Migrate over to the new `Task`/`Target`/`Command` split

1 files changed, 134 insertions, 0 deletions

diff --git a/core/src/main/scala/forge/define/Task.scala b/core/src/main/scala/forge/define/Task.scala
new file mode 100644
index 00000000..a78fcaa7
--- /dev/null
+++ b/core/src/main/scala/forge/define/Task.scala
@@ -0,0 +1,134 @@
+package forge.define
+
+import forge.define.Applicative.Applyable
+import forge.eval.PathRef
+import forge.util.Args
+import scala.language.experimental.macros
+import scala.reflect.macros.blackbox.Context
+
+abstract class Task[+T] extends Task.Ops[T] with Applyable[T]{
+  /**
+    * What other Targets does this Target depend on?
+    */
+  val inputs: Seq[Task[_]]
+
+  /**
+    * Evaluate this target
+    */
+  def evaluate(args: Args): T
+
+  /**
+    * Even if this target's inputs did not change, does it need to re-evaluate
+    * anyway?
+    */
+  def sideHash: Int = 0
+}
+
+class Target[+T](t: Task[T]) extends Task[T] {
+  val inputs = Seq(t)
+  def evaluate(args: Args) = args[T](0)
+}
+class Command[+T](t: Task[T]) extends Task[T] {
+  val inputs = Seq(t)
+  def evaluate(args: Args) = args[T](0)
+}
+object Task extends Applicative.Applyer[Task, Task, Args]{
+
+  def underlying[A](v: Task[A]) = v
+
+  trait Cacher extends forge.define.Cacher[Task, Target]{
+    def wrapCached[T](t: Task[T]): Target[T] = new Target(t)
+  }
+  class Target0[T](t: T) extends Task[T]{
+    lazy val t0 = t
+    val inputs = Nil
+    def evaluate(args: Args)  = t0
+  }
+  def apply[T](t: Task[T]): Target[T] = macro Cacher.impl0[Task, T]
+
+  def cmd[T](t: T): Command[T] = macro targetCommandImpl[T]
+  def targetCommandImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T]): c.Expr[Command[T]] = {
+    import c.universe._
+    c.Expr[Command[T]](
+      q"new forge.define.Command(${Applicative.impl[Task, T, Args](c)(t).tree})"
+    )
+  }
+  def task[T](t: T): Task[T] = macro Applicative.impl[Task, T, Args]
+
+  def apply[T](t: T): Target[T] = macro targetCachedImpl[T]
+
+  def targetCachedImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T]): c.Expr[Target[T]] = {
+    c.Expr[Target[T]](
+      forge.define.Cacher.wrapCached(c)(
+        Applicative.impl[Task, T, Args](c)(t).tree
+      )
+    )
+  }
+
+  abstract class Ops[+T]{ this: Task[T] =>
+    def map[V](f: T => V) = new Task.Mapped(this, f)
+    def mapDest[V](f: (T, Args) => V) = new Task.MappedDest(this, f)
+
+    def filter(f: T => Boolean) = this
+    def withFilter(f: T => Boolean) = this
+    def zip[V](other: Task[V]) = new Task.Zipped(this, other)
+
+  }
+
+  def traverse[T](source: Seq[Task[T]]) = {
+    new Traverse[T](source)
+  }
+  class Traverse[+T](val inputs: Seq[Task[T]]) extends Task[Seq[T]]{
+    def evaluate(args: Args) = {
+      for (i <- 0 until args.length)
+      yield args(i).asInstanceOf[T]
+    }
+
+  }
+  class Mapped[+T, +V](source: Task[T], f: T => V) extends Task[V]{
+    def evaluate(args: Args) = f(args(0))
+    val inputs = List(source)
+  }
+  class MappedDest[+T, +V](source: Task[T], f: (T, Args) => V) extends Task[V]{
+    def evaluate(args: Args) = f(args(0), args)
+    val inputs = List(source)
+  }
+  class Zipped[+T, +V](source1: Task[T], source2: Task[V]) extends Task[(T, V)]{
+    def evaluate(args: Args) = (args(0), args(1))
+    val inputs = List(source1, source2)
+  }
+
+  def path(path: ammonite.ops.Path) = new Path(path)
+  class Path(path: ammonite.ops.Path) extends Task[PathRef]{
+    def handle = PathRef(path)
+    def evaluate(args: Args) = handle
+    override def sideHash = handle.hashCode()
+    val inputs = Nil
+  }
+
+
+  def mapCtx[A, B](t: Task[A])(f: (A, Args) => B) = t.mapDest(f)
+  def zip() =  new Task.Target0(())
+  def zip[A](a: Task[A]) = a.map(Tuple1(_))
+  def zip[A, B](a: Task[A], b: Task[B]) = a.zip(b)
+  def zip[A, B, C](a: Task[A], b: Task[B], c: Task[C]) = new Task[(A, B, C)]{
+    val inputs = Seq(a, b, c)
+    def evaluate(args: Args) = (args[A](0), args[B](1), args[C](2))
+  }
+  def zip[A, B, C, D](a: Task[A], b: Task[B], c: Task[C], d: Task[D]) = new Task[(A, B, C, D)]{
+    val inputs = Seq(a, b, c, d)
+    def evaluate(args: Args) = (args[A](0), args[B](1), args[C](2), args[D](3))
+  }
+  def zip[A, B, C, D, E](a: Task[A], b: Task[B], c: Task[C], d: Task[D], e: Task[E]) = new Task[(A, B, C, D, E)]{
+    val inputs = Seq(a, b, c, d, e)
+    def evaluate(args: Args) = (args[A](0), args[B](1), args[C](2), args[D](3), args[E](4))
+  }
+  def zip[A, B, C, D, E, F](a: Task[A], b: Task[B], c: Task[C], d: Task[D], e: Task[E], f: Task[F]) = new Task[(A, B, C, D, E, F)]{
+    val inputs = Seq(a, b, c, d, e, f)
+    def evaluate(args: Args) = (args[A](0), args[B](1), args[C](2), args[D](3), args[E](4), args[F](5))
+  }
+  def zip[A, B, C, D, E, F, G](a: Task[A], b: Task[B], c: Task[C], d: Task[D], e: Task[E], f: Task[F], g: Task[G]) = new Task[(A, B, C, D, E, F, G)]{
+    val inputs = Seq(a, b, c, d, e, f, g)
+    def evaluate(args: Args) = (args[A](0), args[B](1), args[C](2), args[D](3), args[E](4), args[F](5), args[G](6))
+  }
+}