Scala example source code file (SymbolsTest.scala)

This example Scala source code file (SymbolsTest.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

anyref, anyref, base, compl, inner, lazy2, list, signs, signs, sub, sub, symbol, symbol, val

The Scala SymbolsTest.scala source code

class Slazz {
  val s1 = 'myFirstSymbol
  val s2 = 'mySecondSymbol
  def s3 = 'myThirdSymbol
  var s4: Symbol = null

  s4 = 'myFourthSymbol
}

class Base {
  val basesymbol = 'symbase
}

class Sub extends Base {
  val subsymbol = 'symsub
}

trait Signs {
  val ind = 'indication
  val trace = 'trace
}

trait Lazy1 {
  lazy val v1 = "lazy v1"
  lazy val s1 = 'lazySymbol1
}

trait Lazy2 {
  lazy val v2 = "lazy v2"
  lazy val s2 = 'lazySymbol2
}

trait Lazy3 {
  lazy val v3 = "lazy v3"
  lazy val s3 = 'lazySymbol3
}

object SingletonOfLazyness {
  lazy val lazysym = 'lazySymbol
  lazy val another = 'another
  lazy val lastone = 'lastone
}

/*
 * Tests symbols to see if they work correct.
 */
object Test {
  class Inner {
    val simba = 'smba
    var mfs: Symbol = null
    mfs = Symbol("mfsa")
  }
  
  object InnerObject {
    val o1 = 'aaa
    val o2 = 'ddd
  }

  def aSymbol = 'myFirstSymbol
  val anotherSymbol = 'mySecondSymbol

  def main(args: Array[String]) {
    testLiterals
    testForLoop
    testInnerClasses
    testInnerObjects
    testWithHashMaps
    testLists
    testAnonymous
    testNestedObject
    testInheritance
    testTraits
    testLazyTraits
    testLazyObjects
  }

  def testLiterals {
    val scl = new Slazz
    assert(scl.s1 == aSymbol)
    assert(scl.s2 == anotherSymbol)
    assert(scl.s3 == 'myThirdSymbol)
    assert(scl.s4 == Symbol.apply("myFourthSymbol"))
    assert(scl.s1 == Symbol("myFirstSymbol"))
  }

  def testForLoop {
    for (i <- 0 until 100) List("Val" + i)
  }

  def testInnerClasses {
    val innerPower = new Inner
    assert(innerPower.simba == 'smba)
    assert(innerPower.mfs == 'mfsa)
  }

  def testInnerObjects {
    assert(InnerObject.o1 == 'aaa)
    assert(InnerObject.o2 == 'ddd)
  }
  
  def testWithHashMaps {
    val map = new collection.mutable.HashMap[Symbol, Symbol]
    map.put(InnerObject.o1, 'smba)
    map.put(InnerObject.o2, 'mfsa)
    map.put(Symbol("WeirdKey" + 1), Symbol("Weird" + "Val" + 1))
    assert(map('aaa) == 'smba)
    assert(map('ddd) == 'mfsa)
    assert(map('WeirdKey1) == Symbol("WeirdVal1"))
    
    map.clear
    for (i <- 0 until 100) map.put(Symbol("symKey" + i), Symbol("symVal" + i))
    assert(map(Symbol("symKey15")) == Symbol("symVal15"))
    assert(map('symKey22) == 'symVal22)
    assert(map('symKey73) == 'symVal73)
    assert(map('symKey56) == 'symVal56)
    assert(map('symKey91) == 'symVal91)
  }

  def testLists {
    var lst: List[Symbol] = Nil
    for (i <- 0 until 100) lst ::= Symbol("lsym" + (99 - i))
    assert(lst(0) == 'lsym0)
    assert(lst(10) == 'lsym10)
    assert(lst(30) == 'lsym30)
    assert(lst(40) == 'lsym40)
    assert(lst(65) == 'lsym65)
    assert(lst(90) == 'lsym90)
  }

