mirror of
https://github.com/crazybber/awesome-patterns.git
synced 2024-11-25 22:36:05 +03:00
119 lines
2.5 KiB
Go
119 lines
2.5 KiB
Go
// 存疑部分.
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//
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// 这里是以玩家的健康状态为基准，影响生命回复和受到伤害的例子，有三个状态[健康HealthyState|受伤WoundedState|死亡DeadState].
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// 和main.go中的跷跷板例子由行为驱动状态变化不同.以下例子的行为是受到数据影响的,结果就是达不到完全消除if-else的效果
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//
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// 疑问：
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// 1. 很多地方说状态模式可以消除if-else，事实上要做到自行的状态切换很多时候还是会用到if-else，这里的消除应当是指
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// 将巨大的条件语句拆分开(?)
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// 2. 还是说这种由数据决定状态的事务逻辑下不适合使用状态模式
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package main
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import (
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"errors"
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"fmt"
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)
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// state
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type PlayerState interface {
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Heal(p *Player) error
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Hurt(p *Player ,dmg int)
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}
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type HealthyState struct {}
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func (h HealthyState)Heal(p *Player) error{
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return nil
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}
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func (h HealthyState)Hurt(p *Player ,dmg int){
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if dmg > 0 && dmg < p.MaxHealth{
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p.Health = p.Health - dmg
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p.State = WoundedState{}
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}else if dmg > p.MaxHealth{
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p.Health = 0
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p.State = DeadState{}
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}
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}
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type WoundedState struct {}
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func (WoundedState)Heal(p *Player) error{
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if p.Health >= p.MaxHealth - 5{
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fmt.Printf("healing from %d to %d\n" ,p.Health ,p.MaxHealth)
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p.State = HealthyState{}
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p.Health = p.MaxHealth
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}else{
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fmt.Printf("healing from %d to %d\n" ,p.Health ,p.Health+5)
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p.Health = p.Health + 5
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}
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return nil
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}
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func (h WoundedState)Hurt(p *Player ,dmg int){
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if p.Health > dmg{
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p.Health = p.Health - dmg
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}else {
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p.State = DeadState{}
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p.Health = 0
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}
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}
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type DeadState struct {}
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func (DeadState)Heal(P *Player) error{
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return errors.New("you are dead")
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}
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func (DeadState)Hurt(P *Player ,dmg int){}
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// context
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type Player struct {
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Health int
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MaxHealth int
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State PlayerState
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}
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func (p *Player)HealPlayer()error{
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return p.State.Heal(p)
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}
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func (p *Player)HurtPlayer(damage int){
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fmt.Printf("damage %d\n" ,damage)
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p.State.Hurt(p ,damage)
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}
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//func main(){
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// player := &Player{
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// Health:100,
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// MaxHealth:100,
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// State:HealthyState{},
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// }
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//
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// rand.Seed(time.Now().UnixNano())
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// for i:=0 ;i<10 ;i++{
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// if err := player.HealPlayer();err != nil{
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// fmt.Println(err)
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// break
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// }
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// player.HurtPlayer(rand.Intn(30))
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// }
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// /*
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// output:
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// damage 28
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// healing from 72 to 77
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// damage 29
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// healing from 48 to 53
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// damage 15
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// healing from 38 to 43
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// damage 1
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// healing from 42 to 47
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// damage 19
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// healing from 28 to 33
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// damage 27
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// healing from 6 to 11
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// damage 16
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// you are dead
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// */
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//}
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