Currying

object Main {
  def add(a: Int)(b: Int): Int = a + b
  def main(args: Array[String]): Unit = {
    println(add(3)(4))
  }
}

object Main {
  def combine(prefix: String)(value: Int): String = s"$prefix$value"
  def main(args: Array[String]): Unit = {
    println(combine("id-")(42))
  }
}

object Main {
  def add(a: Int)(b: Int): Int = a + b
  def main(args: Array[String]): Unit = {
    val addFive = add(5) _
    println(addFive(10))
    println(addFive(20))
  }
}

object Main {
  def power(exp: Int)(base: Int): Int = math.pow(base, exp).toInt
  def main(args: Array[String]): Unit = {
    val square = power(2) _
    val cube = power(3) _
    println(square(5))
    println(cube(2))
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val add = (a: Int, b: Int) => a + b
    val curriedAdd = add.curried
    println(curriedAdd(3)(4))
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val curried: Int => Int => Int = a => b => a + b
    val normal = Function.uncurried(curried)
    println(normal(3, 4))
  }
}

object Main {
  def discount(rate: Double)(price: Double): Double = price * (1 - rate)
  def main(args: Array[String]): Unit = {
    val blackFriday = discount(0.3) _
    println(blackFriday(100))
    println(blackFriday(250))
  }
}

object Main {
  def fold[A](xs: List[A])(init: A)(op: (A, A) => A): A =
    xs.foldLeft(init)(op)
  def main(args: Array[String]): Unit = {
    val total = fold(List(1, 2, 3))(0)((a, b) => a + b)
    println(total)
  }
}

object Main {
  def make(a: Int)(b: Int)(c: Int): Int = a + b + c
  def main(args: Array[String]): Unit = {
    println(make(1)(2)(3))
    val step = make(10) _
    println(step(20)(30))
  }
}

object Main {
  def atLeast(min: Int)(value: Int): Boolean = value >= min
  def main(args: Array[String]): Unit = {
    val adult = atLeast(18) _
    println(List(15, 21, 18, 12).map(adult))
  }
}

object Main {
  def greet(greeting: String)(name: String): String = s"$greeting, $name!"
  def main(args: Array[String]): Unit = {
    val sayHi = greet("Hi") _
    println(sayHi("Ann"))
    println(sayHi("Bob"))
  }
}