Inference de-aliasses types in macros

[nicolasstucki]

Minimized example

import scala.quoted._

def myMacroImpl[T](using tp: Type[T])(using QuoteContext) = {
  val x = Expr(tp.show)
  '{ new TPrint[T]($x) }
}

class TPrint[T](override val toString: String)

inline def default[T]: TPrint[T] = ${ myMacroImpl[T] }

object Test extends App {

  type X = scala.Int with scala.Predef.String{}

  val s1: TPrint[X] = default[X]
  val s2: TPrint[X] = default

  println(s1)
  println(s2)

}

Output

Test.X
scala.Int & scala.Predef.String

Expectation

Both should be X

[nicolasstucki]

Originally used as implicit

...
implicit inline def default[T]: TPrint[T] = ${ myMacroImpl[T] }
def show[T](using tprint: Print[T]): String = tprint.toString

type X = scala.Int with scala.Predef.String{}
println(show[X])

[nicolasstucki]

@yilinwei

[nicolasstucki]

type X = scala.Int with scala.Predef.String{}
class TPrint[T](override val toString: String)
def default[T]: TPrint[T] = ???
val s1: TPrint[X] = default[X]
val s2: TPrint[X] = default // [(Int & String)]

[pweisenburger]

Note that this is not specific to macros but another instance of too eager dealiasing fixed by #14586.