JsonPath for Json4s
import JsonPath._
val ast = parse(strJson)
val name = ast s_\ "$.object.array[4].name" // String value
val age = ast i_\ "$.object.array[4].age" // Integer value
val tall = ast b_\ "$.object.array[4].am_i_tall" // Boolean value
val maybeChildren = ast i_\? "$.object.array[4].childrenCount" // Option[Integer] value