virtpatmat, hidden behind -Yvirtpatmat

at least one imminent TODO: undo hardwired generation of if/then/else,
and decide based on type whether to call flatMap/orElse or inline those
methods from Option

review by extempore

44 files changed, 307 insertions, 0 deletions

diff --git a/test/files/pos/virtpatmat_castbinder.flags b/test/files/pos/virtpatmat_castbinder.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_castbinder.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_castbinder.scala b/test/files/pos/virtpatmat_castbinder.scala
new file mode 100644
index 0000000000..be269638ce
--- /dev/null
+++ b/test/files/pos/virtpatmat_castbinder.scala
@@ -0,0 +1,15 @@
+class IntMap[+V]
+case class Bin[+T](m: IntMap[T]) extends IntMap[T]
+case class Tip[+T](x: T) extends IntMap[T]
+
+trait IntMapIterator[V, T] {
+  def valueOf(tip: Tip[V]): T
+  def pop: IntMap[V]
+
+  def next: T =
+    pop match {
+      case Bin(t@Tip(_)) => {
+        valueOf(t)
+      }
+    }
+}
\ No newline at end of file
diff --git a/test/files/pos/virtpatmat_exist1.flags b/test/files/pos/virtpatmat_exist1.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_exist1.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_exist1.scala b/test/files/pos/virtpatmat_exist1.scala
new file mode 100644
index 0000000000..6cad017b0b
--- /dev/null
+++ b/test/files/pos/virtpatmat_exist1.scala
@@ -0,0 +1,24 @@
+import annotation.unchecked.{ uncheckedVariance=> uV }
+import scala.collection.immutable.{ListMap, HashMap, ListSet, HashSet}
+
+object Test {
+  class HashMapCollision1[A, +B](var hash: Int, var kvs: ListMap[A, B @uV]) extends HashMap[A, B @uV]
+  class HashSetCollision1[A](var hash: Int, var ks: ListSet[A]) extends HashSet[A]
+
+  def splitArray[T](ad: Array[Iterable[T]]): Any =
+    ad(0) match {
+      case _: HashMapCollision1[_, _] | _: HashSetCollision1[_] => null
+    }
+
+    // without type ascription for the one in the body of the last flatmap of each alternative, type inference borks on the existentials
+    // def splitArray[T >: Nothing <: Any](ad: Array[Iterable[T]]): Any = { import OptionMatching._
+    //   runOrElse(ad.apply(0))(((x1: Iterable[T]) => (
+    //     or(((x4: Iterable[T]) => one(null)),
+    //       guard(x1.isInstanceOf[Iterable[T] with Test.HashMapCollision1[_,_]], x1.asInstanceOf[Iterable[T] with Test.HashMapCollision1[_,_]]).flatMap(((x2: Iterable[T] with Test.HashMapCollision1[_,_]) => one(x2))),
+    //       guard(x1.isInstanceOf[Test.HashSetCollision1[_]], x1.asInstanceOf[Iterable[T] with Test.HashSetCollision1[_]]).flatMap(((x3: Iterable[T] with Test.HashSetCollision1[_]) => one(x3)))): Option[Any]).orElse(
+    //     (zero: Option[Any])))
+    //   )
+    // }
+
+}
+
diff --git a/test/files/pos/virtpatmat_exist2.flags b/test/files/pos/virtpatmat_exist2.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_exist2.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_exist2.scala b/test/files/pos/virtpatmat_exist2.scala
new file mode 100644
index 0000000000..ee186074ab
--- /dev/null
+++ b/test/files/pos/virtpatmat_exist2.scala
@@ -0,0 +1,20 @@
+class ParseResult[+T]
+case class MemoEntry[+T](var r: Either[Nothing,ParseResult[_]])
+
+object Test {
+  def grow[T]: ParseResult[T] = (null: MemoEntry[T]) match {
+    case MemoEntry(Right(x: ParseResult[_])) => x.asInstanceOf[ParseResult[T]]
+  }
+
+  // what's the _$1 doing there?
