Create lenses for HList and use Generic (shapeless) to define Iso between case classes and HList

[julien-truffaut]

No description provided.

[julien-truffaut]

Any one knows how can I get an implicit of Generic.Aux[S, L] when S is a case class and L and HList?

@milessabin If you have a min, your help will be great :)

[puffnfresh]

@julien-truffaut I think it's something like this:

def toHList[A <: Product](a: A)(implicit g: Generic[A]): g.Repr = g.to(a)
def fromHList[A <: Product, H <: HList](a: H)(implicit g: Generic.Aux[A, H]): A = g.from(a)

[julien-truffaut]

@puffnfresh Thanks, I managed to create a method that generates a lens toward any element of a case class (mainly taken from shapeless lens) but I still need to use Generic.product on the case class to generate an implicit https://github.com/julien-truffaut/Monocle/blob/hlist-lens/examples/src/main/scala/monocle/HListExample.scala#L26

I also found another problem, overloading compose seems to cause an issue with complex lenses (see line 34).

[julien-truffaut]

Added lenses for HList and for any class that have an HList representation.
There are some issues between type inference and overloaded compose method, so I had to create an alias to compose which is restricted to lens composition.