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/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package scala
package reflect
import scala.annotation.{implicitNotFound, nowarn}
import scala.collection.mutable.{ArrayBuilder, ArraySeq}
/** A `Manifest[T]` is an opaque descriptor for type T. Its supported use
* is to give access to the erasure of the type as a `Class` instance, as
* is necessary for the creation of native `Arrays` if the class is not
* known at compile time.
*
* The type-relation operators `<:<` and `=:=` should be considered
* approximations only, as there are numerous aspects of type conformance
* which are not yet adequately represented in manifests.
*
* Example usages:
* {{{
* def arr[T] = new Array[T](0) // does not compile
* def arr[T](implicit m: Manifest[T]) = new Array[T](0) // compiles
* def arr[T: Manifest] = new Array[T](0) // shorthand for the preceding
*
* // Methods manifest and optManifest are in [[scala.Predef]].
* def isApproxSubType[T: Manifest, U: Manifest] = manifest[T] <:< manifest[U]
* isApproxSubType[List[String], List[AnyRef]] // true
* isApproxSubType[List[String], List[Int]] // false
*
* def methods[T: Manifest] = manifest[T].runtimeClass.getMethods
* def retType[T: Manifest](name: String) =
* methods[T] find (_.getName == name) map (_.getGenericReturnType)
*
* retType[Map[_, _]]("values") // Some(scala.collection.Iterable)
* }}}
*/
@nowarn("""cat=deprecation&origin=scala\.reflect\.ClassManifest(DeprecatedApis.*)?""")
@implicitNotFound(msg = "No Manifest available for ${T}.")
// TODO undeprecated until Scala reflection becomes non-experimental
// @deprecated("use scala.reflect.ClassTag (to capture erasures) or scala.reflect.runtime.universe.TypeTag (to capture types) or both instead", "2.10.0")
trait Manifest[T] extends ClassManifest[T] with Equals {
override def typeArguments: List[Manifest[_]] = Nil
override def arrayManifest: Manifest[Array[T]] =
Manifest.classType[Array[T]](arrayClass[T](runtimeClass), this)
override def canEqual(that: Any): Boolean = that match {
case _: Manifest[_] => true
case _ => false
}
/** Note: testing for erasure here is important, as it is many times
* faster than <:< and rules out most comparisons.
*/
override def equals(that: Any): Boolean = that match {
case m: Manifest[_] => (m canEqual this) && (this.runtimeClass == m.runtimeClass) && (this <:< m) && (m <:< this)
case _ => false
}
override def hashCode = this.runtimeClass.##
}
/** The object `Manifest` defines factory methods for manifests.
* It is intended for use by the compiler and should not be used in client code.
*/
// TODO undeprecated until Scala reflection becomes non-experimental
// @deprecated("use scala.reflect.ClassTag (to capture erasures), scala.reflect.runtime.universe.TypeTag (to capture types) or both instead", "2.10.0")
object Manifest {
/* Forward all the public members of ManifestFactory, since this object used
* to be a `private val Manifest = ManifestFactory` in the package object. It
* was moved here because it needs to be in the same file as `trait Manifest`
* defined above.
*/
def valueManifests: List[AnyValManifest[_]] =
ManifestFactory.valueManifests
val Byte: ManifestFactory.ByteManifest = ManifestFactory.Byte
val Short: ManifestFactory.ShortManifest = ManifestFactory.Short
val Char: ManifestFactory.CharManifest = ManifestFactory.Char
val Int: ManifestFactory.IntManifest = ManifestFactory.Int
val Long: ManifestFactory.LongManifest = ManifestFactory.Long
val Float: ManifestFactory.FloatManifest = ManifestFactory.Float
val Double: ManifestFactory.DoubleManifest = ManifestFactory.Double
val Boolean: ManifestFactory.BooleanManifest = ManifestFactory.Boolean
val Unit: ManifestFactory.UnitManifest = ManifestFactory.Unit
val Any: Manifest[scala.Any] = ManifestFactory.Any
val Object: Manifest[java.lang.Object] = ManifestFactory.Object
val AnyRef: Manifest[scala.AnyRef] = ManifestFactory.AnyRef
val AnyVal: Manifest[scala.AnyVal] = ManifestFactory.AnyVal
val Null: Manifest[scala.Null] = ManifestFactory.Null
val Nothing: Manifest[scala.Nothing] = ManifestFactory.Nothing
/** Manifest for the singleton type `value.type`. */
def singleType[T <: AnyRef](value: AnyRef): Manifest[T] =
ManifestFactory.singleType[T](value)
/** Manifest for the class type `clazz[args]`, where `clazz` is
* a top-level or static class.