+  // def grow[T >: Nothing <: Any]: ParseResult[T] = {
+  //   import OptionMatching._
+  //   runOrElse[MemoEntry[T], ParseResult[T]]((null: MemoEntry[T]))(((x1: MemoEntry[T]) =>
+  //     (MemoEntry.unapply[T](x1).flatMap[ParseResult[T]](((x4: Either[Nothing,ParseResult[_]]) =>
+  //       guard[Right[Nothing,ParseResult[_]]](x4.isInstanceOf[Right[Nothing,ParseResult[_]]], x4.asInstanceOf[Right[Nothing,ParseResult[_]]]).flatMap[ParseResult[T]](((cp3: Right[Nothing,ParseResult[_]]) =>
+  //         scala.Right.unapply[Nothing, ParseResult[_]](cp3).flatMap[ParseResult[T]](((x5: ParseResult[_]) =>
+  //           guard[ParseResult[_$1]](x5.ne(null), x5.asInstanceOf[ParseResult[_]]).flatMap[ParseResult[T]](((x6: ParseResult[_]) =>
+  //             one[ParseResult[T]](x6.asInstanceOf[ParseResult[T]]))))))))): Option[ParseResult[T]]
+  //     ).orElse[ParseResult[T]]((zero: Option[ParseResult[T]]))))
+  // }
+}
\ No newline at end of file
diff --git a/test/files/pos/virtpatmat_exist3.flags b/test/files/pos/virtpatmat_exist3.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_exist3.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_exist3.scala b/test/files/pos/virtpatmat_exist3.scala
new file mode 100644
index 0000000000..94385f32c9
--- /dev/null
+++ b/test/files/pos/virtpatmat_exist3.scala
@@ -0,0 +1,12 @@
+class ReferenceQueue[T] {
+  def wrapper(jref: ReferenceQueue[_]): ReferenceQueue[T] =
+    jref match {
+      case null => null
+    }
+
+  // def wrapper(jref: ReferenceQueue[_]): ReferenceQueue[T] = OptionMatching.runOrElse(jref)(((x1: ReferenceQueue[_]) =>
+  //   (OptionMatching.guard(null.==(x1), x1.asInstanceOf[ReferenceQueue[_]]).flatMap(((x2: ReferenceQueue[_]) =>
+  //     OptionMatching.one(null))): Option[ReferenceQueue[T]]).orElse(
+  //   (OptionMatching.zero: Option[ReferenceQueue[T]])))
+  // )
+}
\ No newline at end of file
diff --git a/test/files/pos/virtpatmat_gadt_array.flags b/test/files/pos/virtpatmat_gadt_array.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_gadt_array.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_gadt_array.scala b/test/files/pos/virtpatmat_gadt_array.scala
new file mode 100644
index 0000000000..f3332a897f
--- /dev/null
+++ b/test/files/pos/virtpatmat_gadt_array.scala
@@ -0,0 +1,15 @@
+import scala.collection.mutable._
+object Test {
+  def genericArrayOps[T](xs: Array[T]): ArrayOps[T] = xs match {
+    case x: Array[AnyRef]  => refArrayOps[AnyRef](x).asInstanceOf[ArrayOps[T]]
+    case null              => null
+  }
+  // def genericArrayOps[T >: Nothing <: Any](xs: Array[T]): scala.collection.mutable.ArrayOps[T]
+  //   = OptionMatching.runOrElse(xs)(((x1: Array[T]) =>
+  //     ((OptionMatching.guard(x1.isInstanceOf[Array[AnyRef]], x1.asInstanceOf[Array[T] with Array[AnyRef]]).flatMap(((x2: Array[T] with Array[AnyRef]) =>
+  //       OptionMatching.one(Test.this.refArrayOps[AnyRef](x2).asInstanceOf[scala.collection.mutable.ArrayOps[T]]))): Option[scala.collection.mutable.ArrayOps[T]]).orElse(
+  //     (OptionMatching.guard(null.==(x1), x1.asInstanceOf[Array[T]]).flatMap(((x3: Array[T]) =>
+  //         OptionMatching.one(null))): Option[scala.collection.mutable.ArrayOps[T]])): Option[scala.collection.mutable.ArrayOps[T]]).orElse((OptionMatching.zero: Option[scala.collection.mutable.ArrayOps[T]]))))
+
+  def refArrayOps[T <: AnyRef](xs: Array[T]): ArrayOps[T] = new ArrayOps.ofRef[T](xs)
+}
\ No newline at end of file
diff --git a/test/files/pos/virtpatmat_infer_single_1.flags b/test/files/pos/virtpatmat_infer_single_1.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_infer_single_1.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_infer_single_1.scala b/test/files/pos/virtpatmat_infer_single_1.scala
