Functional.scala

case class Score(p1: Int, p2: Int)

// Alles ist eine Expression
val score = Score(5, 1)

val winner = if (score.p1 > score.p2) "Player 1" else "Player 2"
val looser = if (score.p1 > score.p2) "Player 2" else "Player 1"

// Tupel
val winnerLooser =
  if (score.p1 > score.p2) ("Player 1", "Player 2")
  else ("Player 2", "Player 1")
    
// Tupel Zugriff
s"Gewinner: ${winnerLooser._1}; Verlierer: ${winnerLooser._2}"

// Funktionen
def lessThan(max: Int, value: Int) = value < max

// Partial applied functions
val lessThan5 = lessThan(max = 5, _: Int)
val lessThan10 = lessThan(max = 10, _: Int)

val numbers: List[Int] = List(1, 2, 3, 6, 8, 34, 17, 42, 54, 100, 117, 1337)
  
numbers.filter(lessThan5)
numbers.filter(lessThan10)

// functional composition
def double(x: Int) = x * 2
def plusTwo(x: Int) = x + 2
val doubleAndPlusTwo = double _ andThen plusTwo _

val result = doubleAndPlusTwo(5)

// Ranges
  
val oneToFive = 1 to 5
  
for (i <- 1 to 5) {
	println(i)
}
  
for (i <- 1 to 5; if i % 2 == 0) {
	println(i)
}
  
// For comprehension
for {
	i <- 1 to 5
	if i % 2 == 0
} yield i
  
val players = List("Timo", "Jan", "Lothar", "Sven", "Danny")

val playerPairs = for {
  p1 <- players
  p2 <- players
  if p1 != p2
} yield (p1, p2)

// lazy Evaluation
lazy val lazyPlayerPairs = for {
  p1 <- players
  p2 <- players
  if p1 != p2
} yield (p1, p2)
  

println(lazyPlayerPairs)