* @note This no-prefix, no-arguments case is separate because we
* it's called from ScalaRunTime.boxArray itself. If we
* pass varargs as arrays into this, we get an infinitely recursive call
* to boxArray. (Besides, having a separate case is more efficient)
*/
def classType[T](clazz: Predef.Class[_]): Manifest[T] =
ManifestFactory.classType[T](clazz)
/** Manifest for the class type `clazz`, where `clazz` is
* a top-level or static class and args are its type arguments. */
def classType[T](clazz: Predef.Class[T], arg1: Manifest[_], args: Manifest[_]*): Manifest[T] =
ManifestFactory.classType[T](clazz, arg1, args: _*)
/** Manifest for the class type `clazz[args]`, where `clazz` is
* a class with non-package prefix type `prefix` and type arguments `args`.
*/
def classType[T](prefix: Manifest[_], clazz: Predef.Class[_], args: Manifest[_]*): Manifest[T] =
ManifestFactory.classType[T](prefix, clazz, args: _*)
def arrayType[T](arg: Manifest[_]): Manifest[Array[T]] =
ManifestFactory.arrayType[T](arg)
/** Manifest for the abstract type `prefix # name`. `upperBound` is not
* strictly necessary as it could be obtained by reflection. It was
* added so that erasure can be calculated without reflection. */
def abstractType[T](prefix: Manifest[_], name: String, upperBound: Predef.Class[_], args: Manifest[_]*): Manifest[T] =
ManifestFactory.abstractType[T](prefix, name, upperBound, args: _*)
/** Manifest for the unknown type `_ >: L <: U` in an existential. */
def wildcardType[T](lowerBound: Manifest[_], upperBound: Manifest[_]): Manifest[T] =
ManifestFactory.wildcardType[T](lowerBound, upperBound)
/** Manifest for the intersection type `parents_0 with ... with parents_n`. */
def intersectionType[T](parents: Manifest[_]*): Manifest[T] =
ManifestFactory.intersectionType[T](parents: _*)
}
// TODO undeprecated until Scala reflection becomes non-experimental
// @deprecated("use type tags and manually check the corresponding class or type instead", "2.10.0")
@nowarn("""cat=deprecation&origin=scala\.reflect\.ClassManifest(DeprecatedApis.*)?""")
@SerialVersionUID(1L)
abstract class AnyValManifest[T <: AnyVal](override val toString: String) extends Manifest[T] with Equals {
override def <:<(that: ClassManifest[_]): Boolean =
(that eq this) || (that eq Manifest.Any) || (that eq Manifest.AnyVal)
override def canEqual(other: Any) = other match {
case _: AnyValManifest[_] => true
case _ => false
}
override def equals(that: Any): Boolean = this eq that.asInstanceOf[AnyRef]
@transient
override val hashCode = System.identityHashCode(this)
}
/** `ManifestFactory` defines factory methods for manifests.
* It is intended for use by the compiler and should not be used in client code.
*
* Unlike `Manifest`, this factory isn't annotated with a deprecation warning.
* This is done to prevent avalanches of deprecation warnings in the code that calls methods with manifests.
* Why so complicated? Read up the comments for `ClassManifestFactory`.
*/
@nowarn("""cat=deprecation&origin=scala\.reflect\.ClassManifest(DeprecatedApis.*)?""")
