Uncurried functions

uncurrying.kt

[Test] fun testUncurrying() {
    val sum2ints: (Int, Int) -> Int = { x, y -> x + y }
    val curried: (Int) -> (Int) -> Int = sum2ints.curried()
    assertEquals(curried(2)(4), 6)
    //same type as sum2ints,
    val back: (Int, Int) -> Int = curried.uncurried()
    assertEquals(back(2, 4), 6)
    assertEquals(sum2ints(2, 4), 6)
    
    val sum3ints: (Int, Int, Int) -> Int = { x, y, z -> x + y }
    val f: (Int) -> (Int) -> (Int) -> Int =sum3ints.curried()
    val x: (Int, Int, Int) -> Int =f.uncurried()
}