Update scala-library to 2.13.9 in 4.0

core/src/main/scala/org/json4s/FullTypeHints.scala

@@ -7,7 +7,7 @@ import org.json4s.reflect.Reflector
  */
 case class FullTypeHints(hints: List[Class[_]], override val typeHintFieldName: String = "jsonClass")
   extends TypeHints {
-  def hintFor(clazz: Class[_]) = Some(clazz.getName)
+  def hintFor(clazz: Class[_]): Some[String] = Some(clazz.getName)
   def classFor(hint: String, parent: Class[_]) = {
     Reflector
       .scalaTypeOf(hint)

core/src/main/scala/org/json4s/NoTypeHints.scala

@@ -5,7 +5,7 @@ package org.json4s
  */
 case object NoTypeHints extends TypeHints {
   val hints: List[Class[_]] = Nil
-  def hintFor(clazz: Class[_]) = None
-  def classFor(hint: String, parent: Class[_]) = None
+  def hintFor(clazz: Class[_]): None.type = None
+  def classFor(hint: String, parent: Class[_]): None.type = None
   override def shouldExtractHints(clazz: Class[_]) = false
 }

core/src/main/scala/org/json4s/ShortTypeHints.scala

@@ -5,7 +5,7 @@ package org.json4s
  */
 case class ShortTypeHints(hints: List[Class[_]], override val typeHintFieldName: String = "jsonClass")
   extends TypeHints {
-  def hintFor(clazz: Class[_]) =
+  def hintFor(clazz: Class[_]): Some[String] =
     Some(clazz.getName.substring(clazz.getName.lastIndexOf(".") + 1))
   def classFor(hint: String, parent: Class[_]) = hints find (hintFor(_).exists(_ == hint))
 }

jackson-core/src/main/scala/org/json4s/jackson/JValueDeserializerResolver.scala

@@ -7,7 +7,11 @@ import com.fasterxml.jackson.databind.{BeanDescription, DeserializationConfig, J
 private object JValueDeserializerResolver extends Deserializers.Base {
   private[this] val J_VALUE = classOf[JValue]
 
-  override def findBeanDeserializer(javaType: JavaType, config: DeserializationConfig, beanDesc: BeanDescription) = {
+  override def findBeanDeserializer(
+    javaType: JavaType,
+    config: DeserializationConfig,
+    beanDesc: BeanDescription
+  ): JValueDeserializer = {
     if (!J_VALUE.isAssignableFrom(javaType.getRawClass)) null
     else new JValueDeserializer(javaType.getRawClass)
   }

jackson-core/src/main/scala/org/json4s/jackson/JValueSerializerResolver.scala

@@ -6,7 +6,11 @@ import com.fasterxml.jackson.databind.{BeanDescription, JavaType, SerializationC
 
 private object JValueSerializerResolver extends Serializers.Base {
   private[this] val JVALUE = classOf[JValue]
-  override def findSerializer(config: SerializationConfig, theType: JavaType, beanDesc: BeanDescription) = {
+  override def findSerializer(
+    config: SerializationConfig,
+    theType: JavaType,
+    beanDesc: BeanDescription
+  ): JValueSerializer = {
     if (!JVALUE.isAssignableFrom(theType.getRawClass)) null
     else new JValueSerializer
   }

project/build.scala

@@ -55,7 +55,7 @@ object build {
 
   val Scala211 = "2.11.12"
   val Scala212 = "2.12.17"
-  val Scala213 = "2.13.8"
+  val Scala213 = "2.13.9"
   val Scala3 = "3.1.1"
 
   def json4sSettings(cross: Boolean) = mavenCentralFrouFrou ++ Def.settings(

scalap/src/main/scala/org/json4s/scalap/Result.scala

@@ -38,7 +38,7 @@ sealed abstract class Result[+Out, +A, +X] {
 case class Success[+Out, +A](out: Out, value: A) extends Result[Out, A, Nothing] {
   def error = throw new ScalaSigParserError("No error")
 
-  def toOption = Some(value)
+  def toOption: Some[A] = Some(value)
 
   def map[B](f: A => B): Result[Out, B, Nothing] = Success(out, f(value))
   def mapOut[Out2](f: Out => Out2): Result[Out2, A, Nothing] = Success(f(out), value)
@@ -53,12 +53,12 @@ sealed abstract class NoSuccess[+X] extends Result[Nothing, Nothing, X] {
   def out = throw new ScalaSigParserError("No output")
   def value = throw new ScalaSigParserError("No value")
 
-  def toOption = None
+  def toOption: None.type = None
 
-  def map[B](f: Nothing => B) = this
-  def mapOut[Out2](f: Nothing => Out2) = this
-  def map[Out2, B](f: (Nothing, Nothing) => (Out2, B)) = this
-  def flatMap[Out2, B](f: (Nothing, Nothing) => Result[Out2, B, Nothing]) = this
+  def map[B](f: Nothing => B): NoSuccess[X] = this
+  def mapOut[Out2](f: Nothing => Out2): NoSuccess[X] = this
+  def map[Out2, B](f: (Nothing, Nothing) => (Out2, B)): NoSuccess[X] = this
+  def flatMap[Out2, B](f: (Nothing, Nothing) => Result[Out2, B, Nothing]): NoSuccess[X] = this
   def orElse[Out2, B](other: => Result[Out2, B, Nothing]) = other
 }
 

scalap/src/main/scala/org/json4s/scalap/Rules.scala

@@ -153,5 +153,5 @@ trait StateRules {
 }
 
 trait RulesWithState extends Rules with StateRules {
-  val factory = this
+  val factory: RulesWithState = this
 }

scalap/src/main/scala/org/json4s/scalap/scalasig/Symbol.scala

@@ -13,9 +13,9 @@ trait Symbol extends Flags {
 
 case object NoSymbol extends Symbol {
   def name = "<no symbol>"
-  def parent = None
+  def parent: None.type = None
   def hasFlag(flag: Long) = false
-  def children = Nil
+  def children: Nil.type = Nil
 }
 
 abstract class ScalaSigSymbol extends Symbol {
@@ -59,7 +59,7 @@ abstract class SymbolInfoSymbol extends ScalaSigSymbol {
 
   def entry = symbolInfo.entry
   def name = symbolInfo.name
-  def parent = Some(symbolInfo.owner)
+  def parent: Some[Symbol] = Some(symbolInfo.owner)
   def hasFlag(flag: Long) = (symbolInfo.flags & flag) != 0L
 
   lazy val infoType = applyRule(parseEntry(typeEntry)(symbolInfo.info))