object ManifestFactory {
def valueManifests: List[AnyValManifest[_]] =
List(Byte, Short, Char, Int, Long, Float, Double, Boolean, Unit)
@SerialVersionUID(1L)
final private[reflect] class ByteManifest extends AnyValManifest[scala.Byte]("Byte") {
def runtimeClass: Class[java.lang.Byte] = java.lang.Byte.TYPE
@inline override def newArray(len: Int): Array[Byte] = new Array[Byte](len)
override def newWrappedArray(len: Int): ArraySeq[Byte] = new ArraySeq.ofByte(new Array[Byte](len))
override def newArrayBuilder(): ArrayBuilder[Byte] = new ArrayBuilder.ofByte()
override def unapply(x: Any): Option[Byte] = {
x match {
case d: Byte => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Byte
}
val Byte: ByteManifest = new ByteManifest
@SerialVersionUID(1L)
final private[reflect] class ShortManifest extends AnyValManifest[scala.Short]("Short") {
def runtimeClass: Class[java.lang.Short] = java.lang.Short.TYPE
@inline override def newArray(len: Int): Array[Short] = new Array[Short](len)
override def newWrappedArray(len: Int): ArraySeq[Short] = new ArraySeq.ofShort(new Array[Short](len))
override def newArrayBuilder(): ArrayBuilder[Short] = new ArrayBuilder.ofShort()
override def unapply(x: Any): Option[Short] = {
x match {
case d: Short => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Short
}
val Short: ShortManifest = new ShortManifest
@SerialVersionUID(1L)
final private[reflect] class CharManifest extends AnyValManifest[scala.Char]("Char") {
def runtimeClass: Class[java.lang.Character] = java.lang.Character.TYPE
@inline override def newArray(len: Int): Array[Char] = new Array[Char](len)
override def newWrappedArray(len: Int): ArraySeq[Char] = new ArraySeq.ofChar(new Array[Char](len))
override def newArrayBuilder(): ArrayBuilder[Char] = new ArrayBuilder.ofChar()
override def unapply(x: Any): Option[Char] = {
x match {
case d: Char => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Char
}
val Char: CharManifest = new CharManifest
@SerialVersionUID(1L)
final private[reflect] class IntManifest extends AnyValManifest[scala.Int]("Int") {
def runtimeClass: Class[java.lang.Integer] = java.lang.Integer.TYPE
@inline override def newArray(len: Int): Array[Int] = new Array[Int](len)
override def newWrappedArray(len: Int): ArraySeq[Int] = new ArraySeq.ofInt(new Array[Int](len))
override def newArrayBuilder(): ArrayBuilder[Int] = new ArrayBuilder.ofInt()
override def unapply(x: Any): Option[Int] = {
x match {
case d: Int => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Int
}
val Int: IntManifest = new IntManifest
@SerialVersionUID(1L)
final private[reflect] class LongManifest extends AnyValManifest[scala.Long]("Long") {
def runtimeClass: Class[java.lang.Long] = java.lang.Long.TYPE
@inline override def newArray(len: Int): Array[Long] = new Array[Long](len)
override def newWrappedArray(len: Int): ArraySeq[Long] = new ArraySeq.ofLong(new Array[Long](len))
override def newArrayBuilder(): ArrayBuilder[Long] = new ArrayBuilder.ofLong()
override def unapply(x: Any): Option[Long] = {
x match {
case d: Long => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Long
}
val Long: LongManifest = new LongManifest
@SerialVersionUID(1L)
final private[reflect] class FloatManifest extends AnyValManifest[scala.Float]("Float") {
def runtimeClass: Class[java.lang.Float] = java.lang.Float.TYPE
@inline override def newArray(len: Int): Array[Float] = new Array[Float](len)
override def newWrappedArray(len: Int): ArraySeq[Float] = new ArraySeq.ofFloat(new Array[Float](len))
override def newArrayBuilder(): ArrayBuilder[Float] = new ArrayBuilder.ofFloat()
override def unapply(x: Any): Option[Float] = {
x match {
case d: Float => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Float
}
val Float: FloatManifest = new FloatManifest
@SerialVersionUID(1L)
final private[reflect] class DoubleManifest extends AnyValManifest[scala.Double]("Double") {
def runtimeClass: Class[java.lang.Double] = java.lang.Double.TYPE
@inline override def newArray(len: Int): Array[Double] = new Array[Double](len)
override def newWrappedArray(len: Int): ArraySeq[Double] = new ArraySeq.ofDouble(new Array[Double](len))
override def newArrayBuilder(): ArrayBuilder[Double] = new ArrayBuilder.ofDouble()
