go without if statements

main.go

package main

import (
  fmt
)

func main() {
	type fnType = func(a int, b int) int
	fnMap := map[string]fnType{
		"ADD": func(a int, b int) int {
			return a + b
		},
		"SUB": func(a int, b int) int {
			return a - b
		},
	}

	// closure
	localFn := func(method string) fnType {
		return fnMap[method] // returns a function
	}

	printer := func(fn func(method string) fnType, method string) {
		fmt.Println(fn(method)(10, 5)) // callback
	}

  	// Victory
  	printer(localFn, "ADD")
	printer(localFn, "SUB")
}