Golang策略模式如何实现算法解耦

type DiscountStrategy interface {
    Calculate(price float64) float64
}

type NormalUserDiscount struct{}
<p>func (d <em>NormalUserDiscount) Calculate(price float64) float64 {
return price </em> 0.95 // 95折
}</p><p>type VIPUserDiscount struct{}</p><p>func (d <em>VIPUserDiscount) Calculate(price float64) float64 {
return price </em> 0.9 // 9折
}</p><p>type SuperUserDiscount struct{}</p><p>func (d <em>SuperUserDiscount) Calculate(price float64) float64 {
return price </em> 0.8 // 8折
}</p>

type PriceCalculator struct {
    strategy DiscountStrategy
}
<p>func (c *PriceCalculator) SetStrategy(s DiscountStrategy) {
c.strategy = s
}</p><p>func (c *PriceCalculator) GetFinalPrice(price float64) float64 {
if c.strategy == nil {
panic("strategy not set")
}
return c.strategy.Calculate(price)
}</p>

calculator := &PriceCalculator{}
<p>var strategy DiscountStrategy</p><p>switch userType {
case "normal":
strategy = &NormalUserDiscount{}
case "vip":
strategy = &VIPUserDiscount{}
case "super":
strategy = &SuperUserDiscount{}
}</p><p>calculator.SetStrategy(strategy)
finalPrice := calculator.GetFinalPrice(100)</p>