gooptions.go

package main

import "time"


// https://dave.cheney.net/2014/10/17/functional-options-for-friendly-apis
type Client struct {
	addr string 
	timeout time.Duration
}

type Option func(client *Client)

func NewClient(opts ...Option) Client {
	client := Client{}
	for _, opt := range opts {
		opt(&client)
	}
	return client
}

func Addr(addr string) Option {
	return Option(func(client *Client) {
		client.addr = addr
	}) 
}

func Timeout(timeout time.Duration) Option {
	return Option(func(client *Client) {
		client.timeout = timeout
	}) 
}

// How to use 
func main() {
	client := NewClient(Addr("127.0.0.1"), Timeout(2 * time.Second))
}