new file mode 100644
index 0000000000..b42af956cc
--- /dev/null
+++ b/test/files/pos/virtpatmat_infer_single_1.scala
@@ -0,0 +1,7 @@
+case class TypeBounds(a: Type, b: Type)
+class Type {
+  def bounds: TypeBounds = bounds match {
+    case TypeBounds(_: this.type, _: this.type) => TypeBounds(this, this)
+    case oftp                                   => oftp
+  }
+}
\ No newline at end of file
diff --git a/test/files/pos/virtpatmat_obj_in_case.flags b/test/files/pos/virtpatmat_obj_in_case.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/pos/virtpatmat_obj_in_case.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/pos/virtpatmat_obj_in_case.scala b/test/files/pos/virtpatmat_obj_in_case.scala
new file mode 100644
index 0000000000..496de4c12e
--- /dev/null
+++ b/test/files/pos/virtpatmat_obj_in_case.scala
@@ -0,0 +1,5 @@
+class ObjInCase {
+  0 match {
+    case _ => object o
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_alts.check b/test/files/run/virtpatmat_alts.check
new file mode 100644
index 0000000000..7a4ad0a741
--- /dev/null
+++ b/test/files/run/virtpatmat_alts.check
@@ -0,0 +1 @@
+OK 5
diff --git a/test/files/run/virtpatmat_alts.flags b/test/files/run/virtpatmat_alts.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_alts.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_alts.scala b/test/files/run/virtpatmat_alts.scala
new file mode 100644
index 0000000000..b7717524e2
--- /dev/null
+++ b/test/files/run/virtpatmat_alts.scala
@@ -0,0 +1,12 @@
+object Test extends App {
+  (true, true) match {
+    case (true, true) | (false, false) => 1
+  }
+
+  List(5) match {
+    case 1 :: Nil | 2 :: Nil  => println("FAILED")
+    case (x@(4 | 5 | 6)) :: Nil => println("OK "+ x)
+    case 7 :: Nil  => println("FAILED")
+    case Nil  => println("FAILED")
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_apply.check b/test/files/run/virtpatmat_apply.check
new file mode 100644
index 0000000000..e8e3b295e6
--- /dev/null
+++ b/test/files/run/virtpatmat_apply.check
@@ -0,0 +1 @@
+OK 2
diff --git a/test/files/run/virtpatmat_apply.flags b/test/files/run/virtpatmat_apply.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_apply.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_apply.scala b/test/files/run/virtpatmat_apply.scala
new file mode 100644
index 0000000000..b8776f4afb
--- /dev/null
+++ b/test/files/run/virtpatmat_apply.scala
@@ -0,0 +1,7 @@
+object Test extends App {
+ List(1, 2, 3) match {
+   case Nil => println("FAIL")
+   case x :: y :: xs if xs.length == 2 => println("FAIL")
+   case x :: y :: xs if xs.length == 1 => println("OK "+ y)
+ }
+}
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_casting.check b/test/files/run/virtpatmat_casting.check
new file mode 100644
index 0000000000..b11425edc8
--- /dev/null
+++ b/test/files/run/virtpatmat_casting.check
@@ -0,0 +1 @@
+List(1)
diff --git a/test/files/run/virtpatmat_casting.flags b/test/files/run/virtpatmat_casting.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_casting.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_casting.scala b/test/files/run/virtpatmat_casting.scala
new file mode 100644
index 0000000000..7c5e1c7117
--- /dev/null
+++ b/test/files/run/virtpatmat_casting.scala
@@ -0,0 +1,8 @@
+object Test extends App {
+  println(List(1,2,3) match {
+    case Nil => List(0)
+// since the :: extractor's argument must be a ::, there has to be a cast before its unapply is invoked
+    case x :: y :: z :: a :: xs => xs ++ List(x)
+    case x :: y :: z :: xs => xs ++ List(x)
+  })
+}