override def unapply(x: Any): Option[Double] = {
x match {
case d: Double => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Double
}
val Double: DoubleManifest = new DoubleManifest
@SerialVersionUID(1L)
final private[reflect] class BooleanManifest extends AnyValManifest[scala.Boolean]("Boolean") {
def runtimeClass: Class[java.lang.Boolean] = java.lang.Boolean.TYPE
@inline override def newArray(len: Int): Array[Boolean] = new Array[Boolean](len)
override def newWrappedArray(len: Int): ArraySeq[Boolean] = new ArraySeq.ofBoolean(new Array[Boolean](len))
override def newArrayBuilder(): ArrayBuilder[Boolean] = new ArrayBuilder.ofBoolean()
override def unapply(x: Any): Option[Boolean] = {
x match {
case d: Boolean => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Boolean
}
val Boolean: BooleanManifest = new BooleanManifest
@SerialVersionUID(1L)
final private[reflect] class UnitManifest extends AnyValManifest[scala.Unit]("Unit") {
def runtimeClass: Class[java.lang.Void] = java.lang.Void.TYPE
@inline override def newArray(len: Int): Array[Unit] = new Array[Unit](len)
override def newWrappedArray(len: Int): ArraySeq[Unit] = new ArraySeq.ofUnit(new Array[Unit](len))
override def newArrayBuilder(): ArrayBuilder[Unit] = new ArrayBuilder.ofUnit()
override protected def arrayClass[T](tp: Class[_]): Class[Array[T]] =
if (tp eq runtimeClass) classOf[Array[scala.runtime.BoxedUnit]].asInstanceOf[Class[Array[T]]]
else super.arrayClass(tp)
override def unapply(x: Any): Option[Unit] = {
x match {
case d: Unit => Some(d)
case _ => None
}
}
private def readResolve(): Any = Manifest.Unit
}
val Unit: UnitManifest = new UnitManifest
private[this] val ObjectTYPE = classOf[java.lang.Object]
private[this] val NothingTYPE = classOf[scala.runtime.Nothing$]
private[this] val NullTYPE = classOf[scala.runtime.Null$]
@SerialVersionUID(1L)
final private class AnyManifest extends PhantomManifest[scala.Any](ObjectTYPE, "Any") {
override def newArray(len: Int) = new Array[scala.Any](len)
override def <:<(that: ClassManifest[_]): Boolean = (that eq this)
private def readResolve(): Any = Manifest.Any
}
val Any: Manifest[scala.Any] = new AnyManifest
@SerialVersionUID(1L)
final private class ObjectManifest extends PhantomManifest[java.lang.Object](ObjectTYPE, "Object") {
override def newArray(len: Int) = new Array[java.lang.Object](len)
override def <:<(that: ClassManifest[_]): Boolean = (that eq this) || (that eq Any)
private def readResolve(): Any = Manifest.Object
}
val Object: Manifest[java.lang.Object] = new ObjectManifest
val AnyRef: Manifest[scala.AnyRef] = Object.asInstanceOf[Manifest[scala.AnyRef]]
@SerialVersionUID(1L)
final private class AnyValPhantomManifest extends PhantomManifest[scala.AnyVal](ObjectTYPE, "AnyVal") {
override def newArray(len: Int) = new Array[scala.AnyVal](len)
override def <:<(that: ClassManifest[_]): Boolean = (that eq this) || (that eq Any)
private def readResolve(): Any = Manifest.AnyVal
}
val AnyVal: Manifest[scala.AnyVal] = new AnyValPhantomManifest
@SerialVersionUID(1L)
final private class NullManifest extends PhantomManifest[scala.Null](NullTYPE, "Null") {
override def newArray(len: Int) = new Array[scala.Null](len)
override def <:<(that: ClassManifest[_]): Boolean =
(that ne null) && (that ne Nothing) && !(that <:< AnyVal)
private def readResolve(): Any = Manifest.Null
}
val Null: Manifest[scala.Null] = new NullManifest
@SerialVersionUID(1L)
final private class NothingManifest extends PhantomManifest[scala.Nothing](NothingTYPE, "Nothing") {
override def newArray(len: Int) = new Array[scala.Nothing](len)
override def <:<(that: ClassManifest[_]): Boolean = (that ne null)
private def readResolve(): Any = Manifest.Nothing
}
val Nothing: Manifest[scala.Nothing] = new NothingManifest
@SerialVersionUID(1L)
final private class SingletonTypeManifest[T <: AnyRef](value: AnyRef) extends Manifest[T] {
lazy val runtimeClass: Class[_ <: AnyRef] = value.getClass
override lazy val toString = value.toString + ".type"
}
/** Manifest for the singleton type `value.type`. */
def singleType[T <: AnyRef](value: AnyRef): Manifest[T] =
new SingletonTypeManifest[T](value)
/** Manifest for the class type `clazz[args]`, where `clazz` is
* a top-level or static class.
