Function Memorization in Go (https://mostafa-asg.github.io/posts/function-memorization-in-go/)

main.go

package main

type FuncIntInt func(int) int

func memorized(fn FuncIntInt) FuncIntInt {
	cache := make(map[int]int)

	return func(input int) int {
		if val, found := cache[input]; found {
			println("Read from cache")
			return val
		}

		tmp := fn(input)
		cache[input] = tmp
		return tmp
	}
}

func main() {

	var memFact FuncIntInt

	memFact = memorized(func(n int) int {
		if n <= 1 {
			return 1
		}
		return n * memFact(n-1)
	})

	println(memFact(5))
	println("-------------")
	println(memFact(4))
	println("-------------")
	println(memFact(3))

	/* --------------------
	// OUTPUT :
	120
	-------------
	Read from cache
	24
	-------------
	Read from cache
	6
	----------------------*/
}