diff --git a/test/files/run/virtpatmat_literal.check b/test/files/run/virtpatmat_literal.check
new file mode 100644
index 0000000000..0eabe36713
--- /dev/null
+++ b/test/files/run/virtpatmat_literal.check
@@ -0,0 +1,3 @@
+OK
+OK
+OK
diff --git a/test/files/run/virtpatmat_literal.flags b/test/files/run/virtpatmat_literal.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_literal.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_literal.scala b/test/files/run/virtpatmat_literal.scala
new file mode 100644
index 0000000000..460811eba9
--- /dev/null
+++ b/test/files/run/virtpatmat_literal.scala
@@ -0,0 +1,21 @@
+object Test extends App {
+ 1 match {
+   case 2 => println("FAILED")
+   case 1 => println("OK")
+   case 1 => println("FAILED")
+ }
+
+ val one = 1
+ 1 match {
+   case 2 => println("FAILED")
+   case `one` => println("OK")
+   case 1 => println("FAILED")
+ }
+
+ 1 match {
+   case 2 => println("FAILED")
+   case Test.one => println("OK")
+   case 1 => println("FAILED")
+ }
+
+}
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_nested_lists.check b/test/files/run/virtpatmat_nested_lists.check
new file mode 100644
index 0000000000..d8263ee986
--- /dev/null
+++ b/test/files/run/virtpatmat_nested_lists.check
@@ -0,0 +1 @@
+2
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_nested_lists.flags b/test/files/run/virtpatmat_nested_lists.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_nested_lists.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_nested_lists.scala b/test/files/run/virtpatmat_nested_lists.scala
new file mode 100644
index 0000000000..fef74cea15
--- /dev/null
+++ b/test/files/run/virtpatmat_nested_lists.scala
@@ -0,0 +1,3 @@
+object Test extends App {
+  List(List(1), List(2)) match { case x :: (y :: Nil) :: Nil => println(y) }
+}
diff --git a/test/files/run/virtpatmat_npe.check b/test/files/run/virtpatmat_npe.check
new file mode 100644
index 0000000000..a0aba9318a
--- /dev/null
+++ b/test/files/run/virtpatmat_npe.check
@@ -0,0 +1 @@
+OK
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_npe.flags b/test/files/run/virtpatmat_npe.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_npe.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_npe.scala b/test/files/run/virtpatmat_npe.scala
new file mode 100644
index 0000000000..84a9276454
--- /dev/null
+++ b/test/files/run/virtpatmat_npe.scala
@@ -0,0 +1,10 @@
+class C {
+  class D
+  val values = new Array[AnyRef](10)
+  values(0) match {
+    case name: D => println("NOK: "+ name) // the outer check on D's outer should not cause a NPE
+    case null   => println("OK")
+  }
+}
+
+object Test extends C with App
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_partial.check b/test/files/run/virtpatmat_partial.check
new file mode 100644
index 0000000000..093020ce05
--- /dev/null
+++ b/test/files/run/virtpatmat_partial.check
@@ -0,0 +1,2 @@
+Map(a -> Some(1), b -> None)
+Map(a -> 1)
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_partial.flags b/test/files/run/virtpatmat_partial.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_partial.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_partial.scala b/test/files/run/virtpatmat_partial.scala
new file mode 100644
index 0000000000..d30944efb4
--- /dev/null
+++ b/test/files/run/virtpatmat_partial.scala
@@ -0,0 +1,73 @@
+object Test extends App {
+  val a = Map("a" -> Some(1), "b" -> None)
+  println(a)
+
+  val res = a collect {case (p, Some(a)) => (p, a)}
+
+  // should uncurry to:
+  // val res: Map[String,Int] = a.collect[(String, Int), Map[String,Int]](
+  //   new PartialFunction[(String, Option[Int]),(String, Int)]  {
