plotly.Enumerate.scala Maven / Gradle / Ivy
package plotly
import shapeless.{ :+:, ::, CNil, Coproduct, Generic, HList, HNil, Inl, Inr, Strict }
sealed abstract class Enumerate[T] {
def apply(): Seq[T]
}
object Enumerate {
def apply[T](implicit enum: Enumerate[T]): Enumerate[T] = enum
private def instance[T](values: => Seq[T]): Enumerate[T] =
new Enumerate[T] {
def apply() = values
}
implicit val boolean: Enumerate[Boolean] =
instance(Seq(true, false))
implicit val hnil: Enumerate[HNil] =
instance(Seq(HNil))
implicit def hcons[H, T <: HList]
(implicit
head: Strict[Enumerate[H]],
tail: Enumerate[T]
): Enumerate[H :: T] =
instance {
for {
h <- head.value()
t <- tail()
} yield h :: t
}
implicit val cnil: Enumerate[CNil] =
instance(Seq())
implicit def ccons[H, T <: Coproduct]
(implicit
head: Strict[Enumerate[H]],
tail: Enumerate[T]
): Enumerate[H :+: T] =
instance(head.value().map(Inl(_)) ++ tail().map(Inr(_)))
implicit def generic[F, G]
(implicit
gen: Generic.Aux[F, G],
underlying: Strict[Enumerate[G]]
): Enumerate[F] =
instance(underlying.value().map(gen.from))
}