Merge pull request #3545 from dotty-staging/fix-3543

Fix #3543: compare extractor with TermRef instead of MethodType

Author: nicolasstucki

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

@@ -400,9 +400,9 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
         if (fun.symbol.owner == scalaSeqFactoryClass)
           projectSeq(pats)
         else
-          Prod(pat.tpe.stripAnnots, fun.tpe.widen, fun.symbol, projectSeq(pats) :: Nil, irrefutable(fun))
+          Prod(pat.tpe.stripAnnots, fun.tpe, fun.symbol, projectSeq(pats) :: Nil, irrefutable(fun))
       else
-        Prod(pat.tpe.stripAnnots, fun.tpe.widen, fun.symbol, pats.map(project), irrefutable(fun))
+        Prod(pat.tpe.stripAnnots, fun.tpe, fun.symbol, pats.map(project), irrefutable(fun))
     case Typed(pat @ UnApply(_, _, _), _) => project(pat)
     case Typed(expr, tpt) =>
       Typ(erase(expr.tpe.stripAnnots), true)

tests/patmat/3543.scala

@@ -0,0 +1,52 @@
+class Test {
+  class Foo {
+    def unapply(x: String): Option[String] = ???
+  }
+
+  def test(xs: List[String]): Unit = {
+    val Yes = new Foo
+    val No = new Foo
+
+    xs match {
+      case Yes(x) :: ls => println("Yes")
+      case No(y) :: ls => println("No")
+      case _ =>
+    }
+  }
+}
+
+class Test2 {
+  class Foo(x: Boolean) {
+    def unapply(y: String): Boolean = x
+  }
+
+  def test(xs: List[String]): Unit = {
+    val Yes = new Foo(true)
+    val No = new Foo(false)
+
+    xs match {
+      case No() :: ls => println("No")
+      case Yes() :: ls => println("Yes")
+      case _ =>
+    }
+  }
+}
+
+class Test3 {
+  import scala.util.matching.Regex
+
+  def main(args: Array[String]): Unit = {
+    foo("c" :: Nil, false)
+  }
+
+  def foo(remaining: List[String], inCodeBlock: Boolean): Unit = {
+    remaining match {
+      case CodeBlockEndRegex(before) :: ls =>
+      case SymbolTagRegex(name) :: ls if !inCodeBlock => println("OK")
+      case _ =>
+    }
+  }
+
+  val CodeBlockEndRegex = new Regex("(b)")
+  val SymbolTagRegex = new Regex("(c)")
+}