Currying examples. Used in Scala mainly for type inference algorithms

Currying example.scala

def sum(x: Int)(y: Int)(z: Int) = x + y + z

val curriedWithMultipleArguments = sum _

val addToNine = curriedWithMultipleArguments(4,5)

addToNine(3)

Methods.scala

// defining a method using def for a curried function

def plusMethod (a: Int)(b: Int) = a + b          //> plusMethod: (a: Int)(b: Int)Int
  
 val functions = List(1,2,3) map plusMethod       //> functions  : List[Int => Int] = List(<function1>, <function1>, <function1>)
                                                  //| 
 functions(0)(1)                                  //> res2: Int = 2
 
 // take the function (the underscore) and apply it to the number 5
 
 functions map {_ (5) }                           //> res3: List[Int] = List(6, 7, 8)

PlusExampe.scala

// demonstrating function currying
  
  val plus = {(a: Int, b: Int) => a + b }         //> plus  : (Int, Int) => Int = <function2>
                              // the inner function, a value is a closure
  val plusCurry = { a: Int => { b: Int => a + b } }
                                                  //> plusCurry  : Int => (Int => Int) = <function1>
  val plus1 = plusCurry(1)                        //> plus1  : Int => Int = <function1>
  
  plus1(2)                                        //> res0: Int = 3
  
  plusCurry(1)(2)                                 //> res1: Int = 3