ron-aharoni / deriving-meetup

Code and slides on type class derivation in Scala 3

deriving-meetup

Code and slides on type class derivation in Scala 3. See also Blog and Video (Hebrew).

deriving-meetup's Issues

derivation for generic Map case class field?

Hi, thanks for this boost getting started with type class derivation! I have a product case classes with various Map types and of course I can easily define a derive for each higher order kind, such as:

// not too too bad...
given mapRandIntStr: Random[Map[Int, String]] with { def produce: Map[Int, String] = Map(0 -> "test") }

// if only it were this easy....
given mapRand[K: Random, V: Random]: Random[Map[K, V]] = Random.derived

I understand Map type isn't really a (nested) product, and so you'd probably have to get at the underlying list of Tuple in order to properly derive it (actually this is mentioned subtly here). At the same time, writing a given for every single variation of Map[K,V] is a bit nightmare-ish too!

Do you have any thoughts on how this could be done, treating Map[K,V] as a nested Random as succinctly as possible?