package main

import (
	"fmt"
	"strings"
)

func main() {
	decorator1(hi)("world")
	println()

	f := decorator2(hello)
	f("world")
}

func decorator1(f func(s string) error) func(s string) error {
	return func(s string) error {
		fmt.Println("hello hello hello")
		e := f(s)
		return e
	}
}

func decorator2(f func(s string)) func(s string) {
	return func(s string) {
		fmt.Println("hello hello hello")
		f(s)
	}
}

func hi(s string) error {
	fmt.Println("hi " + strings.Repeat(s, 3))
	return nil
}

func hello(s string) {
	fmt.Println("hi " + strings.Repeat(s, 3))
}