add patmat exhaustivity test examples

Author: liufengyun

examples/patmat-adt.scala

@@ -0,0 +1,33 @@
+object PatmatADT {
+  abstract sealed class Odd(x: Odd)
+
+  case class Good(x: Odd) extends Odd(x)
+  case class Bad(x: Odd) extends Odd(x)
+
+  def foo1a(x: Odd) = x match { // warning: Good(_: Bad), Bad(_: Good)
+    case Good(_: Good) => false
+    case Bad(_: Bad) => false
+  }
+
+  def foo1b(x: Odd) = x match {
+    case Good(_: Good) => false
+    case Bad(_: Bad) => false
+    case Good(_: Bad) => false
+    case Bad(_: Good) => false
+  }
+
+  def foo2(x: Option[Int]) = x match { // warning: Some(_: Int)
+    case Some(_: Double) => true
+    case None => true
+  }
+
+  def foo3a[T](x: Option[T]) = (x, x) match { // warning: (Some(_), Some(_)), (None, Some(_))
+    case (Some(_), None) => true
+    case (None, None) => true
+  }
+
+  def foo3b[T](x: Option[T]) = (x, x) match { // warning: (Some(_), Some(_)), (None, None)
+    case (Some(_), None) => true
+    case (None, Some(_)) => true
+  }
+}

examples/patmat-ortype.scala

@@ -0,0 +1,40 @@
+object PatmatOrType {
+ 
+  def foo1(x: Int | Double) = x match {
+    case _: Int => true
+    case _: Double => true
+  }
+
+  def foo2a(x: Int | Double | String) = x match { // _: String not matched
+    case _: Int => true
+    case _: Double => true
+  }
+
+  def foo2b(x: Int | Double | String) = x match {
+    case _: Int => true
+    case _: (Double | String) => true
+  }
+
+  def foo3(x: Option[Int | Double | String]) = x match { // warning: None, Some(_: String) not matched
+    case Some(_: Int) => true
+    case Some(_: Double) => true
+  }
+
+  def foo4(x: Option[Int | Double | String]) = x match {
+    case Some(_: Int) => true
+    case Some(_: Double) => true
+    case Some(_: String) => true
+    case None => false
+  }
+
+  def foo5a(x: Option[Int | Double | String]) = x match {
+    case Some(_: (Int | Double)) => true
+    case Some(_: String) => true
+    case None => false
+  }
+
+  def foo5b(x: Option[Int | Double | String]) = x match { // warning: Some(_: String) not matched
+    case Some(_: (Int | Double)) => true
+    case None => false
+  }
+}