Added test case for LMS inspired HK code.

Closes #94.

Author: odersky

tests/pos/i94-nada.scala

@@ -0,0 +1,43 @@
+import scala.language.higherKinds
+
+trait Base {
+  type Rep[T]
+}
+
+trait BaseExp extends Base {
+  type Rep[T] = Exp[T]
+  case class Exp[T](v: T)
+}
+
+trait BaseStr extends Base {
+  type Rep[T] = String
+}
+
+trait BaseDirect extends Base {
+  type Rep[T] = T
+}
+
+trait Test1 {
+  trait Monad[X] {
+    def x: X
+  }
+  sealed abstract class Either[A,B]
+  case class Left[A,B](x: A) extends Either[A,B] with Monad[A]
+  case class Right[A,B](x: B) extends Either[A,B] with Monad[B]
+  def flatMap[X,Y,M[X]<:Monad[X]](m: M[X], f: X => M[Y]): M[Y] = f(m.x)
+  println(flatMap(Left(1), {x: Int => Left(x)}))
+}
+trait Test2 {
+  trait Monad[X] {
+    def x: X
+  }
+  sealed abstract class Either[A,B]
+  case class Left[A,B](x: A) extends Either[A,B] with Monad[A]
+  case class Right[A,B](x: B) extends Either[A,B] with Monad[B]
+  def flatMap[X,Y,M[X]](m: M[X], f: X => M[Y]): M[Y]
+  println(flatMap(Left(1), {x: Int => Left(x)}))
+}
+trait Test3 {
+  def flatMap[X,Y,M[X]](m: M[X], f: X => M[Y]): M[Y]
+  println(flatMap(Some(1), {x: Int => Some(x)}))
+}