sbt/tasks/Node.scala

44 lines
1.3 KiB
Scala

package sbt
import Node._
import Types._
trait Node[A[_], T]
{
type Inputs <: MList[Id]
type Results <: Inputs#Map[Result]
def inputs: Inputs#Map[A]
def unitDependencies: Iterable[A[_]]
def work(results: Results, units: Iterable[Incomplete]): Either[A[T], T]
}
object Node
{
type Result[T] = Either[Throwable, T]
def pure[T](f: => T): PureNode[T]= map[Id, T, MNil](MNil, Nil)((_,_) => f)
def map[A[_], T, Inputs0 <: MList[Id]](inputs0: Inputs0#Map[A], deps0: Iterable[A[_]])(work0: (Inputs0#Map[Result], Iterable[Incomplete]) => T):
Node[A,T] { type Inputs = Inputs0; type Results = Inputs0#Map[Result] } =
new Node[A,T] {
type Inputs = Inputs0
type Results = Inputs0#Map[Result]
def inputs = inputs0
def unitDependencies = deps0
def work(results: Results, units: Iterable[Incomplete]) = Right(work0(results, units))
}
type PureNode[T] = Node[Id, T] { type Inputs = MNil; type Results = MNil }
type WorkResult[T] = Either[Id[T], T]
val pureResults = new ~>[PureNode, WorkResult] { def apply[T](t: PureNode[T] ) = t.work( MNil, Nil ) }
}
object Test
{
val a = pure(3)
val b = pure(true)
val c = pure("asdf")
val i3 = a :^: b :^: c :^: MNil
val d = map[PureNode, String, i3.Map[Id]](i3, Nil) { case (a :^: b :^: c :^: MNil, Seq()) => a + " " + b + " " + c }
}