Scala example source code file (typerep.scala)

This example Scala source code file (typerep.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

a2, a2, a3, a3, a4, a4, a5, a6, a7, a8, b, int, typerep, typerep

The Scala typerep.scala source code

//############################################################################
// Type Representation at runtime
//############################################################################

import TypeRep._

object Test extends App {
  testPrimitives
  testOptions
  testLists
  testArrays
  testTuples
  testFuncs
  testClasses
}

object serialize {
  import java.io._

  @throws(classOf[IOException])
  def write[A](o: A): Array[Byte] = {
    val ba = new ByteArrayOutputStream(512)
    val out = new ObjectOutputStream(ba)
    out.writeObject(o)
    out.close()
    ba.toByteArray()
  }
  @throws(classOf[IOException])
  @throws(classOf[ClassNotFoundException])
  def read[A](buffer: Array[Byte]): A = {
    val in =
      new ObjectInputStream(new ByteArrayInputStream(buffer))
    in.readObject().asInstanceOf[A]
  }
}

object testPrimitives {
  println(getType(true))
  val b = false; val bt = getType(b)
  println(bt)
  val bt1: TypeRep[Boolean] = serialize.read(serialize.write(bt))
  println(bt1 == bt)
  println(getType(16.toByte))
  println(getType('a'))
  println(getType(3))
  println(getType(3l))
  println(getType(0.0f))
  println(getType(0.0d))
  println(getType("abc"))
  println(getType(())) // Unit
  println(getType(classOf[Int])) // Class
  println
}

object testOptions {
  println(getType(Some(2)))
  val x: Option[Int] = Some(2)
  println(getType(x))
  println(getType(Some(Some(3))))
  println(getType(Some(List(3))))
  //println(getType(Some(None: List[Int])))  // error: no implicit argument matching parameter type TypeRep[object None] was foun
  println(getType(None: Option[Int]))
  val y: Option[Int] = None
  println(getType(y))
  println
}

object testLists {
  println(getType(List(3)))
  println(getType(3 :: Nil))
  println(getType(List(List(3))))
  println(getType(Nil: List[Int]))
  println(getType(List(1, "abc")))
  println
}

object testArrays {
  println(getType(Array(3)))
  println(getType(Array(Array(3), Array(4))))
  println(getType(new Array[Int](0)))
  println(getType(List(1).toArray))
  println(getType(List[Int]().toArray))
  println(getType(Array(3).drop(1).toArray)) // empty
  println
}

object testTuples {
  println(getType((3, "abc")))
  println(getType(Triple('a', 'b', "c")))
  println(getType(((3, "abc"), (4, "xyz"))))
  println(getType(((Some('b'), 3), (Some('a'), 4))))
  //println(getType(((Some('b'), 3), (None, 4))))
  println
}

object testFuncs {
  def f1(x: Int): Int = 2 * x
  println(getType(f1 _))
  println(getType(f1(2)))
  val f2 = (x: Int) => 2 * x
  println(getType(f2))
  println(getType(f2(2)))
  val f3 = (x: Int) => (y: Int) => x + y
  println(getType(f3))
  println(getType(f3(2)))
  println(getType(f3(2)(2)))
  def f4(b: Boolean, c: List[Char], i: Int): Int = i
  println(getType(f4 _))
  def f5(f: Int => Int, x: Int) = f(x)
  println(getType(f5 _))
  println(getType(f5(f1, 1)))
  println  
}

class Foo {
  class Bar(x: Int)
}


object foo extends Foo

package pkg1 {
  class C1
  object c1 extends C1
}

object testClasses {
  /*
  case object FooRep extends TypeRep[Foo] {
    override def toString = "Foo"
  }
  implicit def fooRep[A](x: A)(implicit rep: TypeRep[foo.type]): TypeRep[foo.type] = rep
  println(getType(foo))
  println(getType(new foo.Bar(0)))
  val foo2 = new Foo
  println(getType(foo2))
  println(getType(new foo2.Bar(1)))
  println

  println(getType(pkg1.c1))
  val c1 = new pkg1.C1
  println(getType(c1))
  println
  */
}


