the essence of tcpoly inference + test cases

fixes to check files and removed nonapplicable test case Tuple2 impl,
but commented out so that we can bootstrap whitespace...

1 files changed, 26 insertions, 0 deletions

diff --git a/test/files/pos/tcpoly_infer_ticket716.scala b/test/files/pos/tcpoly_infer_ticket716.scala
new file mode 100644
index 0000000000..cfba07fa43
--- /dev/null
+++ b/test/files/pos/tcpoly_infer_ticket716.scala
@@ -0,0 +1,26 @@
+
+trait Functor[F[_]] {
+  def fmap[A,B](fun: A=>B, arg:F[A]): F[B]
+}
+object Functor{
+  implicit val ListFunctor: Functor[List] = new Functor[List] {
+    def fmap[A, B](f: A => B, arg: List[A]):List[B] = arg map f
+  }
+
+  final class OOFunctor[F[_],A](arg:F[A])(implicit ftr: Functor[F]) {
+    def fmap[B](fun: A=>B):F[B] = ftr.fmap(fun,arg)
+  }
+
+  //breaks if uncommented
+  implicit def lifttoOO[F[_],A](arg:F[A])(implicit ftr: Functor[F]) = new OOFunctor[F,A](arg)(ftr)
+
+  //works if uncommented
+  //implicit def liftListtoOO[A](arg:List[A]):OOFunctor[List,A] = new OOFunctor[List,A](arg)
+}
+
+object GeneralLiftingDemo extends Application {
+  import Functor._
+  val l = List(1,2,3)
+  val res = l fmap( 1+) // TODO: should not need explicit call to lifttoOO
+  println("OO : " + res )
+}
\ No newline at end of file