+  //     def apply(x0_1: (String, Option[Int])): (String, Int) = MatchingStrategy.OptionMatchingStrategy.runOrElse[(String, Option[Int]), (String, Int)](x0_1)(
+  //       (x1: (String, Option[Int])) => {
+  //           val o9: Option[(String, Int)] = ({
+  //             val o8: Option[(String, Option[Int])] = Tuple2.unapply[String, Option[Int]](x1);
+  //             if (o8.isEmpty)
+  //               MatchingStrategy.OptionMatchingStrategy.zero
+  //             else
+  //               {
+  //                 val o7: Option[Some[Int]] = if (o8.get._2.isInstanceOf[Some[Int]])
+  //                   MatchingStrategy.OptionMatchingStrategy.one[Some[Int]](o8.get._2.asInstanceOf[Some[Int]])
+  //                 else
+  //                   MatchingStrategy.OptionMatchingStrategy.zero;
+  //                 if (o7.isEmpty)
+  //                   MatchingStrategy.OptionMatchingStrategy.zero
+  //                 else
+  //                   {
+  //                     val o6: Option[Int] = Some.unapply[Int](o7.get);
+  //                     if (o6.isEmpty)
+  //                       MatchingStrategy.OptionMatchingStrategy.zero
+  //                     else
+  //                       MatchingStrategy.OptionMatchingStrategy.one[(String, Int)]((o8.get._1, o6.get).asInstanceOf[(String, Int)])
+  //                   }
+  //               }
+  //           }: Option[(String, Int)]);
+  //           if (o9.isEmpty)
+  //             (MatchingStrategy.OptionMatchingStrategy.zero: Option[(String, Int)])
+  //           else
+  //             o9
+  //         })
+  //
+  //       def isDefinedAt(x_1: (String, Option[Int])): Boolean = MatchingStrategy.OptionMatchingStrategy.isSuccess[(String, Option[Int]), (String, Int)](x_1)(
+  //         (x1: (String, Option[Int])) => {
+  //           val o9: Option[(String, Int)] = ({
+  //             val o8: Option[(String, Option[Int])] = scala.Tuple2.unapply[String, Option[Int]](x1);
+  //             if (o8.isEmpty)
+  //               MatchingStrategy.OptionMatchingStrategy.zero
+  //             else
+  //               {
+  //                 val o7: Option[Some[Int]] = if (o8.get._2.isInstanceOf[Some[Int]])
+  //                   MatchingStrategy.OptionMatchingStrategy.one[Some[Int]](o8.get._2.asInstanceOf[Some[Int]]) // XXX
+  //                 else
+  //                   MatchingStrategy.OptionMatchingStrategy.zero;
+  //                 if (o7.isEmpty)
+  //                   MatchingStrategy.OptionMatchingStrategy.zero
+  //                 else
+  //                   {
+  //                     val o6: Option[Int] = scala.Some.unapply[Int](o7.get);
+  //                     if (o6.isEmpty)
+  //                       MatchingStrategy.OptionMatchingStrategy.zero
+  //                     else
+  //                       MatchingStrategy.OptionMatchingStrategy.one[(String, Int)](null.asInstanceOf[(String, Int)])
+  //                   }
+  //               }
+  //           }: Option[(String, Int)]);
+  //           if (o9.isEmpty)
+  //             (MatchingStrategy.OptionMatchingStrategy.zero: Option[(String, Int)])
+  //           else
+  //             o9
+  //     })
+  //   }
+  // )
+
+  println(res)
+}
diff --git a/test/files/run/virtpatmat_typed.check b/test/files/run/virtpatmat_typed.check
new file mode 100644
index 0000000000..cec2740d18
--- /dev/null
+++ b/test/files/run/virtpatmat_typed.check
@@ -0,0 +1 @@
+OK foo
diff --git a/test/files/run/virtpatmat_typed.flags b/test/files/run/virtpatmat_typed.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_typed.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_typed.scala b/test/files/run/virtpatmat_typed.scala
