Hey, I have just reduced the price for all products. Let's prepare our programming skills for the post-COVID era. 
Decorator in Go
Decorator is a structural pattern that allows adding new behaviors to objects dynamically by placing them inside special wrapper objects.
Using decorators you can wrap objects countless number of times since both target objects and decorators follow the same interface. The resulting object will get a stacking behavior of all wrappers.
Conceptual Example
pizza.go: Component interface
package main
type pizza interface {
getPrice() int
}
veggieMania.go: Concrete component
package main
type veggeMania struct {
}
func (p *veggeMania) getPrice() int {
return 15
}
tomatoTopping.go: Concrete decorator
package main
type tomatoTopping struct {
pizza pizza
}
func (c *tomatoTopping) getPrice() int {
pizzaPrice := c.pizza.getPrice()
return pizzaPrice + 7
}
cheeseTopping.go: Concrete decorator
package main
type cheeseTopping struct {
pizza pizza
}
func (c *cheeseTopping) getPrice() int {
pizzaPrice := c.pizza.getPrice()
return pizzaPrice + 10
}
main.go: Client code
package main
import "fmt"
func main() {
pizza := &veggeMania{}
//Add cheese topping
pizzaWithCheese := &cheeseTopping{
pizza: pizza,
}
//Add tomato topping
pizzaWithCheeseAndTomato := &tomatoTopping{
pizza: pizzaWithCheese,
}
fmt.Printf("Price of veggeMania with tomato and cheese topping is %d\n", pizzaWithCheeseAndTomato.getPrice())
}
output.txt: Execution result
Based on: Golang By Example
