Merge pull request #14201 from dotty-staging/fix-#14185

Remove reflect TypeApply TypeVars

Author: anatoliykmetyuk

compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

@@ -1882,13 +1882,13 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
 
     object AppliedType extends AppliedTypeModule:
       def unapply(x: AppliedType): (TypeRepr, List[TypeRepr]) =
-        (x.tycon, x.args)
+        (AppliedTypeMethods.tycon(x), AppliedTypeMethods.args(x))
     end AppliedType
 
     given AppliedTypeMethods: AppliedTypeMethods with
       extension (self: AppliedType)
-        def tycon: TypeRepr = self.tycon
-        def args: List[TypeRepr] = self.args
+        def tycon: TypeRepr = self.tycon.stripTypeVar
+        def args: List[TypeRepr] = self.args.mapConserve(_.stripTypeVar)
       end extension
     end AppliedTypeMethods
 

tests/pos-macros/i14185/Macro_1.scala

@@ -0,0 +1,60 @@
+import scala.quoted.*
+
+object Test {
+  inline def foo[A, M[_]]: Unit = ${ fooImpl[A, M] }
+
+  private def fooImpl[A, M[_]](
+      using
+      q: Quotes,
+      tc: Type[M],
+      pt: Type[A]
+    ): Expr[Unit] = {
+    import q.reflect.*
+
+    val ptpe = TypeRepr.of[A]
+    val neededGivenType = TypeRepr.of[M](using tc).appliedTo(ptpe)
+
+    val neededGiven: Option[Term] = Implicits.search(neededGivenType) match {
+      case suc: ImplicitSearchSuccess =>
+        Some(suc.tree)
+
+      case _ =>
+        None
+    }
+
+    neededGiven.map(_.show)
+
+    '{ () }
+  }
+}
+
+// ---
+
+/** Type level evidence that type `A` is not type `B`. */
+final class IsNot[A, B]() {
+  override val toString = "not"
+}
+
+object IsNot {
+  implicit def defaultEvidence[A, B]: IsNot[A, B] = new IsNot[A, B]()
+
+  @annotation.implicitAmbiguous("Could not prove type ${A} is not (IsNot) ${A}")
+  implicit def ambiguousEvidence1[A]: IsNot[A, A] = null
+  implicit def ambiguousEvidence2[A]: IsNot[A, A] = null
+}
+
+// ---
+
+sealed trait SomeTypeclass[T]
+
+object SomeTypeclass extends SomeTypeclassLowPrio {
+
+  given collection[T, Repr <: Iterable[T]](
+      using SomeTypeclass[T],
+      Repr IsNot Option[T]
+  ): SomeTypeclass[Repr] = new SomeTypeclass[Repr] {}
+}
+
+sealed trait SomeTypeclassLowPrio {
+  given int: SomeTypeclass[Int] = new SomeTypeclass[Int] {}
+}

tests/pos-macros/i14185/Test_2.scala

@@ -0,0 +1,2 @@
+def test =
+  Test.foo[Seq[Int], SomeTypeclass]