Design Pattern in GO

options-pattern.go

package main

import "fmt"

func main() {
	dummy := NewDummy()
	fmt.Println(dummy.Lorem)
	fmt.Println(dummy.Ipsum)

	dummy.Lorem = "test"
	dummy.Ipsum = "test2"
	fmt.Println(dummy.Lorem)
	fmt.Println(dummy.Ipsum)

	dummy2 := NewDummy(Lorem("lorem"), Ipsum("ipsum"))
	fmt.Println(dummy2.Lorem)
	fmt.Println(dummy2.Ipsum)
}

type Dummy struct {
	Lorem string
	Ipsum string
}

type Option func(*Dummy)

func Lorem(lorem string) Option {
	return func(dummy *Dummy) {
		dummy.Lorem = lorem
	}
}

func Ipsum(ipsum string) Option {
	return func(dummy *Dummy) {
		dummy.Ipsum = ipsum
	}
}

func NewDummy(opts ...Option) *Dummy {
	dummy := &Dummy{}

	for _, opt := range opts {
		opt(dummy)
	}

	return dummy
}