Quote pattern spliced expression has wrong type

[nicolasstucki]

minimized code

def expr(e: Expr[Any]) = {
  val '{ $x: $t } = e
  '{
    val a: $t = $x
   }
}

30 |        val a: $t = $x
   |                     ^
   |                     Found:    scala.quoted.Expr[Any](x)
   |                     Required: quoted.Expr[t.T]

expectation

x should have type quoted.Expr[t.T]

[anatoliykmetyuk]

Also note the compiler crash described in #6997 when trying to cast, I think these two can be different issues

[nicolasstucki]

Actually the issue is type avoidance which seems to do exactly what it should.

val $1$: (scala.quoted.Expr[Any], scala.quoted.Type[_]) = e:quoted.Expr[Any](e) @unchecked match {  ...  }
val x: scala.quoted.Expr[Any] = $1$._1
val t: scala.quoted.Type[_] = $1$._2
'{ ... }

The correct way to express this is to write the complete pattern match

e match {
  case '{ $x: $t } => 
    '{ val a: $t = $x }
}

[nicolasstucki]

With new syntax it is possible to unpack on one line

e match case '{ $x: $t } =>
'{ val a: $t = $x }

[nicolasstucki]

The best we can do is to emit an error if a val pattern used type splices and guide the user to rewrite it as a match.