sandbox.scala

/* Created with info from here: 
 * https://learnxinyminutes.com/docs/scala/
 */


object SandBox {
    def main(args: Array[String]): Unit = {
        val str: String = "hello world C"
        println("------------------------------------------")
        println(">string methods")
        println(str.length)
        println(str.substring(2, 6))
        println(str.replace("C", "E"))
        println(str.take(5))
        println(str.drop(5))
        
        println(">val immutable, var isn't")
        val n = 45
        println(">print vars via $var notation")
        println(s"We have $n apples")
        val a = Array(11, 9, 6)
        println(s"My second daughter is ${a(0) - a(2)} years old")
        println(s"We have double the amount of ${n / 2.0} in apples")
        
        println(">usage of functions")
        var sum: Int = sumOfSquares(2, 3)
        println(sum)
        def subtract(x: Int, y:Int): Int = x - y
        println(subtract(5, 2))
        def addWithDefault(x: Int, y: Int = 5) = x + y
        println(addWithDefault(5))
        println(addWithDefault(1, 11))
        println(">anonymous function definition")
        val sq: Int => Int = x => x * x
        println(sq(10))
        val addOne: Int => Int = _ + 1
        println(addOne(2))
        val weirdSum: (Int, Int) => Int = (_ * 2 + _ * 3)
        println(weirdSum(2, 3))
        
        println(">loops and shit")
        val rng = 1 to 5
        rng.foreach(println)
        (5 to 1 by -2) foreach (println)
        var i = 0
        while(i < 10) {println("i " + i); i+=1}
        i = 0
        do {
          println("i is still less than 10")
          i += 1
        }while(i < 10)

        print(">recursion\n")
        showNumbersInRange(1, 14)

        val x = 10
        print(">conditionals\n")
        if (x == 1) println("yeah")
        if (x == 10) println("yeah")
        if (x == 11) println("yeah") else println("nay")
        println(if (x==10) "yeah" else "nay")
        val text = if (x == 10) "yeah" else "nope"
        
        println(">data structures")
        val arr = Array(1, 2, 3, 4, 5)
       
        val map = Map("fork" -> "tenedor", "spoon" -> "cuchara", "knife" -> "cuchillo")
        println(map("fork"))

        val set = Set(1, 3, 7)
        println(set(1))

        val divideInts = (x: Int, y: Int) => (x / y, x % y)
        val d = divideInts(10, 3)
        println(d._1)
        println(d._2)
        val (div, mod) = divideInts(10, 3)
        println(div, mod)

        println(">classes")
        val bobik = new Dog("greyhound")
        println(bobik.breed)
        println(bobik.bark)
        val sharik = Dog
        println(sharik.allKnownBreeds)

        println("> case classes")
        val george = Person("George", "1234")
        val kate = Person("Kate", "4567")
        println(george.phoneNumber)
        
        val zhora = george.copy(phoneNumber = "9876")
        println(zhora.phoneNumber)
        
        println(">traits")
        // TODO: pattern matching and traits
        
        println("> functional programming")
        val add10: Int => Int = _ + 10
        println(List(1, 2, 3) map add10)
        println(List(1, 2, 3) map (x => x * 2))
        List("Dom", "Bob", "Natalia") foreach println

        var s = List(4, 5 ,6)
        val sSquared = s map (x => x * x)
        println(sSquared)
        println(sSquared.filter(_ < 20)(0))
        println(sSquared.reduce(_ + _))
        println(List(1, 2, 3) filter (_ > 2))

        // TODO: for comprehensions
        println("------------------------------------------")

    }
    // definition of function
    def sumOfSquares(x: Int, y: Int): Int = {
      val x2 = x * x
      val y2 = y * y
      x2 + y2
    }

    def showNumbersInRange(a: Int, b: Int): Unit = {
      print(a +"\n")
      if (a < b)
        showNumbersInRange(a + 1, b)
    }
}


class Dog(br: String){
  var breed: String = br 
  def bark = "Woof, woof!"
  private def sleep(hours: Int) = 
    println(s"I'm sleeping for $hours hours")
}


object Dog{
  def allKnownBreeds = List("pitbull", "shepherd", "retriever")
  def createDog(breed: String) = new Dog(breed)
}

case class Person(name: String, phoneNumber: String)