Generic Shape coproduct types reversed in section 2.4

[SamDM]

Near the end of section 2.4 there is the following example:

  sealed trait Shape
  final case class Rectangle(width: Double, height: Double) extends Shape
  final case class Circle(radius: Double) extends Shape

  val gen = Generic[Shape]

gen is supposed to be:

Generic[Shape]{type Repr = Rectangle :+: Circle :+: CNil} = ...

But when I try it, it is (note that Rectangle and Circle are in reversed order):

Generic[Shape]{type Repr = Circle :+: Rectangle :+: CNil} = ...

I am going through the book to learn about shapeless, I don't know if this is intended behavior of shapeless and a bug in the documentation or the other way around. Or does this only happen on my system? If this is a bug in shapeless I'll open an issue there (unless someone beats me to it).

I'm using scala 2.12.3 and shapeless 2.3.2, I'm compiling with sbt.

[SamDM]

Some more experimenting showed that the types are sorted by alphabet instead of order of occurence

[davegurnell]

Ah! Good to know. Thanks for the detective work! This must be intentional but I didn’t know it was the case.

…

On Mon, 11 Dec 2017 at 23:21, Sam De Meyer ***@***.***> wrote: Some more experimenting showed that the Types are sorted by alphabet instead of order of occurence — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#58 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAOI5xzcW3rzBTV7elCMJA5Q-1UpMVtIks5s_bjcgaJpZM4Q-LOg> .