awesome-patterns/structural/decorator/decorate.go

package main

import "log"

type Object func(int) int

func LogDecorate(fn Object) Object {
	return func(n int) int {
		log.Println("Starting the execution with the integer", n)

		result := fn(n)

		log.Println("Execution is completed with the result", result)

		return result
	}
}

func Double(n int) int {
	return n * 2
}

func main() {
	f := LogDecorate(Double)
	f(5)
}

// Starting execution with the integer 5
// Execution is completed with the result 10