* @note This no-prefix, no-arguments case is separate because we
* it's called from ScalaRunTime.boxArray itself. If we
* pass varargs as arrays into this, we get an infinitely recursive call
* to boxArray. (Besides, having a separate case is more efficient)
*/
def classType[T](clazz: Predef.Class[_]): Manifest[T] =
new ClassTypeManifest[T](None, clazz, Nil)
/** Manifest for the class type `clazz`, where `clazz` is
* a top-level or static class and args are its type arguments. */
def classType[T](clazz: Predef.Class[T], arg1: Manifest[_], args: Manifest[_]*): Manifest[T] =
new ClassTypeManifest[T](None, clazz, arg1 :: args.toList)
/** Manifest for the class type `clazz[args]`, where `clazz` is
* a class with non-package prefix type `prefix` and type arguments `args`.
*/
def classType[T](prefix: Manifest[_], clazz: Predef.Class[_], args: Manifest[_]*): Manifest[T] =
new ClassTypeManifest[T](Some(prefix), clazz, args.toList)
@SerialVersionUID(1L)
private abstract class PhantomManifest[T](_runtimeClass: Predef.Class[_],
override val toString: String) extends ClassTypeManifest[T](None, _runtimeClass, Nil) {
override def equals(that: Any): Boolean = this eq that.asInstanceOf[AnyRef]
@transient
override val hashCode = System.identityHashCode(this)
}
/** Manifest for the class type `clazz[args]`, where `clazz` is
* a top-level or static class. */
@SerialVersionUID(1L)
private class ClassTypeManifest[T](prefix: Option[Manifest[_]],
val runtimeClass: Predef.Class[_],
override val typeArguments: List[Manifest[_]]) extends Manifest[T] {
override def toString =
(if (prefix.isEmpty) "" else prefix.get.toString+"#") +
(if (runtimeClass.isArray) "Array" else runtimeClass.getName) +
argString
}
def arrayType[T](arg: Manifest[_]): Manifest[Array[T]] =
arg.asInstanceOf[Manifest[T]].arrayManifest
@SerialVersionUID(1L)
private class AbstractTypeManifest[T](prefix: Manifest[_], name: String, upperBound: Predef.Class[_], args: scala.collection.Seq[Manifest[_]]) extends Manifest[T] {
def runtimeClass = upperBound
override val typeArguments = args.toList
override def toString = prefix.toString+"#"+name+argString
}
/** Manifest for the abstract type `prefix # name`. `upperBound` is not
* strictly necessary as it could be obtained by reflection. It was
* added so that erasure can be calculated without reflection. */
def abstractType[T](prefix: Manifest[_], name: String, upperBound: Predef.Class[_], args: Manifest[_]*): Manifest[T] =
new AbstractTypeManifest[T](prefix, name, upperBound, args)
@SerialVersionUID(1L)
private class WildcardManifest[T](lowerBound: Manifest[_], upperBound: Manifest[_]) extends Manifest[T] {
def runtimeClass = upperBound.runtimeClass
override def toString =
"_" +
(if (lowerBound eq Nothing) "" else " >: "+lowerBound) +
(if (upperBound eq Nothing) "" else " <: "+upperBound)
}
/** Manifest for the unknown type `_ >: L <: U` in an existential.
*/
def wildcardType[T](lowerBound: Manifest[_], upperBound: Manifest[_]): Manifest[T] =
new WildcardManifest[T](lowerBound, upperBound)
@SerialVersionUID(1L)
private class IntersectionTypeManifest[T](parents: Array[Manifest[_]]) extends Manifest[T] {
// We use an `Array` instead of a `Seq` for `parents` to avoid cyclic dependencies during deserialization
// which can cause serialization proxies to leak and cause a ClassCastException.
def runtimeClass = parents(0).runtimeClass
override def toString = parents.mkString(" with ")
}
/** Manifest for the intersection type `parents_0 with ... with parents_n`. */
def intersectionType[T](parents: Manifest[_]*): Manifest[T] =
new IntersectionTypeManifest[T](parents.toArray)
}