mirror of https://github.com/sbt/sbt.git
44 lines
1.0 KiB
Scala
44 lines
1.0 KiB
Scala
/* sbt -- Simple Build Tool
|
|
* Copyright 2010 Mark Harrah
|
|
*/
|
|
package sbt
|
|
|
|
import Types._
|
|
|
|
sealed trait MList[+M[_]]
|
|
{
|
|
// For converting MList[Id] to an HList
|
|
// This is useful because type inference doesn't work well with Id
|
|
type Raw <: HList
|
|
def down(implicit ev: M ~> Id): Raw
|
|
|
|
type Map[N[_]] <: MList[N]
|
|
def map[N[_]](f: M ~> N): Map[N]
|
|
|
|
def toList: List[M[_]]
|
|
}
|
|
final case class MCons[H, +T <: MList[M], +M[_]](head: M[H], tail: T) extends MList[M]
|
|
{
|
|
type Raw = H :+: tail.Raw
|
|
def down(implicit f: M ~> Id): Raw = HCons(f(head), tail.down(f))
|
|
|
|
type Map[N[_]] = MCons[H, tail.Map[N], N]
|
|
def map[N[_]](f: M ~> N) = MCons( f(head), tail.map(f) )
|
|
|
|
def :^: [N[X] >: M[X], G](g: N[G]): MCons[G, MCons[H, T, N], N] = MCons(g, this)
|
|
|
|
def toList = head :: tail.toList
|
|
}
|
|
sealed class MNil extends MList[Nothing]
|
|
{
|
|
type Raw = HNil
|
|
def down(implicit f: Nothing ~> Id) = HNil
|
|
|
|
type Map[N[_]] = MNil
|
|
def map[N[_]](f: Nothing ~> N) = MNil
|
|
|
|
def :^: [M[_], H](h: M[H]): MCons[H, MNil, M] = MCons(h, this)
|
|
|
|
def toList = Nil
|
|
}
|
|
object MNil extends MNil |