HOAS quote pattern fails to match with def caprure

[nicolasstucki]

Compiler version

3.2

Minimized code

// Macro_1.scala
import scala.quoted.*

inline def test: String =  ${ testExpr }
def testExpr(using Quotes): Expr[String] =
  '{ def f(x: Int) = 1; f(3) } match
    case '{ def g(y: Int) = 1; $a(g): Int } =>  Expr(a.show)
    case _ => Expr("not matched")

// Test_2.scala
def app = test

Output

scalac -Xprint:inlining Macro_1.scala Test_2.scala

package <empty> {
  final lazy module val Test_2$package: Test_2$package = new Test_2$package()
  @SourceFile("t/Test_2.scala") final module class Test_2$package() extends
    Object() { this: Test_2$package.type =>
    private def writeReplace(): AnyRef =
      new scala.runtime.ModuleSerializationProxy(classOf[Test_2$package.type])
    def app: String = "not matched":String
  }
}

Expectation

The quote pattern should match and the result should be something like

    def app: String = "(g: Int => Int) => g(3)":String

[nicolasstucki]

Note that '{ def f(x: Int) = 1; identity(3) } does match.

[nicolasstucki]

This bug is probably in https://github.com/lampepfl/dotty/blob/main/compiler/src/scala/quoted/runtime/impl/QuoteMatcher.scala.

It might be related to the environment Env and ClosedPatternTerm.freePatternVars.

[nicolasstucki]

Or the way we recover the symbol of the arguments. The reference to g in $a(g) might be eta-expanded and we might be accidentally taking the symbol of this new lambda.

https://github.com/lampepfl/dotty/blob/main/compiler/src/scala/quoted/runtime/impl/QuoteMatcher.scala#L210