org.json4s.JsonAST.scala Maven / Gradle / Ivy
/*
* Copyright 2009-2011 WorldWide Conferencing, LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.json4s
object JsonAST {
/**
* Concatenates a sequence of JValues.
*
* Example:
* concat(JInt(1), JInt(2)) == JArray(List(JInt(1), JInt(2)))
*
*/
def concat(xs: JValue*) = xs.foldLeft(JNothing: JValue)(_ ++ _)
object JValue extends Merge.Mergeable
/**
* Data type for JSON AST.
*/
sealed abstract class JValue extends Diff.Diffable with Product with Serializable {
type Values
/**
* Return unboxed values from JSON
*
* Example:
* JObject(JField("name", JString("joe")) :: Nil).values == Map("name" -> "joe")
*
*/
def values: Values
/**
* Return direct child elements.
*
* Example:
* JArray(JInt(1) :: JInt(2) :: Nil).children == List(JInt(1), JInt(2))
*
*/
def children: List[JValue] = this match {
case JObject(l) => l map (_._2)
case JArray(l) => l
case _ => Nil
}
/**
* Return nth element from JSON.
* Meaningful only to JArray, JObject and JField. Returns JNothing for other types.
*
* Example:
* JArray(JInt(1) :: JInt(2) :: Nil)(1) == JInt(2)
*
*/
def apply(i: Int): JValue = JNothing
/**
* Concatenate with another JSON.
* This is a concatenation monoid: (JValue, ++, JNothing)
*
* Example:
* JArray(JInt(1) :: JInt(2) :: Nil) ++ JArray(JInt(3) :: Nil) ==
* JArray(List(JInt(1), JInt(2), JInt(3)))
*
*/
def ++(other: JValue) = {
def append(value1: JValue, value2: JValue): JValue = (value1, value2) match {
case (JNothing, x) => x
case (x, JNothing) => x
case (JArray(xs), JArray(ys)) => JArray(xs ::: ys)
case (JArray(xs), v: JValue) => JArray(xs ::: List(v))
case (v: JValue, JArray(xs)) => JArray(v :: xs)
case (x, y) => JArray(x :: y :: Nil)
}
append(this, other)
}
/**
* When this [[org.json4s.JsonAST.JValue]] is a [[org.json4s.JsonAST.JNothing]] or a [[org.json4s.JsonAST.JNull]], this method returns [[scala.None]]
* When it has a value it will return [[scala.Some]]
*/
def toOption: Option[JValue] = this match {
case JNothing | JNull => None
case json => Some(json)
}
/**
* When this [[org.json4s.JsonAST.JValue]] is a [[org.json4s.JsonAST.JNothing]], this method returns [[scala.None]]
* When it has a value it will return [[scala.Some]]
*/
def toSome: Option[JValue] = this match {
case JNothing => None
case json => Some(json)
}
}
case object JNothing extends JValue {
type Values = None.type
def values = None
}
case object JNull extends JValue {
type Values = Null
def values = null
}
case class JString(s: String) extends JValue {
type Values = String
def values = s
}
trait JNumber
case class JDouble(num: Double) extends JValue with JNumber {
type Values = Double
def values = num
}
case class JDecimal(num: BigDecimal) extends JValue with JNumber {
type Values = BigDecimal
def values = num
}
case class JLong(num: Long) extends JValue with JNumber {
type Values = Long
def values = num
}
case class JInt(num: BigInt) extends JValue with JNumber {
type Values = BigInt
def values = num
}
case class JBool(value: Boolean) extends JValue {
type Values = Boolean
def values = value
}
object JBool {
val True = JBool(true)
val False = JBool(false)
}
case class JObject(obj: List[JField]) extends JValue {
type Values = Map[String, Any]
def values = obj.map { case (n, v) => (n, v.values) } toMap
override def equals(that: Any): Boolean = that match {
case o: JObject => obj.toSet == o.obj.toSet
case _ => false
}
override def hashCode = obj.toSet[JField].hashCode
}
case object JObject {
def apply(fs: JField*): JObject = JObject(fs.toList)
}
case class JArray(arr: List[JValue]) extends JValue {
type Values = List[Any]
def values = arr.map(_.values)
override def apply(i: Int): JValue = arr(i)
}
// JSet is set implementation for JValue.
// It supports basic set operations, like intersection, union and difference.
case class JSet(set: Set[JValue]) extends JValue {
type Values = Set[JValue]
def values = set
override def equals(o: Any): Boolean = o match {
case o: JSet => o.values == values
case _ => false
}
def intersect(o: JSet): JSet = JSet(o.values.intersect(values))
def union(o: JSet): JSet = JSet(o.values.union(values))
def difference(o: JSet): JSet = JSet(values.diff(o.values))
}
type JField = (String, JValue)
object JField {
def apply(name: String, value: JValue) = (name, value)
def unapply(f: JField): Option[(String, JValue)] = Some(f)
}
}