// Lecture 1

//==========

//**Assignments (values)**

//(variable names should be lower case)

//=====================================

val x = 42

val y = 3 + 4

//**Collections**

//===============

List(1,2,3,1)

Set(1,2,3,1)

1 to 10

(1 to 10).toList

(1 until 10).toList

// an element in a list

List(1, 2, 3, 1)(0)

List(1, 2, 3, 1)(3)

1::2::3::Nil

List(1, 2, 3) ::: List(4, 5, 6)

//**Printing/Strings**

//====================

println("test")

val tst = "This is a " + "test" 

println(tst)

val lst = List(1,2,3,1)

println(lst.toString)

println(lst.mkString("\n"))

// some methods take more than one argument

println(lst.mkString("[", ",", "]"))

//**Conversion methods**

//======================

List(1,2,3,1).toString

List(1,2,3,1).toSet

"hello".toList

1.toDouble

//**Types**

//=========

// Int, Long, BigInt, Float, Double

// String, Char

// List[Int], Set[Double]

// Pairs: (Int, String)        

// List[(BigInt, String)]

//**Smart Strings**

//=================

println(">\n<")

println(""">\n<""")

/* in Java

val lyrics = "Baa, Baa, Black Sheep \n" +

             "Have you any wool? \n" +

             "Yes, sir, yes sir \n" +

             "Three bags full"

*/ 

val lyrics = """Baa, Baa, Black Sheep  

                |Have you any wool?

                |Yes, sir, yes sir

                |Three bags full""".stripMargin

println(lyrics)

//**Pairs/Tuples**

//================

val p = (1, "one")

p._1

p._2

val t = (4,1,2,3)

t._4

//**Function Definitions**

//========================

def square(x: Int): Int = x * x

//**Ifs control structures**

//==========================

def fact(n: Int): Int = 

  if (n == 0) 1 else n * fact(n - 1)

def fact2(n: BigInt): BigInt = 

  if (n == 0) 1 else n * fact2(n - 1)

def fib(n: Int): Int =

  if (n == 0) 1 else

    if (n == 1) 1 else fib(n - 1) + f(n - 2)

//a recursive function

def gcd(x: Int, y: Int): Int = 2 //??? 

//**String Interpolations**

//=========================

//**Assert/Testing**

====================

//**For-Maps (not For-Loops)**

//============================

for (n <- (1 to 10).toList) yield square(n)

for (n <- (1 to 10).toList; m <- (1 to 10).toList) yield m * n

val mtable = for (n <- (1 to 10).toList; m <- (1 to 10).toList) yield m * n

mtable.sliding(10,10).toList.mkString(

// webpages