Scala Closure Demo

Fraction.java

public class Fraction {
  private final int num;
  private final int denom;
  
  public Fraction(int num, int denom) {
    this.num = num;
    this.denom = denom;
  }
  
  public int getNum() {
    return num;
  }
  
  public int getDenom() {
    return denom;
  }
  
  public Fraction add(Fraction other) {
    // Ignore cases where denom is 0 or other.denom is 0 or other is null. Also assume the denom are the same for both fractions
    return new Fraction(num + other.num, denom)
  }
  
  public Fraction subtract(Fraction other) {
    // Ignore cases where denom is 0 or other.denom is 0 or other is null. Also assume the denom are the same for both fractions
    return new Fraction(num - other.num, denom)
  }
}

Fraction.scala

class Fraction(val num: Int, val denom: Int) {
  def +(that: Fraction) = {
    op(that) { _ + _ }
  }
  
  def -(that: Fraction) = {
    op(that) { _ - _ }
  }
  
  private def op(that: Fraction)(f: (Int, Int) => Int) = {
    // Common error handling goes here. Also goes logic to find LCD if denom are not the same 
    new Fraction(f.apply(num, that.num), denom)
  }
}