类类型作为在Scala中的地图中的键

本文介绍了类类型作为在Scala中的地图中的键的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我的游戏有

class Enemy 谁是AI /功能我可以改变

trait移动 trait VerticalMover扩展移动 trait RandomMover扩展移动

等。现在我需要基于trait获取预加载的东西。我想做的是有一个地图，接受所有的traits，扩展移动作为键，然后一些EnemyContainer作为值将具有trait相关内容预加载。

但是如何我定义这样的地图，以及如何格式化我的.get（）来获取容器的一些敌人的实例。像：

val myEnemy = new Enemy with RandomMover val myDetails：EnemyContainer = enemyDetailsS​​tore.get（myEnemy.getClass ）

解决方案

Map [Class [_< ;: Moving]，EnemyDetails] 类型。我怀疑像：

//给出一个Map [Class [_< ;: Moving]，EnemyDetails]键 enemyDetailsS​​tore.filterKeys（_ isInstance myEnemy）

或：

// Iterable [EnemyDetails] enemyDetailsS​​tore collect {case（c，d）if c isInstance myEnemy => d}

或者只是：

//选项[EnemyDetails] enemyDetailsS​​tore collectFirst {case（c，d）if c isInstance myEnemy => d}

会为你做。这个代码的唯一问题是它是O（N），因为它需要一个遍历的地图，而不是简单的查找，这将是O（1）或O（log N）

My game has

class Enemy

who's AI/functionality I can change with

trait Moving trait VerticalMover extends Moving trait RandomMover extends Moving

and so on. Now I need to fetch preloaded stuff based on trait. What I would like to do is have a Map that accepts all traits that extend Moving as keys and then some EnemyContainer as value that would have trait related content preloaded.

But how do I define such a Map and how do format my .get() to get the container by an instance of some Enemy. Something like:

val myEnemy = new Enemy with RandomMover val myDetails:EnemyContainer = enemyDetailsStore.get(myEnemy.getClass)

解决方案

Well, I assume that your enemy details store is of type Map[Class[_ <: Moving], EnemyDetails]. I suspect that something like:

//gives a Map[Class[_ <: Moving], EnemyDetails] for all matching keys enemyDetailsStore.filterKeys(_ isInstance myEnemy)

Or:

//Iterable[EnemyDetails] enemyDetailsStore collect { case (c, d) if c isInstance myEnemy => d }

Or even just:

//Option[EnemyDetails] enemyDetailsStore collectFirst { case (c, d) if c isInstance myEnemy => d }

Will do for you. The only "issue" with this code is that it's O(N), in that it requires a traversal of the map, rather than a simple lookup, which would be O(1), or O(log N)