Merge pull request #8698 from dotty-staging/fix-i8690

Fix #8690: the signature for product should come from expected type

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala

@@ -144,7 +144,7 @@ object PickledQuotes {
               case tp: TypeRef =>
                 typeSpliceMap.get(tp.symbol) match
                   case Some(t) if tp.typeSymbol.hasAnnotation(defn.InternalQuoted_QuoteTypeTagAnnot) => t
-                  case None => tp
+                  case _ => tp
               case _ => tp
             }
             mapOver(tp1)

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -2,7 +2,7 @@ sealed trait Exp[T]
 case class Fun[A, B](f: Exp[A => B]) extends Exp[A => B]
 
 class Test {
-  def eval[T](e: Exp[T]) = e match {
+  def eval(e: Fun[Int, Int]) = e match {
     case Fun(x: Fun[Int, Double]) => ???          // error
     case Fun(x: Exp[Int => String]) => ???        // error
   }

tests/neg-custom-args/isInstanceOf/enum-approx2.scala

@@ -0,0 +1 @@
+11: Pattern Match Exhaustivity: _: List

tests/patmat/exhaustive_heuristics.check

@@ -0,0 +1,7 @@
+class A
+class B
+
+def test(x: (A, B) | (B, A)) = x match {
+  case (u: A, v) => (u, v)
+  case (u: B, v) => (v, u)
+}

tests/patmat/i8690.scala

@@ -0,0 +1,7 @@
+class A
+class B
+
+def test(x: (A, B) | (B, A)) = x match {
+  case (u: A, v: B) => (u, v)
+  case (u: B, v: A) => (v, u)
+}

tests/patmat/i8690b.scala

@@ -0,0 +1 @@
+2: Pattern Match Exhaustivity: Some(_)

tests/patmat/i8708.check

@@ -0,0 +1,8 @@
+object Main {
+  def foo(x: Option[Int]): Int = x match {
+    case Some(n) if n % 2 == 0 => n
+    case None => 0
+  }
+
+  def main(args: Array[String]): Unit = println(foo(Some(1)))
+}

tests/patmat/i8708.scala

@@ -2,6 +2,7 @@
 11: Pattern Match Exhaustivity: Bar(_)
 23: Pattern Match Exhaustivity: (Qult(), Qult()), (Kult(_), Kult(_))
 49: Pattern Match Exhaustivity: _: Gp
+53: Pattern Match Exhaustivity: _: Gp
 59: Pattern Match Exhaustivity: Nil
 75: Pattern Match Exhaustivity: _: B
 87: Pattern Match Exhaustivity: _: C1

tests/patmat/patmatexhaust.check

@@ -0,0 +1,24 @@
+sealed trait Command {
+  type Reply
+}
+
+final case class Create() extends Command {
+  type Reply = CreateReply
+  val reply: Reply = CreateReply()
+}
+
+final case class Set() extends Command {
+  type Reply = SetReply
+  val reply: Reply = SetReply()
+}
+
+case class CreateReply()
+case class SetReply()
+
+def process[R](command: Command { type Reply = R }): R =
+  command match {
+    case create: Create => create.reply
+    case set: Set       => set.reply
+//                         ^
+// Warning: unreachable code
+  }

tests/patmat/t11457b.scala

@@ -0,0 +1,16 @@
+sealed abstract class Length
+
+object Length {
+  case class Num(n: Int) extends Length
+  case object StateColumn extends Length
+}
+
+import Length._
+
+case class Indent[T <: Length](length: T)
+
+def withIndent[T <: Length](indent: => Indent[_]): Unit =
+  indent match {
+    case Indent(Num(0)) => println("this")
+    case x              => println(x) // "unreachable"
+  }

tests/patmat/t11620b.scala

@@ -1 +1 @@
-8: Pattern Match Exhaustivity: TestB()
+8: Pattern Match Exhaustivity: _: Test

tests/patmat/t7631.check

@@ -1 +1 @@
-2: Pattern Match Exhaustivity: List(_)
+2: Pattern Match Exhaustivity: List(_, _: _*)