Suggestion: Surface - get list of derived classes about airframe HOT 3 OPEN

def Surface.derivedClassesWithMethods[T]: Seq[(Surface, Seq[MethodSurface])].

  def getSurface(quotes: Quotes)(classSymbol: quotes.reflect.Symbol): Option[Expr[Surface]] = {
    given q: Quotes = quotes
    import quotes.reflect.*
    val subclassType = classSymbol.typeRef
    Option.when(!classSymbol.flags.is(Flags.Trait) || !classSymbol.flags.is(Flags.Sealed)) {
      subclassType.asType match {
        case '[t] =>
          '{ Surface.of[t] }.asExprOf[Surface]
      }
    }
  }

  def enumerateSubclassesImpl[T: Type](using Quotes): Expr[List[Surface]] = {
    import quotes.reflect.*

    // Get the symbol of the sealed trait T
    val traitSymbol = TypeRepr.of[T].typeSymbol
    if (traitSymbol.flags.is(Flags.Sealed)) { // Ensure T is a sealed trait and get its subclasses
      // Recursive function to get all subclasses, including indirect ones
      def getAllSubclasses(symbol: Symbol): List[Symbol] = {
        symbol.children.flatMap { child =>
          child :: getAllSubclasses(child)
        }
      }

      // documentation seems unclear, it seems children already include indirect children, but not always
      val process = getAllSubclasses(traitSymbol).distinct

      val childrenExpr = process.flatMap(getSurface(summon[Quotes]))
      Expr.ofList(childrenExpr)
    } else {
      report.error(s"${traitSymbol.fullName} is not a sealed trait")
      '{ List.empty[Surface] }
    }
  }

  inline def enumerateSubclasses[T]: List[Surface] = ${ enumerateSubclassesImpl[T] }