ParserTest.scala

import org.junit.Test
import util.parsing.combinator.JavaTokenParsers

class ParserTest extends JavaTokenParsers {
  @Test def aorb() {
    val json = """{ "address book": John }"""

    val r = parse(json)
    println(r)
  }

  def obj: Parser[Map[String, Any]] =
    "{" ~> repsep(member, ",") <~ "}" ^^ (Map() ++ _)

  def arr: Parser[List[Any]] =
    "[" ~> repsep(value, ",") <~ "]"

  def member: Parser[(String, Any)] =
    stringLiteral ~ ":" ~ value ^^ {
      case name ~ ":" ~ value => (name, value)
    }

  def value: Parser[Any] = obj | arr | stringLiteral | floatingPointNumber ^^ (_.toDouble) | "null" ^^ (x => null) | "true" ^^ (x => true) | "false" ^^ (x => false) | failure("illegal start of value")

  def parse(txt: String) = parseAll(obj, txt)
}