new file mode 100644
index 0000000000..cdd6d3c749
--- /dev/null
+++ b/test/files/run/virtpatmat_typed.scala
@@ -0,0 +1,7 @@
+object Test extends App {
+ ("foo": Any) match {
+   case x: Int => println("FAILED")
+   case x: String => println("OK "+ x)
+   case x: String => println("FAILED")
+ }
+}
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_unapply.check b/test/files/run/virtpatmat_unapply.check
new file mode 100644
index 0000000000..2b89b77d1e
--- /dev/null
+++ b/test/files/run/virtpatmat_unapply.check
@@ -0,0 +1,2 @@
+1
+6
diff --git a/test/files/run/virtpatmat_unapply.flags b/test/files/run/virtpatmat_unapply.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_unapply.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_unapply.scala b/test/files/run/virtpatmat_unapply.scala
new file mode 100644
index 0000000000..a6e71f3963
--- /dev/null
+++ b/test/files/run/virtpatmat_unapply.scala
@@ -0,0 +1,32 @@
+class IntList(val hd: Int, val tl: IntList)
+object NilIL extends IntList(0, null)
+object IntList {
+  def unapply(il: IntList): Option[(Int, IntList)] = if(il eq NilIL) None else Some(il.hd, il.tl)
+  def apply(x: Int, xs: IntList) = new IntList(x, xs)
+}
+
+object Test extends App {
+  IntList(1, IntList(2, NilIL)) match {
+    case IntList(a1, IntList(a2, IntList(a3, y))) => println(a1 + a2 + a3)
+    case IntList(x, y) => println(x)
+  }
+
+  IntList(1, IntList(2, IntList(3, NilIL))) match {
+    case IntList(a1, IntList(a2, IntList(a3, y))) => println(a1 + a2 + a3)
+    case IntList(x, y) => println(x)
+  }
+}
+
+// ((x1: IntList) => IntList.unapply(x1).flatMap(((x4: (Int, IntList)) => IntList.unapply(x4._2).flatMap(((x5: (Int, IntList)) => IntList.unapply(x5._2).flatMap(((x6: (Int, IntList)) => implicitly[Predef.MatchingStrategy[Option]].success(Predef.println(x4._1.+(x5._1).+(x6._1))))))))).orElse(IntList.unapply(x1).flatMap(((x7: (Int, IntList)) => implicitly[scala.Predef.MatchingStrategy[Option]].success(Predef.println(x7._1))))).orElse(implicitly[scala.Predef.MatchingStrategy[Option]].fail))(IntList.apply(1, IntList.apply(2, IntList.apply(3, null))))
+
+/*
+  ((x1: IntList) =>
+    IntList.this.unapply(x1).flatMap[Int](((x4: (Int, IntList)) =>
+      IntList.this.unapply(x4._2).flatMap[Int](((x5: (Int, IntList)) =>
+        IntList.this.unapply(x5._2).flatMap[Int](((x6: (Int, IntList)) =>
+          Predef.this.implicitly[scala.Predef.MatchingStrategy[Option]](scala.this.Predef.OptionMatching).success[Int](x6._1))))))).orElse[Int](
+    IntList.this.unapply(x1).flatMap[Int](((x7: (Int, IntList)) =>
+      Predef.this.implicitly[scala.Predef.MatchingStrategy[Option]](scala.this.Predef.OptionMatching).success[Int](x7._1)))).orElse[Int](
+    Predef.this.implicitly[scala.Predef.MatchingStrategy[Option]](scala.this.Predef.OptionMatching).fail)
+  ).apply(IntList.apply(1, null))
+*/
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_unapplyseq.check b/test/files/run/virtpatmat_unapplyseq.check
new file mode 100644
index 0000000000..62f9457511
--- /dev/null
+++ b/test/files/run/virtpatmat_unapplyseq.check
@@ -0,0 +1 @@
+6
\ No newline at end of file
diff --git a/test/files/run/virtpatmat_unapplyseq.flags b/test/files/run/virtpatmat_unapplyseq.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_unapplyseq.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_unapplyseq.scala b/test/files/run/virtpatmat_unapplyseq.scala
new file mode 100644
index 0000000000..270fa9045a
--- /dev/null
+++ b/test/files/run/virtpatmat_unapplyseq.scala
@@ -0,0 +1,5 @@
+object Test extends App {
+  List(1,2,3) match {
+    case Seq(x, y, z) => println(x * y * z)
+  }
+}
\ No newline at end of file