Scala example source code file (structural.scala)

This example Scala source code file (structural.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, anyref, array, array, exc, int, object, object, string, t, t, tata, tata, unit

The Scala structural.scala source code

object test1 {
  
  val o1 = new Object { override def toString = "ohone" }
  val o2 = new Object { override def toString = "ohtwo" }
  
  val t1 = new Tata("tieone")
  val t2 = new Tata("tietwo")
  
  class Tata(name: String) {
    override def toString = name
    def tatMe = "oy"
  }
  
  class Titi extends Tata("titi")
  
  object Rec {
    val a = 1
    val b = 2
    val c = "hey"
    def d(x: AnyRef) = new Object { override def toString = "dee" }
    def e(x: Tata) = new Tata("iei")
    def f(x: Int) = x + 1
    def g(x: Int) = { v = x }
    def h(x: Unit) = new Object { override def toString = "eitch" }
    def i(x: Array[Int]) = x(0)
    def j(x: Array[AnyRef]) = x(0)
    def k(x: Array[Char]) = x(0)
    def l(x: Array[Unit]) = x(0)
    def m(x: Array[String]) = x(0)
    def n(x: Array[Tata]) = x(0)
    def o: Array[Int] = Array(1, 2, 3)
    def p: Array[AnyRef] = Array(o1, o2)
    def q: Array[Char] = Array('1', '2')
    def r: Array[Unit] = Array((), ())
    def s: Array[String] = Array("one", "two")
    def t: Array[Tata] = Array(t1, t2)
    def u[T](f: T=>T, v:T): T = f(v)
    var v = 4
    var w = 11
    val x = t1
    val y: Tata = null
    def z(t: Tata) = ()
  }
  
  type rt = Object {
    val a: Int;
    val c: String;
    def d(x: AnyRef): AnyRef
    def e(x: Tata): Tata
    def f(x: Int): Int;
    def h(x: Unit): AnyRef;
    def i(x: Array[Int]): Int
    def j(x: Array[AnyRef]): AnyRef
    def k(x: Array[Char]): Char
    def l(x: Array[Unit]): Unit
    def m(x: Array[String]): String
    def n(x: Array[Tata]): Tata
    def o: Array[Int]
    def p: Array[AnyRef]
    def q: Array[Char]
    def r: Array[Unit]
    def s: Array[String]
    def t: Array[Tata]
    def u[T](f: T=>T, v:T): T
    var v: Int
    val y: Tata
  }
  
  def l (r: rt) {
    println(" 1. " + r.c)
    println(" 2. " + r.a + 1)
    println(" 3. " + r.d(o1))
    println(" 4. " + r.e(t1))
    println(" 5. " + (r.f(4) + 1))
    println(" 6. " + r.f(4) + 1)
    println(" 7. " + r.f(r.a))
    println(" 8. " + r.v)
    r.v = r.v + 1
    println("10. " + r.v)
    println("11. " + r.h(()))
    println("12. " + r.i(Array(1, 2, 3)))
    println("13. " + r.j(Array(o1, o2)))
    println("14. " + r.k(Array('1', '2')))
    println("15. " + r.l(Array((), ())))
    println("16. " + r.m(Array("one", "two")))
    println("17. " + r.n(Array(t1, t2)))
    println("18. " + (r.o(0) + 1))
    println("19. " + (r.p(0).hashCode() > 0))
    println("20. " + r.q(0))
    println("21. " + r.r(0))
    println("22. " + r.m(r.s))
    println("23. " + r.t(0).tatMe)
    println("24. " + r.u[Int](_+1,0))
    println("25. " + r.y)
    println("26. " + r.e(null))
  }
  
  /*def ma[T](r: Object{def e(x: T): T; val x: T}) {
    println("30. " + r.e(r.x)) // static error
  }*/
  
  def mb(r: Object { def e[T](x: T): T }) {
    println("31. " + r.e[Int](4)) // while this is ok
  }
  
  def m1(r: Object { def z(x: Tata): Unit }) {
    println("32. " + r.z(new Titi)) // while this is ok
  }
  
  def m2[T](r: Object { def e(x: Tata): T; val x: Tata }) {
    println("33. " + r.e(r.x)) // and this too
  }
  
  class Rec3[T] {
    def e(x: T): T = x
  }
  
  def m3[T](r: Rec3[T], x: T) {
    println("33. " + r.e(x)) // and this too
  }
  
  Rec.g(11)
  
  this.l(Rec)
  this.mb(new Object{def e[T](x: T): T = x})
  this.m1(Rec)
  this.m2[Tata](Rec)
  this.m3[Tata](new Rec3[Tata], t1)
}

object test2 {
  class C extends { def f() { println("1") } }
  val x1 = new C
  x1.f()
  
  abstract class D extends { def f() }
  val x2 = new D { def f() { println("2") } }
  x2.f()

  val x3 = new { def f() { println("3") } }
  def run(x: { def f() }) { x.f() }
  run(x3)

  type T = { def f() }
  val x4 = new AnyRef { def f() { println("4") } } // ok!
  //val x4 = new T { def f() { println("4") } }        // error! (bug #1241)
  x4.f()

  val x5: T = new { def f() { println("5") } }
  x5.f()
}

object test3 {

  case class Exc extends Exception
  
  object Rec {
    def f = throw Exc()
  }
  
  def m(r: { def f: Nothing }) =
    try {
      r.f
    }
    catch {
      case e: Exc => println("caught")
      case e => println(e)
    }
  
  m(Rec)
  
}

object test4 {

  class A
  
  val aar = Array(new A, new A, new A)
  val nar = Array(1, 2)
  
  def f(p: {def size: Int}) = println(p.size)
  //def g[T <: {def size: Int}](p: T) = println(p.size) // open issue
  //def h[T <% {def size: Int}](p: T) = println(p.size) // open issue
  
  f(aar)
  f(nar)
  
  //g(aar)
  //g(nar)
  
  //h(aar)
  //h(nar)
  
}

object Test extends App {
  test1
  test2
  test3
  test4
}