/**
 *  @author Stephane Micheloud
 *  @version 1.0
 */
abstract class TypeRep[A]

object TypeRep {

  def getType[A](x: A)(implicit rep: TypeRep[A]): TypeRep[A] = rep

  def getType[A](x: Option[A])(implicit rep: TypeRep[A]): TypeRep[Option[A]] = (x match {
    case Some(v) => SomeRep(rep)
    case None    => NoneRep
  }).asInstanceOf[TypeRep[Option[A]]]

  def getType[A](x: List[A])(implicit rep: TypeRep[A]): TypeRep[List[A]] = (x match {
    case h :: t => ListRep(getType(h))
    case Nil    => NilRep
  }).asInstanceOf[TypeRep[List[A]]]

  implicit def boolRep: TypeRep[Boolean] = BooleanRep
  implicit def byteRep: TypeRep[Byte] = ByteRep
  implicit def charRep: TypeRep[Char] = CharRep
  implicit def shortRep: TypeRep[Short] = ShortRep
  implicit def intRep: TypeRep[Int] = IntRep
  implicit def longRep: TypeRep[Long] = LongRep
  implicit def floatRep: TypeRep[Float] = FloatRep
  implicit def doubleRep: TypeRep[Double] = DoubleRep

  implicit def unitRep: TypeRep[Unit] = UnitRep
  implicit def stringRep: TypeRep[String] = StringRep
  //implicit def noneRep: TypeRep[None.type] = NoneRep//[Nothing](NothingRep.asInstanceOf[TypeRep[Nothing]])
  implicit def anyRep: TypeRep[Any] = AnyRep
  implicit def nothingRep: TypeRep[Nothing] = NothingRep

  implicit def classRep[A](implicit elemrep: TypeRep[A]): TypeRep[Class[A]] =
    ClassRep(elemrep)

  implicit def someRep[A](implicit elemrep: TypeRep[A]): TypeRep[Some[A]] =
    SomeRep(elemrep)

  implicit def listRep[A](implicit elemrep: TypeRep[A]): TypeRep[List[A]] =
    ListRep(elemrep)

  implicit def arrayRep[A](implicit elemrep: TypeRep[A]): TypeRep[Array[A]] =
    ArrayRep(elemrep)

  implicit def tuple2Rep[A1, A2](implicit _1: TypeRep[A1], _2: TypeRep[A2]): TypeRep[(A1, A2)] =
    Tuple2Rep(_1, _2)

  implicit def tuple3Rep[A1, A2, A3](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3]): TypeRep[(A1, A2, A3)] =
    Tuple3Rep(_1, _2, _3)
  implicit def tuple4Rep[A1, A2, A3, A4](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4]): TypeRep[Tuple4[A1, A2, A3, A4]] =
    Tuple4Rep(_1, _2, _3, _4)
  implicit def tuple5Rep[A1, A2, A3, A4, A5](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4], _5: TypeRep[A5]): TypeRep[Tuple5[A1, A2, A3, A4, A5]] =
    Tuple5Rep(_1, _2, _3, _4, _5)
  implicit def tuple6Rep[A1, A2, A3, A4, A5, A6](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4], _5: TypeRep[A5], _6: TypeRep[A6]): TypeRep[Tuple6[A1, A2, A3, A4, A5, A6]] =
    Tuple6Rep(_1, _2, _3, _4, _5, _6)
  implicit def tuple7Rep[A1, A2, A3, A4, A5, A6, A7](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4], _5: TypeRep[A5], _6: TypeRep[A6], _7: TypeRep[A7]): TypeRep[Tuple7[A1, A2, A3, A4, A5, A6, A7]] =
    Tuple7Rep(_1, _2, _3, _4, _5, _6, _7)
  implicit def tuple8Rep[A1, A2, A3, A4, A5, A6, A7, A8](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4], _5: TypeRep[A5], _6: TypeRep[A6], _7: TypeRep[A7], _8: TypeRep[A8]): TypeRep[Tuple8[A1, A2, A3, A4, A5, A6, A7, A8]] =
    Tuple8Rep(_1, _2, _3, _4, _5, _6, _7, _8)
  implicit def tuple9Rep[A1, A2, A3, A4, A5, A6, A7, A8, A9](implicit _1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4], _5: TypeRep[A5], _6: TypeRep[A6], _7: TypeRep[A7], _8: TypeRep[A8], _9: TypeRep[A9]): TypeRep[Tuple9[A1, A2, A3, A4, A5, A6, A7, A8, A9]] =
    Tuple9Rep(_1, _2, _3, _4, _5, _6, _7, _8, _9)

