gistfile1.scala

scala> import net.liftweb.json._
import net.liftweb.json._

scala> import net.liftweb.json.JsonDSL._
import net.liftweb.json.JsonDSL._

scala> implicit val formats = DefaultFormats
formats: net.liftweb.json.DefaultFormats.type = net.liftweb.json.DefaultFormats$@158faa04

scala> val json = """[1,2,3,4,5]"""
json: java.lang.String = [1,2,3,4,5]

scala> parse(json).extract[List[Int]]
res1: List[Int] = List(1, 2, 3, 4, 5)

scala> parse(json).extract[Set[Int]]
res2: Set[Int] = Set(5, 1, 2, 3, 4)