Scala - Early initialization block after extends

EarlyInitializationAfterExtends.scala

trait Logger {
  def log(msg: String)
  def info(msg: String) { log("INFO: " + msg) }
  def warn(msg: String) { log("WARN: " + msg) }
  def severe(msg: String) { log("SEVERE: " + msg) }
}

trait FileLogger extends Logger {
  val filename: String
  
  val out = new java.io.PrintWriter(filename)
  out.println("# " + new java.util.Date().toString)
  
  def log(msg: String) { out.println(msg); out.flush() }
}

class SavingsAccount extends { // Early definition block after extends
  val filename = "savings.log"
} with FileLogger {
  // SavingsAccount implementation
}

val acct = new SavingsAccount
acct.info("hey!")