneous typing of tuples with list-like characteristics). Their encoding in Scala has been refined over a number of iterations, but remains a little heavyweight relative to the syntactic ease with which ordinary monomorphic functions or polymorphic methods can be defined. In this talk I will show how we can use macros to automatically promote polymorphic methods to polymorphic function values and how that improves the usability of shapeless.

No outline is available