Compiler hang forever when arbitrary type in arrow closure

[deusaquilus]

Minimized code

When attempting a quoted match an arrow closure with arbitrary types in a macro:

tree.unseal.underlyingArgument.seal match {
    case '{ ($in: $tpe1) => ($out: $tpe2) } => Expr(out.toString)
}

E.g. when matching the following expression:

mac((x: String) => "anything")

The compiler hangs forever. It does not seem to be doing anything.

Expectation

The expression should match and compile property.

Code Sample

Code sample is available here:
https://github.com/deusaquilus/arrow_forever_bug

[nicolasstucki]

You should be using inline parameters rather than underlyingArgument.

[nicolasstucki]

Minimized to

import scala.quoted._

object Macro {
  inline def mac(): String = ${ macImpl() }
  def macImpl()(using qctx: QuoteContext): Expr[String] =
    '{(x: String) => "anything"} match
      case '{ (in: String) => ($out: $tpe2) } => Expr(out.toString)
      case _ => ???

}
import scala.quoted._

object Macro {
  inline def mac(): String = ${ macImpl() }
  def macImpl()(using qctx: QuoteContext): Expr[String] =
    '{(x: String) => "anything"} match
      case '{ (in: String) => ($out: $tpe2) } => Expr(out.toString)
      case _ => ???

}

import Macro._

@main def testOtherstuff() = { // hello
  mac()
}

[nicolasstucki]

Some side notes to improve the code

• import qctx.tasty.{given _, _} now can be import qctx.tasty._
• Use inline parameters instead of underlyingArgument

[deusaquilus]

You should be using inline parameters rather than underlyingArgument.

@nicolasstucki Like I mentioned before, we really, really, need to use underlyingArgument to get rid of the Inline nodes for the sake of our parser. I think many other macro framework authors will come to the same conclusion when they start writing complex pattern-matching code on tasty-reflect trees.