  implicit def func1Rep[A1, B](implicit a1: TypeRep[A1], b: TypeRep[B]): TypeRep[Function1[A1, B]] =
    Function1Rep(a1, b)
  implicit def func2Rep[A1, A2, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], b: TypeRep[B]): TypeRep[Function2[A1, A2, B]] =
    Function2Rep(a1, a2, b)
  implicit def func3Rep[A1, A2, A3, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], b: TypeRep[B]): TypeRep[Function3[A1, A2, A3, B]] =
    Function3Rep(a1, a2, a3, b)
  implicit def func4Rep[A1, A2, A3, A4, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], b: TypeRep[B]): TypeRep[Function4[A1, A2, A3, A4, B]] =
    Function4Rep(a1, a2, a3, a4, b)
  implicit def func5Rep[A1, A2, A3, A4, A5, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], b: TypeRep[B]): TypeRep[Function5[A1, A2, A3, A4, A5, B]] =
    Function5Rep(a1, a2, a3, a4, a5, b)
  implicit def func6Rep[A1, A2, A3, A4, A5, A6, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], b: TypeRep[B]): TypeRep[Function6[A1, A2, A3, A4, A5, A6, B]] =
    Function6Rep(a1, a2, a3, a4, a5, a6, b)
  implicit def func7Rep[A1, A2, A3, A4, A5, A6, A7, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], a7: TypeRep[A7], b: TypeRep[B]): TypeRep[Function7[A1, A2, A3, A4, A5, A6, A7, B]] =
    Function7Rep(a1, a2, a3, a4, a5, a6, a7, b)
  implicit def func8Rep[A1, A2, A3, A4, A5, A6, A7, A8, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], a7: TypeRep[A7], a8: TypeRep[A8], b: TypeRep[B]): TypeRep[Function8[A1, A2, A3, A4, A5, A6, A7, A8, B]] =
    Function8Rep(a1, a2, a3, a4, a5, a6, a7, a8, b)
  implicit def func9Rep[A1, A2, A3, A4, A5, A6, A7, A8, A9, B](implicit a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], a7: TypeRep[A7], a8: TypeRep[A8], a9: TypeRep[A9], b: TypeRep[B]): TypeRep[Function9[A1, A2, A3, A4, A5, A6, A7, A8, A9, B]] =
    Function9Rep(a1, a2, a3, a4, a5, a6, a7, a8, a9, b)
/*
  implicit def objectRep[A <: AnyRef](obj: A)(implicit rep: TypeRep[A]): TypeRep[AnyClass] =
    ObjectRep(obj.getClass)
*/

  case object BooleanRep extends TypeRep[Boolean] {
    override def toString = "Boolean"
  }
  case object ByteRep extends TypeRep[Byte] {
    override def toString = "Byte"
  }
  case object CharRep extends TypeRep[Char] {
    override def toString = "Char"
  }
  case object ShortRep extends TypeRep[Short] {
    override def toString = "Short"
  }
  case object IntRep extends TypeRep[Int] {
    override def toString = "Int"
  }
  case object LongRep extends TypeRep[Long] {
    override def toString = "Long"
  }
  case object FloatRep extends TypeRep[Float] {
    override def toString = "Float"
  }
  case object DoubleRep extends TypeRep[Double] {
    override def toString = "Double"
  }

  case object UnitRep extends TypeRep[Unit] {
    override def toString = "Unit"
  }
//  case object ClassRep extends TypeRep[AnyClass] {
//    override def toString = "Class"
//  }
  case object StringRep extends TypeRep[String] {
    override def toString = "String"
  }
  case object NoneRep extends TypeRep[None.type] {
    override def toString = "None"
  }
  case object NilRep extends TypeRep[Nil.type] {
    override def toString = "Nil"
  }
  case object AnyRep extends TypeRep[Any] {
    override def toString = "Any"
  }
  case object NothingRep extends TypeRep[Nothing] {
    override def toString = "Nothing"
  }

