@throwsas you wrote is a Scala annotation which annotates the method and explicitly declares that this method may throw an exception of the declared type (or subclass). Annotations are meta-information about the declaration. As in Java, the annotation belongs immediately before the method declaration. You can read a little more about Scala annotations here:
http://www.scala-lang.org/node/106
, : Scala, Java, @throws , Java , , RuntimeException .
: Scala, throw new SlickException.