diff -r c616ec6b1e3c -r c603b27083f3 Fahad/Scala/Chapter6.sc --- a/Fahad/Scala/Chapter6.sc Wed Jan 21 12:32:17 2015 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,69 +0,0 @@ -package greeter - - -object Chapter6 { - println("Classes and Objects") //> Classes and Objects - - class Rational(n: Int, d: Int) { - private def gcd(x: Int, y: Int): Int = { - if (x == 0) y - else if (x < 0) gcd(-x, y) - else if (y < 0) -gcd(x, -y) - else gcd(y % x, x) - } - private val g = gcd(n, d) - - val numer: Int = n / g - val denom: Int = d / g - def +(that: Rational) = new Rational(numer * that.denom + that.numer * denom, denom * that.denom) - def -(that: Rational) = new Rational(numer * that.denom - that.numer * denom, denom * that.denom) - def *(that: Rational) = new Rational(numer * that.numer, denom * that.denom) - def /(that: Rational) = new Rational(numer * that.denom, denom * that.numer) - - //Inheritance and Overriding - override def toString = "" + numer + "/" + denom - //Parameterless Methods - def square = new Rational(numer * numer, denom * denom) - } - //Inheritance and Overriding - var i = 1 //> i : Int = 1 - var x = new Rational(0, 1) //> x : greeter.Chapter6.Rational = 0/1 - while (i <= 10) { - x += new Rational(1, i) - i += 1 - } - println("" + x.numer + "/" + x.denom) //> 7381/2520 - //Parameterless Methods - val r = new Rational(3, 4) //> r : greeter.Chapter6.Rational = 3/4 - println(r.square) //> 9/16 - - //Abstract Classes - abstract class IntSet { - def incl(x: Int): IntSet - def contains(x: Int): Boolean - } - - //Triats - trait IntSett { - def incl(x: Int): IntSet - def contains(x: Int): Boolean - } - - //Implementing abstract class - class EmptySet extends IntSet { - def contains(x: Int): Boolean = false - def incl(x: Int): IntSet = new NonEmptySet(x, new EmptySet, new EmptySet) - } - - class NonEmptySet(elem: Int, left: IntSet, right: IntSet) extends IntSet { - def contains(x: Int): Boolean = - if (x < elem) left contains x - else if (x > elem) right contains x - else true - def incl(x: Int): IntSet = - if (x < elem) new NonEmptySet(elem, left incl x, right) - else if (x > elem) new NonEmptySet(elem, left, right incl x) - else this - } - -}