Scala example source code file (manifests.scala)

This example Scala source code file (manifests.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

a, array, array, bar, foo, foo, list, list, manifest, t, t, test1, test2, testutil

The Scala manifests.scala source code

object Test extends App {
  Test1
  Test2
  //Test3  // Java 1.5+ only
}

class Foo[T](x: T)
trait Bar[T] { def f: T }

object Test1 extends TestUtil {
  print(())
  print(true)
  print('a')
  print(1)
  print("abc")
  print('abc)
  println()

  print(List(()))
  print(List(true))
  print(List(1))
  print(List("abc"))
  print(List('abc))
  println()

  //print(Array(()))  //Illegal class name "[V" in class file Test$
  print(Array(true))
  print(Array('a'))
  print(Array(1))
  print(Array("abc"))
  print(Array('abc))
  println()

  print(((), ()))
  print((true, false))
  print((1, 2))
  print(("abc", "xyz"))
  print(('abc, 'xyz))
  println()

  // Disabled: should these work? changing the inference for objects from
  // "object Test" to "Test.type" drags in a singleton manifest which for
  // some reason leads to serialization failure.
  // print(Test)
  // print(List)
  println()

  print(new Foo(2))
  print(new Foo(List(2)))
  print(new Foo(new Foo(2)))
  print(new Foo(List(new Foo(2))))
  println()

  print(new Bar[String] { def f = "abc" })
  println()
}

object Test2 {
  import scala.util.Marshal._
  println("()="+load[Unit](dump(())))
  println("true="+load[Boolean](dump(true)))
  println("a="+load[Char](dump('a')))
  println("1="+load[Int](dump(1)))
  println("'abc="+load[Symbol](dump('abc)))
  println()

  println("List(())="+load[List[Unit]](dump(List(()))))
  println("List(true)="+load[List[Boolean]](dump(List(true))))
  println("List('abc)="+load[List[Symbol]](dump(List('abc))))
  println()

  def loadArray[T](x: Array[Byte])(implicit m: reflect.Manifest[Array[T]]) =
    load[Array[T]](x)(m).deepToString
  println("Array()="+loadArray[Int](dump(Array(): Array[Int])))
  println("Array(true)="+loadArray[Boolean](dump(Array(true))))
  println("Array(a)="+loadArray[Char](dump(Array('a'))))
  println("Array(1)="+loadArray[Int](dump(Array(1))))
  println()

  println("((),())="+load[(Unit, Unit)](dump(((), ()))))
  println("(true,false)="+load[(Boolean, Boolean)](dump((true, false))))
  println()

  println("List(List(1), List(2))="+load[List[List[Int]]](dump(List(List(1), List(2)))))
  println()

  println("Array(Array(1), Array(2))="+loadArray[Array[Int]](dump(Array(Array(1), Array(2)))))
  println()
}

object Test3 extends TestUtil {
  import scala.reflect.Manifest._
  val ct1 = classType(classOf[Char])
  val ct2 = classType(classOf[List[_]], ct1)
  print(ct1)
  //print(ct2)  // ??? x=scala.List[char], m=scala.reflect.Manifest[scala.runtime.Nothing$]
  println()
}

trait TestUtil {
  import java.io._
  def write[A](o: A): Array[Byte] = {
    val ba = new ByteArrayOutputStream(512)
    val out = new ObjectOutputStream(ba)
    out.writeObject(o)
    out.close()
    ba.toByteArray()
  }
  def read[A](buffer: Array[Byte]): A = {
    val in = new ObjectInputStream(new ByteArrayInputStream(buffer))
    in.readObject().asInstanceOf[A]
  }
  import scala.reflect._
  def print[T](x: T)(implicit m: Manifest[T]) {
    val m1: Manifest[T] = read(write(m))
    val x1 = x.toString.replaceAll("@[0-9a-z]+$", "")
    println("x="+x1+", m="+m1)
  }
}