Scala example source code file (range.scala)

This example Scala source code file (range.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

array, gr, gr, illegalargumentexception, integral, list, list, numericrange, numericrange, range, t, test, test, unit

The Scala range.scala source code

import scala.collection.immutable.{ Range, NumericRange }

object Test {
  def rangeForeach(range : Range) = {
    val buffer = new scala.collection.mutable.ListBuffer[Int];
    range.foreach(buffer += _);
    assert(buffer.toList == range.iterator.toList, buffer.toList+"/"+range.iterator.toList)
  }
  
  def boundaryTests() = {
    // #4321
    assert((Int.MinValue to Int.MaxValue by Int.MaxValue).size == 3)
    // #4308
    val caught = (
      try   { (Long.MinValue to Long.MaxValue).sum ; false }
      catch { case _: IllegalArgumentException => true }
    )
    assert(caught)
  }
  
  case class GR[T](val x: T)(implicit val num: Integral[T]) {
    import num._
    
    def negated = GR[T](-x)
    
    def gr1 = NumericRange(x, x, x)
    def gr2 = NumericRange.inclusive(x, x, x)
    def gr3 = NumericRange(x, x * fromInt(10), x)
    def gr4 = NumericRange.inclusive(x, x * fromInt(10), x)
    def gr5 = gr3.toList ::: negated.gr3.toList
    
    def check = {
      assert(gr1.isEmpty && !gr2.isEmpty)
      assert(gr3.size == 9 && gr4.size == 10)      
      assert(gr5.sum == num.zero, gr5.toString)
      assert(!(gr3 contains (x * fromInt(10))))
      assert((gr4 contains (x * fromInt(10))))
    }
  }
  
  def main(args: Array[String]): Unit = {
    implicit val imp1 = Numeric.BigDecimalAsIfIntegral
    implicit val imp2 = Numeric.DoubleAsIfIntegral
    
    val _grs = List[GR[_]](
      GR(BigDecimal(5.0)),
      GR(BigInt(5)),
      GR(5L),
      GR(5.0d),
      GR(2.toByte)
    )
    val grs = _grs ::: (_grs map (_.negated))
    grs foreach (_.check)
    
    assert(NumericRange(1, 10, 1) sameElements (1 until 10))
    assert(NumericRange.inclusive(1, 10, 1) sameElements (1 to 10))
    assert(NumericRange.inclusive(1, 100, 3) sameElements (1 to 100 by 3))
    
    // #2518
    assert((3L to 7 by 2) sameElements List(3L, 5L, 7L))
    
    rangeForeach(1 to 10);
    rangeForeach(1 until 10);
    rangeForeach(10 to 1 by -1);
    rangeForeach(10 until 1 by -1);
    rangeForeach(10 to 1 by -3);
    rangeForeach(10 until 1 by -3);
    
    // living on the edges
    boundaryTests()
  }
}