Allow Target creation from Result[T] (#79)

1 files changed, 10 insertions, 1 deletions

diff --git a/core/src/main/scala/mill/define/Task.scala b/core/src/main/scala/mill/define/Task.scala
index 17392725..71a98fa7 100644
--- a/core/src/main/scala/mill/define/Task.scala
+++ b/core/src/main/scala/mill/define/Task.scala
@@ -40,7 +40,7 @@ object Target extends Applicative.Applyer[Task, Task, Result, Ctx]{
 
   implicit def apply[T](t: T): Target[T] = macro targetImpl[T]
 
-  implicit def apply[T](t: Result[T]): Target[T] = macro targetImpl[T]
+  implicit def apply[T](t: Result[T]): Target[T] = macro targetResultImpl[T]
 
   def apply[T](t: Task[T]): Target[T] = macro targetTaskImpl[T]
 
@@ -88,6 +88,15 @@ object Target extends Applicative.Applyer[Task, Task, Result, Ctx]{
     )
   }
 
+  def targetResultImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[Result[T]]): c.Expr[Target[T]] = {
+    import c.universe._
+    c.Expr[Target[T]](
+      mill.plugin.Cacher.wrapCached(c)(
+        q"new ${weakTypeOf[TargetImpl[T]]}(${Applicative.impl0[Task, T, Ctx](c)(t.tree).tree}, _root_.sourcecode.Enclosing())"
+      )
+    )
+  }
+
   def underlying[A](v: Task[A]) = v
   def mapCtx[A, B](t: Task[A])(f: (A, Ctx) => Result[B]) = t.mapDest(f)
   def zip() =  new Task.Task0(())