  @serializable
  case class ClassRep[A](elemRep: TypeRep[A]) extends TypeRep[Class[A]] {
    override def toString = "Class[" + elemRep + "]"
  }
  @serializable
  case class SomeRep[A](elemRep: TypeRep[A]) extends TypeRep[Some[A]] {
    override def toString = "Some[" + elemRep + "]"
  }
  @serializable
  case class NoneRep[A](elemRep: TypeRep[A]) extends TypeRep[Option[A]] {
    override def toString = "None[" + elemRep + "]"
  }

  @serializable
  case class ListRep[A](elemRep: TypeRep[A]) extends TypeRep[List[A]] {
    override def toString = "List[" + elemRep + "]"
  }

  @serializable
  case class ArrayRep[A](elemRep: TypeRep[A]) extends TypeRep[Array[A]] {
    override def toString = "Array[" + elemRep + "]"
  }

  @serializable
  case class Tuple2Rep[A1, A2](_1: TypeRep[A1], _2: TypeRep[A2]) extends TypeRep[(A1, A2)] {
    override def toString = "Tuple2[" + _1 + ", " + _2 + "]"
  }
  @serializable
  case class Tuple3Rep[A1, A2, A3](_1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3]) extends TypeRep[Tuple3[A1, A2, A3]] {
    override def toString = "Tuple3[" + _1 + ", " + _2 + ", " + _3 + "]"
  }
  @serializable
  case class Tuple4Rep[A1, A2, A3, A4](_1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4]) extends TypeRep[Tuple4[A1, A2, A3, A4]] {
    override def toString = "Tuple4[" + _1 + ", " + _2 + ", " + _3 + ", " + _4 + "]"
  }
  @serializable
  case class Tuple5Rep[A1, A2, A3, A4, A5](_1: TypeRep[A1], _2: TypeRep[A2], _3: TypeRep[A3], _4: TypeRep[A4], _5: TypeRep[A5]) extends TypeRep[Tuple5[A1, A2, A3, A4, A5]] {
    override def toString = "Tuple5[" + _1 + ", " + _2 + ", " + _3 + ", " + _4 + ", " + _5 + "]"
  }
  @serializable
  case class Tuple6Rep[A1, A2, A3, A4, A5, A6](val _1: TypeRep[A1], val _2: TypeRep[A2], val _3: TypeRep[A3], val _4: TypeRep[A4], val _5: TypeRep[A5], val _6: TypeRep[A6]) extends TypeRep[Tuple6[A1, A2, A3, A4, A5, A6]] {
    override def toString = "Tuple6[" + _1 + ", " + _2 + ", " + _3 + ", " + _4 + ", " + _5 + ", " + _6 + "]"
  }
  @serializable
  case class Tuple7Rep[A1, A2, A3, A4, A5, A6, A7](val _1: TypeRep[A1], val _2: TypeRep[A2], val _3: TypeRep[A3], val _4: TypeRep[A4], val _5: TypeRep[A5], val _6: TypeRep[A6], val _7: TypeRep[A7]) extends TypeRep[Tuple7[A1, A2, A3, A4, A5, A6, A7]] {
    override def toString = "Tuple7[" + _1 + ", " + _2 + ", " + _3 + ", " + _4 + ", " + _5 + ", " + _6 + ", " + _7 + "]"
  }
  @serializable
  case class Tuple8Rep[A1, A2, A3, A4, A5, A6, A7, A8](val _1: TypeRep[A1], val _2: TypeRep[A2], val _3: TypeRep[A3], val _4: TypeRep[A4], val _5: TypeRep[A5], val _6: TypeRep[A6], val _7: TypeRep[A7], val _8: TypeRep[A8]) extends TypeRep[Tuple8[A1, A2, A3, A4, A5, A6, A7, A8]] {
    override def toString = "Tuple8[" + _1 + ", " + _2 + ", " + _3 + ", " + _4 + ", " + _5 + ", " + _6 + ", " + _7 + ", " + _8 + "]"
  }
  @serializable
  case class Tuple9Rep[A1, A2, A3, A4, A5, A6, A7, A8, A9](val _1: TypeRep[A1], val _2: TypeRep[A2], val _3: TypeRep[A3], val _4: TypeRep[A4], val _5: TypeRep[A5], val _6: TypeRep[A6], val _7: TypeRep[A7], val _8: TypeRep[A8], val _9: TypeRep[A9]) extends TypeRep[Tuple9[A1, A2, A3, A4, A5, A6, A7, A8, A9]] {
    override def toString = "Tuple9[" + _1 + ", " + _2 + ", " + _3 + ", " + _4 + ", " + _5 + ", " + _6 + ", " + _7 + ", " + _8 + ", " + _9 + "]"
  }

