golang 高阶函数使用 Functional Options
package mainimport ( "crypto/tls" "fmt" "time")// 业务实体type Server struct { Addr string Port int Protocol string Timeout time.Duration MaxConns int TLS *tls.Config}// 高阶函数type Option func(*Server)func Protocol(p string) Option { return func(server *Server) { server.Protocol = p }}func Timeout(timeout time.Duration) Option { return func(server *Server) { server.Timeout = timeout }}func MaxConns(maxconns int) Option { return func(server *Server) { server.MaxConns = maxconns }}func TLS(tls *tls.Config) Option { return func(server *Server) { server.TLS = tls }}func NewServer(addr string, port int, options ...func(*Server)) (*Server, error) { serv := Server{ Addr: addr, Port: port, Protocol: "tcp", Timeout: 30 * time.Second, MaxConns: 1000, TLS: nil, } for _, option := range options { option(&serv) } return &serv, nil}func main() { server, _ := NewServer("127.0.0.1", 9999, Protocol("UDP"), MaxConns(100)) fmt.Println(server.Protocol) fmt.Println(server.MaxConns)}
