decorator

☆decorator↑

package main
import "fmt"

type staff struct {
    payment float;
}

type employee interface {
    getOvertimePay() float;
}

func showOvertimePay(e employee, name string) {
    fmt.Printf("%s: I'm getting %f yen. Haha!\n", 
        name, e.getOvertimePay()
    );
}

func (self *staff) getOvertimePay() float {
    return self.payment;
}

type beTechnical struct {
    prototype employee;
}

func (self *beTechnical) getOvertimePay() float {
    return self.prototype.getOvertimePay() * 1.1;
}

type beLicensed struct {
    prototype employee;
}

func (self *beLicensed) getOvertimePay() float {
    return self.prototype.getOvertimePay() * 1.2;
}

type beManager struct {
    prototype employee;
}

func (self *beManager) getOvertimePay() float {
    return 0;
}

type beTemporary struct {
    prototype employee;
}

func (self *beTemporary) getOvertimePay() float {
    return 1000;
}

func main() {
    john := &beTechnical{&beLicensed{&staff{1000}}};
    showOvertimePay(john, "John");
    
    elen := &beTemporary{&beTechnical{&staff{1000}}};
    showOvertimePay(elen, "Elen");
}