Scala example source code file (viewtest.scala)

This example Scala source code file (viewtest.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

app, app, array, array, int, list, list, seq, seqview, seqview, test

The Scala viewtest.scala source code

object Test extends App {
  import collection._
  val xs: SeqView[(String, Int), Seq[_]] = List("x").view.zip(Stream.from(0))
  println(xs)

  val ys = List(1, 2, 3).view map { x => println("mapping "+x); x + 1 }
  println("ys defined")
  println(ys.head)
  println(ys.tail)
  println(ys(2))
  println(ys)
  println(ys.force)

  val zs = Array(1, 2, 3).view
  val as: SeqView[Int, Array[Int]] = zs map (_ + 1)
  val bs: Array[Int] = as.force
  val cs = zs.reverse
  cs(0) += 1
  assert(cs.force.deep == Array(4, 2, 1).deep)
  assert(zs(2) == 4)
  assert(bs.deep == Array(2, 3, 4).deep)
}

/* crash confirmed.
2.8 regression: CCE when zipping list projection with stream
Reported by: 	szeiger 	Owned by: 	odersky
Priority: 	normal 	Component: 	Standard Library
Keywords: 	collections, zip 	Cc: 	
Fixed in version: 	
Description

Welcome to Scala version 2.8.0.r18784-b20090925021043 (Java HotSpot(TM) Client VM, Java 1.6.0_11).
Type in expressions to have them evaluated.
Type :help for more information.

scala> List("x").view.zip(Stream.from(0))List("x").view.zip(Stream.from(0))
java.lang.ClassCastException: scala.collection.generic.IterableViewTemplate$$anon$8 cannot be cast to scala.collection.generic.SequenceView
        at .<init>(:5)
        at .<clinit>()
        at RequestResult$.<init>(:4)
        at RequestResult$.<clinit>()
        at RequestResult$result(<console>)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.Nat...
*/