  @serializable
  case class Function1Rep[A1, B](a1: TypeRep[A1], b: TypeRep[B]) extends TypeRep[Function1[A1, B]] {
    override def toString = "Function1[" + a1 + ", " + b + "]"
  }
  @serializable
  case class Function2Rep[A1, A2, B](a1: TypeRep[A1], a2: TypeRep[A2], b: TypeRep[B]) extends TypeRep[Function2[A1, A2, B]] {
    override def toString = "Function2[" + a1 + ", " + a2 + ", " + b + "]"
  }
  @serializable
  case class Function3Rep[A1, A2, A3, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], b: TypeRep[B]) extends TypeRep[Function3[A1, A2, A3, B]] {
    override def toString = "Function3[" + a1 + ", " + a2 + ", " + a3 + ", " + b + "]"
  }
  @serializable
  case class Function4Rep[A1, A2, A3, A4, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], b: TypeRep[B]) extends TypeRep[Function4[A1, A2, A3, A4, B]] {
    override def toString = "Function4[" + a1 + ", " + a2 + ", " + a3 + ", " + a4 + ", " + b + "]"
  }
  @serializable
  case class Function5Rep[A1, A2, A3, A4, A5, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], b: TypeRep[B]) extends TypeRep[Function5[A1, A2, A3, A4, A5, B]] {
    override def toString = "Function5[" + a1 + ", " + a2 + ", " + a3 + ", " + a4 + ", " + a5 + ", " + b + "]"
  }
  @serializable
  case class Function6Rep[A1, A2, A3, A4, A5, A6, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], b: TypeRep[B]) extends TypeRep[Function6[A1, A2, A3, A4, A5, A6, B]] {
    override def toString = "Function6[" + a1 + ", " + a2 + ", " + a3 + ", " + a4 + ", " + a5 + ", " + a6 + ", " + b + "]"
  }
  @serializable
  case class Function7Rep[A1, A2, A3, A4, A5, A6, A7, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], a7: TypeRep[A7], b: TypeRep[B]) extends TypeRep[Function7[A1, A2, A3, A4, A5, A6, A7, B]] {
    override def toString = "Function7[" + a1 + ", " + a2 + ", " + a3 + ", " + a4 + ", " + a5 + ", " + a6 + ", " + a7 + ", " + b + "]"
  }
  @serializable
  case class Function8Rep[A1, A2, A3, A4, A5, A6, A7, A8, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], a7: TypeRep[A7], a8: TypeRep[A8], b: TypeRep[B]) extends TypeRep[Function8[A1, A2, A3, A4, A5, A6, A7, A8, B]] {
    override def toString = "Function8[" + a1 + ", " + a2 + ", " + a3 + ", " + a4 + ", " + a5 + ", " + a6 + ", " + a7 + ", " + a8 + b + "]"
  }
  @serializable
  case class Function9Rep[A1, A2, A3, A4, A5, A6, A7, A8, A9, B](a1: TypeRep[A1], a2: TypeRep[A2], a3: TypeRep[A3], a4: TypeRep[A4], a5: TypeRep[A5], a6: TypeRep[A6], a7: TypeRep[A7], a8: TypeRep[A8], a9: TypeRep[A9], b: TypeRep[B]) extends TypeRep[Function9[A1, A2, A3, A4, A5, A6, A7, A8, A9, B]] {
    override def toString = "Function9[" + a1 + ", " + a2 + ", " + a3 + ", " + a4 + ", " + a5 + ", " + a6 + ", " + a7 + ", " + a8 + ", " + b + "]"
  }
/*
  @serializable
  case class ObjectRep[A](c: Class) extends TypeRep[A] {
    override def toString = c.getName
  }
*/
}