def apply()

in src/main/scala/com/twitter/iago/util/FlatJsonParser.scala [28:97]
62 lines of code
25 McCabe index (conditional complexity)

  def apply(json: String): Map[String, String] = {
    val map = new LinkedHashMap[String, String]
    var path: List[String] = Nil

    def add(value: String) = map(path.reverse.mkString("/")) = value

    def matchValue(start: Int): Int = json.charAt(start) match {
      case '{' => matchObject(start + 1)
      case '[' => matchArray(start + 1, 0)
      case '"' =>
        val end = findEndQuote(start + 1)
        add(json.substring(start, end + 1)) // include quotes
        end + 1
      case ' ' | '\t' | '\n' | '\r' | '\f' => matchValue(start + 1)
      case _ =>
        val end = findTokenEnd(start)
        add(json.substring(start, end))
        end
    }

    def findEndQuote(start: Int): Int = json.charAt(start) match {
      case '"' => start
      case '\\' => findEndQuote(start + 2)
      case _ => findEndQuote(start + 1)
    }

    def findTokenEnd(start: Int): Int = json.charAt(start) match {
      case ',' | ']' | '}' | ' ' | '\t' | '\n' | '\r' | '\f' => start
      case _ => findTokenEnd(start + 1)
    }

    def matchObject(start: Int): Int = json.charAt(start) match {
      case ' ' | '\t' | '\n' | '\r' | '\f' => matchObject(start + 1)
      case '}' => start + 1
      case '"' =>
        var end = findEndQuote(start + 1)
        path = json.substring(start + 1, end) :: path
        end = skipWs(end + 1)
        assert(json.charAt(end) == ':')
        end = skipWs(matchValue(end + 1))
        path = path.tail
        json.charAt(end) match {
          case ',' => matchObject(end + 1)
          case '}' => end + 1
          case c => throw new IllegalStateException("expected ',' or '}', found '" + c + "'")
        }
    }

    def matchArray(start: Int, index: Int): Int = json.charAt(start) match {
      case ' ' | '\t' | '\n' | '\r' | '\f' => matchArray(start + 1, index)
      case ']' => start + 1
      case _ =>
        path = index.toString :: path
        var end = skipWs(matchValue(start))
        path = path.tail
        json.charAt(end) match {
          case ',' => matchArray(end + 1, index + 1)
          case ']' => end + 1
          case c => throw new IllegalStateException("expected ',' or ']', found '" + c + "'")
        }
    }

    def skipWs(start: Int): Int = json.charAt(start) match {
      case ' ' | '\t' | '\n' | '\r' | '\f' => skipWs(start + 1)
      case _ => start
    }

    matchValue(0)
    map
  }