Functional Randomness with Languages

functions.go

package main

import "fmt"

type Lx func(int) int
type Fx func(int) Lx
type Mx func(int) Fx

func cmbSum(a int, b int) Mx {
	return func(c int) Fx {
		return func(d int) Lx {
			return func(e int) int {
				return (a + b + c + d) * e
			}
		}
	}
}

func cmb(a Lx, b Lx) Lx {
	return func(c int) int {
		return b(a(c))
	}
}

func inc(x int) int {
	return x + 1
}

func sum(x int) int {
	result := 0

	for i := 0; i < x; i++ {
		result += i
	}

	return result
}

func main() {
	n := 333

	x := cmb(inc, sum)(n)

	a := cmbSum(x, x)
	b := a(x)
	c := b(x)
	d := c(2)
	fmt.Println(x)
	// prints 55611
	fmt.Println(cmbSum(x, x)(x)(x)(2))
	// prints 444888
	fmt.Println(d)
	// prints 444888
}

functions.hs

cmbSumH :: Num a => a -> a -> a -> a -> a -> a
cmbSumH a b c d e = (a + b + c + d) * e

cmbH :: (t2 -> t1) -> (t1 -> t) -> t2 -> t
cmbH a b c = b(a(c))

incH :: Int -> Int
incH x = x + 1

sumH :: (Enum a, Num a) => a -> a
sumH x = sum [1..(x - 1)]

main = do
    let n = 333

    let x = cmbH incH sumH n

    let a = cmbSumH x x
    let b = a x
    let c = b x
    let d = c 2

    print (x)
    -- prints 55611
    print (cmbSumH x x x x 2)
    -- prints 444888
    print d
    -- prints 444888

functions.scala

object FunctionTest {
  def cmbSum(a:Int)(b:Int)(c:Int)(d:Int)(e:Int) = (a + b + c + d) * e

  def cmb[A, B](a: Int => A)(b: A => B)(c: Int) = b(a(c))

  def inc(x:Int):Int = x + 1

  def sum(x:Int):Int = (1 to (x - 1)).reduceLeft(_ + _)

  def main(args: Array[String]) {
    val n = 333

    val x = cmb(inc)(sum)(n)

    val a = cmbSum(x)(x)(_)
    val b = a(x)(_)
    val c = b(x)(_)
    val d = c(2)

    println(x)
    // prints 55611
    println(cmbSum(x)(x)(x)(x)(2))
    // prints 444888
    println(d)
    // prints 444888
  }
}