1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
| package main
import (
"fmt"
"time"
)
type Conn struct {
Host string
Port int
Timeout time.Duration
Retry int
}
func NewConn(
host string, // 必填参数
fs ...func(*Conn), // 可选可变参数
) *Conn {
conn := &Conn{
Host: host,
}
for _, f := range fs {
f(conn)
}
return conn
}
func withPort(port int) func(*Conn) {
return func(c *Conn) {
c.Port = port
}
}
func withTimeout(duration time.Duration) func(*Conn) {
return func(c *Conn) {
c.Timeout = duration
}
}
func withRetry(retry int) func(*Conn) {
return func(c *Conn) {
c.Retry = retry
}
}
func main() {
con := NewConn(
"localhost",
withRetry(3),
withPort(8080),
withTimeout(2*time.Second),
)
fmt.Printf("%#v", con)
}
|