  def testAnonymous { // TODO complaints classdef can't be found for some reason, runs fine in my case
    // val anon = () => {
    //   val simba = 'smba
    //   simba
    // }
    // val an2 = () => {
    //   object nested {
    // 	val m = 'mfsa
    //   }
    //   nested.m
    // }
    // val an3 = () => {
    //   object nested {
    // 	val f = () => {
    // 	  'layered
    // 	}
    // 	def gets = f()
    //   }
    //   nested.gets
    // }
    // val inner = new Inner
    // assert(anon() == inner.simba)
    // assert(anon().toString == "'smba")
    // assert(an2() == 'mfsa)
    // assert(an3() == Symbol("layered" + ""))
  }

  def testNestedObject {
    object nested {
      def sign = 'sign
      def insignia = 'insignia
    }
    assert(nested.sign == 'sign)
    assert(nested.insignia == 'insignia)
    assert(('insignia).toString == "'insignia")
  }

  def testInheritance {
    val base = new Base
    val sub = new Sub
    assert(base.basesymbol == 'symbase)
    assert(sub.subsymbol == 'symsub)
    assert(sub.basesymbol == 'symbase)

    val anon = new Sub {
      def subsubsymbol = 'symsubsub
    }
    assert(anon.subsubsymbol == 'symsubsub)
    assert(anon.subsymbol == 'symsub)
    assert(anon.basesymbol == 'symbase)
    
    object nested extends Sub {
      def objsymbol = 'symobj
    }
    assert(nested.objsymbol == 'symobj)
    assert(nested.subsymbol == 'symsub)
    assert(nested.basesymbol == 'symbase)
    assert(('symbase).toString == "'symbase")
  }

  def testTraits {
    val fromTrait = new AnyRef with Signs {
      def traitsymbol = 'traitSymbol
    }

    assert(fromTrait.traitsymbol == 'traitSymbol)
    assert(fromTrait.ind == 'indication)
    assert(fromTrait.trace == 'trace)
    assert(('trace).toString == "'trace")

    trait Compl {
      val s1 = 's1
      def s2 = 's2
      object inner {
	val s3 = 's3
	val s4 = 's4
      }
    }

    val compl = new Sub with Signs with Compl
    assert(compl.s1 == 's1)
    assert(compl.s2 == 's2)
    assert(compl.inner.s3 == 's3)
    assert(compl.inner.s4 == 's4)
    assert(compl.ind == 'indication)
    assert(compl.trace == 'trace)
    assert(compl.subsymbol == 'symsub)
    assert(compl.basesymbol == 'symbase)

    object Local extends Signs with Compl {
      val s5 = 's5
      def s6 = 's6
      object inner2 {
	val s7 = 's7
	def s8 = 's8
      }
    }
    assert(Local.s5 == 's5)
    assert(Local.s6 == 's6)
    assert(Local.inner2.s7 == 's7)
    assert(Local.inner2.s8 == 's8)
    assert(Local.inner.s3 == 's3)
    assert(Local.inner.s4 == 's4)
    assert(Local.s1 == 's1)
    assert(Local.s2 == 's2)
    assert(Local.trace == 'trace)
    assert(Local.ind == 'indication)
    assert(('s8).toString == "'s8")
  }

  def testLazyTraits {
    val l1 = new AnyRef with Lazy1
    val l2 = new AnyRef with Lazy2
    val l3 = new AnyRef with Lazy3

    l1.v1
    l2.v2
    l3.v3
    assert((l1.s1).toString == "'lazySymbol1")
    assert(l2.s2 == Symbol("lazySymbol" + 2))
    assert(l3.s3 == 'lazySymbol3)
  }

  def testLazyObjects {
    assert(SingletonOfLazyness.lazysym == 'lazySymbol)
    assert(SingletonOfLazyness.another == Symbol("ano" + "ther"))
    assert((SingletonOfLazyness.lastone).toString == "'lastone")

    object nested {
      lazy val sym1 = 'snested1
      lazy val sym2 = 'snested2
    }

    assert(nested.sym1 == 'snested1)
    assert(nested.sym2 == Symbol("snested" + "2"))
  }

}