/*
 * Copyright (C) 2007-2016 Artima, Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Automatically generated Scala interpreter transcript from:
 *
 * Programming in Scala (Third Edition)
 * by Martin Odersky, Lex Spoon, Bill Venners
 *
 * http://booksites.artima.com/programming_in_scala_3ed
 */


scala>   class Rational(n: Int, d: Int) {
           println("Created " + n + "/" + d)
         }

defined class Rational

scala> new Rational(1, 2)
Created 1/2
res0: Rational = Rational@1d7d4a63

scala>   class Rational(n: Int, d: Int) {
           override def toString = n + "/" + d
         }

defined class Rational

scala> val x = new Rational(1, 3)
x: Rational = 1/3

scala> val y = new Rational(5, 7)
y: Rational = 5/7

scala> new Rational(5, 0)
res1: Rational = 5/0

scala>   class Rational(n: Int, d: Int) {
           require(d != 0)
           val numer: Int = n
           val denom: Int = d
           override def toString = numer + "/" + denom
           def add(that: Rational): Rational =
             new Rational(
               numer * that.denom + that.numer * denom,
               denom * that.denom
             )
         }

defined class Rational

scala> val oneHalf = new Rational(1, 2)
oneHalf: Rational = 1/2

scala> val twoThirds = new Rational(2, 3)
twoThirds: Rational = 2/3

scala> oneHalf add twoThirds
res2: Rational = 7/6

scala> val r = new Rational(1, 2)
r: Rational = 1/2

scala> r.numer
res3: Int = 1

scala> r.denom
res4: Int = 2

scala> val y = new Rational(3)
y: Rational = 3/1

scala> new Rational(66, 42)
res5: Rational = 66/42

scala>   class Rational(n: Int, d: Int) {
       
           require(d != 0)
       
           private val g = gcd(n.abs, d.abs)
           val numer = n / g
           val denom = d / g
       
           def this(n: Int) = this(n, 1)
       
           def add(that: Rational): Rational =
             new Rational(
               numer * that.denom + that.numer * denom,
               denom * that.denom
             )
       
           override def toString = numer + "/" + denom
       
           private def gcd(a: Int, b: Int): Int = 
             if (b == 0) a else gcd(b, a % b)
         }

defined class Rational

scala> new Rational(66, 42)
res6: Rational = 11/7

scala>   class Rational(n: Int, d: Int) {
       
           require(d != 0)
       
           private val g = gcd(n.abs, d.abs)
           val numer = n / g
           val denom = d / g
       
           def this(n: Int) = this(n, 1)
       
           def + (that: Rational): Rational =
             new Rational(
               numer * that.denom + that.numer * denom,
               denom * that.denom
             )
       
           def * (that: Rational): Rational =
             new Rational(numer * that.numer, denom * that.denom)
       
           override def toString = numer + "/" + denom
       
           private def gcd(a: Int, b: Int): Int = 
             if (b == 0) a else gcd(b, a % b)
         }

defined class Rational

scala> val x = new Rational(1, 2)
x: Rational = 1/2

scala> val y = new Rational(2, 3)
y: Rational = 2/3

scala> x + y
res7: Rational = 7/6

scala> x.+(y)
res8: Rational = 7/6

scala> x + x * y
res9: Rational = 5/6

scala> (x + x) * y
res10: Rational = 2/3

scala> x + (x * y)
res11: Rational = 5/6

scala>   class Rational(n: Int, d: Int) {
       

            require(d != 0)
       
           private val g = gcd(n.abs, d.abs)
           val numer = n / g
           val denom = d / g
       
           def this(n: Int) = this(n, 1)
       
           def + (that: Rational): Rational =
             new Rational(
               numer * that.denom + that.numer * denom,
               denom * that.denom
             )
       
           def + (i: Int): Rational =
             new Rational(numer + i * denom, denom)
       
           def - (that: Rational): Rational =
             new Rational(
               numer * that.denom - that.numer * denom,
               denom * that.denom
             )
       
           def - (i: Int): Rational =
             new Rational(numer - i * denom, denom)
       
           def * (that: Rational): Rational =
             new Rational(numer * that.numer, denom * that.denom)
       
           def * (i: Int): Rational =
             new Rational(numer * i, denom)
       
           def / (that: Rational): Rational =
             new Rational(numer * that.denom, denom * that.numer)
       
           def / (i: Int): Rational =
             new Rational(numer, denom * i)
       
           override def toString = numer + "/" + denom
       
           private def gcd(a: Int, b: Int): Int = 
             if (b == 0) a else gcd(b, a % b)

       }
defined class Rational

scala> val x = new Rational(2, 3)
x: Rational = 2/3

scala> x * x
res12: Rational = 4/9

scala> x * 2
res13: Rational = 4/3

scala> 2 * r
<console>:10: error: overloaded method value * with alternatives:
  (x: Double)Double <and>
  (x: Float)Float <and>
  (x: Long)Long <and>
  (x: Int)Int <and>
  (x: Char)Int <and>
  (x: Short)Int <and>
  (x: Byte)Int
 cannot be applied to (Rational)
              2 * r
                ^

scala> val r = new Rational(2,3)
r: Rational = 2/3

scala> 2 * r
res15: Rational = 4/3